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30V, 5-10A bench PSU recommendations?
I have a couple of linear PSU's (Weir, both 30V-2A, 15V-4A) but they
are both old and are now non-functional / iffy and I was considering something newer, lighter, smaller and with twin digital displays (on the Weir's you have to switch between displaying V and A). There are loads over the normal suppliers but I wondered if anyone here had got something reasonably recently that they could recommend? It's for general use, (temporarily) powering 5/12V things, charging the odd battery and the like. A 10A capacity might mean it can batter handle a 5A output, quieter the better (some use small heatsinks and small fans) and ideally under say £100? I did look at kits (good to know you have the cct diagram) but that's probably not best done with a SMPSU and linear stuff also seems to require large heatsinks and heavy switching devices, all taking extra time to source/ build (unless a complete kit with case / hardware etc). Cheers, T i m |
30V, 5-10A bench PSU recommendations?
In message , T i m
writes There are loads over the normal suppliers but I wondered if anyone here had got something reasonably recently that they could recommend? I, and quite a few people I know, regularly use units from Maplins and Circuit Specialists (Europe) with excellent results, although our use is operating ancient (open frame) and modern (can) electric motors (toy trains), where voltage requirements can be anywhere from 4 to 30, and amps less than an amp to 5 amps. I don't think the Maplin units are available unused now, but CSE units are : https://www.circuitspecialists.eu/po...er-supplies/sw itch-mode-dc-bench-power-supply-adjustable-0-30v-0-5a-csi-3005sm/ Highly recommended. 10amp unit also available. -- Graeme |
30V, 5-10A bench PSU recommendations?
On Tue, 15 Sep 2020 15:31:23 +0100, Graeme
wrote: In message , T i m writes There are loads over the normal suppliers but I wondered if anyone here had got something reasonably recently that they could recommend? I, and quite a few people I know, regularly use units from Maplins and Circuit Specialists (Europe) with excellent results, I forget about Maplins these days. ;-( although our use is operating ancient (open frame) and modern (can) electric motors (toy trains), where voltage requirements can be anywhere from 4 to 30, and amps less than an amp to 5 amps. Yes, something I discovered when automating a section of BIL's model railway layout with an Arduino and using PWM. On the same settings, one loco would hardly move and another would fly off the track! I don't think the Maplin units are available unused now, but CSE units are : https://www.circuitspecialists.eu/po...er-supplies/sw itch-mode-dc-bench-power-supply-adjustable-0-30v-0-5a-csi-3005sm/ That's spooky Graeme, that looks *exactly* the same as the one my mate had in his PC shop and *we* used many times, till he sold up (and took it with him). ;-( My only criticism of it (and we shared it actually) is that it was easy to grab the 'Coarse' rather than 'Fine' knob if you were doing something on the fly. Apart from that, it always did what we asked of it and was pretty compact (and being portrait rather than landscape, took up very little shelf space). ;-) Highly recommended. That's the sort of thing I was hoping for, thanks. ;-) 10amp unit also available. Looking at the price difference (nearly double) and assuming the 5A model really can source 5A continuously (for 8 hours it says) then I might just go with that, certainly for now. Cheers, T i m p.s. With the advent of all these electric scooters and cycles, some of which running 36V+ battery systems I'm wondering if a 50V (3A) might be of use to me? Circuitspecialists do a 50V / 3A linear PSU that just sneaks in under my price limit. ;-) My iCharger can 'boost' the output voltage over the input voltage: https://www.icharger.co.nz/icharger-1010b And has the balance feature so I might stick with that for the batteries. |
30V, 5-10A bench PSU recommendations?
Graeme formulated on Tuesday :
I don't think the Maplin units are available unused now, but CSE units are : https://www.circuitspecialists.eu/power-supplies/bench-power-supplies/switch-mode-dc-bench-power-supply-adjustable-0-30v-0-5a-csi-3005sm/ ; Highly recommended. 10amp unit also available. My Maplin unit recently took out it's voltage/current sensing IC, repaired now and I suspect it was just an isolated failure of the IC. |
30V, 5-10A bench PSU recommendations?
In message , T i m
writes On Tue, 15 Sep 2020 15:31:23 +0100, Graeme wrote: Highly recommended. That's the sort of thing I was hoping for, thanks. ;-) Tim, should you ever see an advert for a vintage train show, almost any display running 0 gauge or larger will be using Maplin or CSE units. I belong to various groups and hear nothing but praise for them, and use them myself. There are others, designed for the job, that are just not up to it, particularly all day events, to the extent that people build frames with cooling fans to prevent overheating and cut out. No such problems reported with the Maplin/CSE units. I have also found CSE to be approachable and helpful, should the need arise. Cheers, -- Graeme |
30V, 5-10A bench PSU recommendations?
In message
Graeme wrote: In message , T i m writes There are loads over the normal suppliers but I wondered if anyone here had got something reasonably recently that they could recommend? I, and quite a few people I know, regularly use units from Maplins and Circuit Specialists (Europe) with excellent results, although our use is operating ancient (open frame) and modern (can) electric motors (toy trains), where voltage requirements can be anywhere from 4 to 30, and amps less than an amp to 5 amps. I don't think the Maplin units are available unused now, but CSE units are : https://www.circuitspecialists.eu/po...er-supplies/sw itch-mode-dc-bench-power-supply-adjustable-0-30v-0-5a-csi-3005sm/ Highly recommended. 10amp unit also available. I have and use the CSI 3005T 30volt 5amp version Definitely recommended, it charged my car battery no probs. -- John Bryan |
30V, 5-10A bench PSU recommendations?
On Tuesday, 15 September 2020 15:31:41 UTC+1, Graeme wrote:
In message , T i m writes There are loads over the normal suppliers but I wondered if anyone here had got something reasonably recently that they could recommend? I, and quite a few people I know, regularly use units from Maplins and Circuit Specialists (Europe) with excellent results, although our use is operating ancient (open frame) and modern (can) electric motors (toy trains), where voltage requirements can be anywhere from 4 to 30, and amps less than an amp to 5 amps. I don't think the Maplin units are available unused now, but CSE units are : https://www.circuitspecialists.eu/po...er-supplies/sw itch-mode-dc-bench-power-supply-adjustable-0-30v-0-5a-csi-3005sm/ Highly recommended. 10amp unit also available. Had a look as I want one too. It doesn't give any clue whether the adjustable current limit shows what it's set to or whether it's adjusted blind. I therefore expect it's the latter. Also beware the 0.2v ripple spec! Also zero info on meter accuracy. NT |
30V, 5-10A bench PSU recommendations?
On Tue, 15 Sep 2020 17:16:12 +0100, Graeme
wrote: In message , T i m writes On Tue, 15 Sep 2020 15:31:23 +0100, Graeme wrote: Highly recommended. That's the sort of thing I was hoping for, thanks. ;-) Tim, should you ever see an advert for a vintage train show, almost any display running 0 gauge or larger will be using Maplin or CSE units. I belong to various groups and hear nothing but praise for them, and use them myself. I think that does usually suggest they have found a good solution. ;-) There are others, designed for the job, that are just not up to it, particularly all day events, to the extent that people build frames with cooling fans to prevent overheating and cut out. Oh. ;-( No such problems reported with the Maplin/CSE units. Similar with RC racing car gear. You often see all sorts of gear at the beginning of a season but they gradually refine towards just a few models towards the end. I have also found CSE to be approachable and helpful, should the need arise. That was another question so thanks. ;-) OOI, do we think that the models shown on the CSE site are in any way different to those (exact looking) sold via the likes of eBay or Amazon etc? Not that CSE's prices aren't competitive etc? Cheers, T i m |
30V, 5-10A bench PSU recommendations?
On Tue, 15 Sep 2020 17:36:45 +0100, John Bryan
wrote: snip https://www.circuitspecialists.eu/po...er-supplies/sw itch-mode-dc-bench-power-supply-adjustable-0-30v-0-5a-csi-3005sm/ Highly recommended. 10amp unit also available. I have and use the CSI 3005T 30volt 5amp version Definitely recommended, it charged my car battery no probs. Excellent, thanks for the feedback and another vote for CSI. Did you go for the linear one for a specific reason may I ask John and if so, what OOI? Cheers, T i m |
30V, 5-10A bench PSU recommendations?
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30V, 5-10A bench PSU recommendations?
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30V, 5-10A bench PSU recommendations?
In message
T i m wrote: On Tue, 15 Sep 2020 17:36:45 +0100, John Bryan wrote: snip https://www.circuitspecialists.eu/po...er-supplies/sw itch-mode-dc-bench-power-supply-adjustable-0-30v-0-5a-csi-3005sm/ Highly recommended. 10amp unit also available. I have and use the CSI 3005T 30volt 5amp version Definitely recommended, it charged my car battery no probs. Excellent, thanks for the feedback and another vote for CSI. Did you go for the linear one for a specific reason may I ask John and if so, what OOI? Cheers, T i m No I wanted one where the current limit was fully adjustable, which on my model it is 0.001A to the max of 5.200A. the adjustment of voltage or current is achieved by pressing in the control knob to select the decade 10V.1V.0.1V,0.01V and turning the encoder shaft to to desired value. Current setting likewise but 1A,0.1A,0.01A and 0.001A units. -- John Bryan |
30V, 5-10A bench PSU recommendations?
On Tuesday, 15 September 2020 20:03:22 UTC+1, Dave Liquorice wrote:
On Tue, 15 Sep 2020 11:25:00 -0700 (PDT), tabbypurr wrote: Had a look as I want one too. It doesn't give any clue whether the adjustable current limit shows what it's set to or whether it's adjusted blind. I therefore expect it's the latter. There is a link to download the manual. Which doesn't tell you anything about how to operate it! Like how to set it to CV or CC mode, etc correct, though I would not expct there to be any separate CV or CC modes. With bench psus one simply sets the 2 limits. Also beware the 0.2v ripple spec! And being SMPSU "ripple" at few 10's of kHz? Doesn't bode well for how much RFI it chucks out. 0.2v of ripple is terrible for a bench psu. It seriously compromises what it can be used for. It does not lead me to conclude this is a competent unit. Also zero info on meter accuracy. I can see 3 digits A nd V "LCD +/- 1% +2 Digits". So upto 30.0v +/- 1% is 0.3v and 2 more digits is +/- a total of 0.5v. That's terrible. No good for me anyway. Good enough to run motors, but not as a multipurpose bench psu. NT |
30V, 5-10A bench PSU recommendations?
On Tuesday, 15 September 2020 20:56:16 UTC+1, T i m wrote:
On Tue, 15 Sep 2020 11:25:00 -0700 (PDT), tabbypurr wrote: snip https://www.circuitspecialists.eu/po...er-supplies/sw itch-mode-dc-bench-power-supply-adjustable-0-30v-0-5a-csi-3005sm/ Highly recommended. 10amp unit also available. Had a look as I want one too. It doesn't give any clue whether the adjustable current limit shows what it's set to or whether it's adjusted blind. I therefore expect it's the latter. By shorting the output out and then adjusting it? Is that what you mean by 'blind' or did you mean more 'on the fly'? Also beware the 0.2v ripple spec! What would that affect, ITRW and is it only likely (to be that high a value) to be at full load? Also zero info on meter accuracy. It's a 50 quid PSU. ;-) Cheers, T i m Quite. Even rock bottom £2 multimeters have specs. No specs makes the readings fairly meaningless. NT |
30V, 5-10A bench PSU recommendations?
On Tue, 15 Sep 2020 21:39:56 +0100, John Bryan
wrote: snip Did you go for the linear one for a specific reason may I ask John and if so, what OOI? No I wanted one where the current limit was fully adjustable, which on my model it is 0.001A to the max of 5.200A. So that was a 'yes' then, the current limit thing. Bit isn't that available on most 'current limiting' PSU's, even if they aren't so easy to apply (without shorting the output) or as accurate to set? I think most people use the current limit as a fuse or to limit the current for charging a car battery, where I don't think you need so much accuracy etc? It could be important when charging a very small battery etc. the adjustment of voltage or current is achieved by pressing in the control knob to select the decade 10V.1V.0.1V,0.01V and turning the encoder shaft to to desired value. Current setting likewise but 1A,0.1A,0.01A and 0.001A units. I checked out the PSU you have on Youtube and saw that in action and I was wondering how easy / fast it was to use in practice, compared with a straight linear knob etc (the only type I've used). If I use my Weir linear PSU as an example and charging a car battery. If the battery was a reasonable size then I'd just wind the current to max (assuming a 5A PSU), set the voltage to maybe 14V and connect up. If it was as smaller capacity battery (say off a motorbike) I might want to limit the current to 1A then I'd just turn the current knob up or down till it reads 1A. If it's already fully charged it may only take 1A (at 14V) for a few seconds in any case. An example of where the selection method of the PSU you have was shown on the Youtube video was where he set a very fine current limit to drive a LED, saves having to bother with a series resistor etc. I guess it might all boil down to how accurately you want to control the voltage and current and how often you are changing it (along with any other characteristics etc). My Weir PSUs have a single analogue meter on the front (albeit quite a big one) that you switch between volts and amps (triple reading scale as it can go 0-15V and 0-30V, plus amps etc) and I've found it sufficient for most of the stuff I've used it for so far. If I want more voltage accuracy I just stick a DMM on the thing I'm powering. The control knobs feel like they are wire would so probably quite expensive. I just prefer the digital display and am not sure I need to go down to that level of accuracy .01 V/A? That's for bringing it to my attention though and I will consider it further. ;-) Cheers, T i m |
30V, 5-10A bench PSU recommendations?
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30V, 5-10A bench PSU recommendations?
In message , T i m
writes OOI, do we think that the models shown on the CSE site are in any way different to those (exact looking) sold via the likes of eBay or Amazon etc? Not that CSE's prices aren't competitive etc? I think they are identical, although I don't have two units from different sources side by side to compare. Speaking to friends, some have purchased via Amazon or eBay and some (like me) direct from CSE, and all seem the same. -- Graeme |
30V, 5-10A bench PSU recommendations?
On Wed, 16 Sep 2020 07:29:33 +0100, Graeme
wrote: In message , T i m writes OOI, do we think that the models shown on the CSE site are in any way different to those (exact looking) sold via the likes of eBay or Amazon etc? Not that CSE's prices aren't competitive etc? I think they are identical, although I don't have two units from different sources side by side to compare. Speaking to friends, some have purchased via Amazon or eBay and some (like me) direct from CSE, and all seem the same. Thanks. After looking around and starting to get distracted by feature creep, I think I'm now resigned to go for the same as you and yer MR friends and go for the SM 30/5 jobby, partly because of the price (bang for buck), partly because your usage would be similar to mine (running things that aren't 'fussy' about voltage), ease of voltage adjustment and the compact size and light weight. The strange thing is that with a digital display you can be inclined to try to set the voltage exactly, say 12.00V when in many cases it wouldn't actually matter if it was 10 or 15 (as you are driving a voltage regulator in the first place). When I had the analogue displayed meter you just turned it to 'about' 12V and you were happy to leave it at that (very fast). I'm comparing that with the 4 digit analogue PSU with the encoder style digit-by-digit adjustment and just wondering if that might become a bit tiresome in use? Like if you want to go from 12 to 5V (I believe you have to): Press the voltage knob Turn it to select the units field (2) Press the knob again to select that field Turn it up to 5, (you now have 15V) Press the knob again to enter that value Turn it to select the 10's field (1) Press the knob again to select that field Turn it from 1 to 0 (now saying 5V) Not sure if you have to press it to select 0 or that it times out to 0? It's similar to setting some clocks. On the simpler linear adjustment versions and assuming the 'Fine' control knob is set in the middle of it's range. Turn the 'Coarse' voltage knob down from 12 to 5V, or as near as you can get with that control. If required, turn the 'Fine' voltage control to get a more accurate value. Cheers, T i m |
30V, 5-10A bench PSU recommendations?
In article ,
T i m wrote: I have a couple of linear PSU's (Weir, both 30V-2A, 15V-4A) but they are both old and are now non-functional / iffy and I was considering something newer, lighter, smaller and with twin digital displays (on the Weir's you have to switch between displaying V and A). There are loads over the normal suppliers but I wondered if anyone here had got something reasonably recently that they could recommend? It's for general use, (temporarily) powering 5/12V things, charging the odd battery and the like. A 10A capacity might mean it can batter handle a 5A output, quieter the better (some use small heatsinks and small fans) and ideally under say £100? I did look at kits (good to know you have the cct diagram) but that's probably not best done with a SMPSU and linear stuff also seems to require large heatsinks and heavy switching devices, all taking extra time to source/ build (unless a complete kit with case / hardware etc). I bought one from CPC some time ago. Twin unit, and does +/- rails at the push of a switch. Shows voltage and current from both at all times - 4 displays. Badged Circuit Specialists EU. Been very pleased with it. It does 0-50v so useful for testing power amp PCBs. It's neither small or light, though. -- *Despite the cost of living, have you noticed how it remains so popular?* Dave Plowman London SW To e-mail, change noise into sound. |
30V, 5-10A bench PSU recommendations?
In message , T i m
writes Turn the 'Coarse' voltage knob down from 12 to 5V, or as near as you can get with that control. If required, turn the 'Fine' voltage control to get a more accurate value. For my fairly basic use, I just leave both the fine controls and the amps at maximum, and use the coarse volts knob for control. The huge advantage is the digital readout which shows both volts and amps simultaneously, which is important for older motors. Just one example is pre war permanent magnet motors. The magnets tend to degrade over time, and consume more and more amps for the same performance, which leads to overheating and damage to motor windings. Watching amps consumed, and knowing the usual usage, is therefore important. -- Graeme |
30V, 5-10A bench PSU recommendations?
On Wed, 16 Sep 2020 11:09:47 +0100, Graeme
wrote: In message , T i m writes Turn the 'Coarse' voltage knob down from 12 to 5V, or as near as you can get with that control. If required, turn the 'Fine' voltage control to get a more accurate value. For my fairly basic use, I just leave both the fine controls and the amps at maximum, and use the coarse volts knob for control. Ah, that makes sense for the current (compared with leaving the fine current control in the middle), as it's a 'upper limit' and assuming you may need the full output etc. The huge advantage is the digital readout which shows both volts and amps simultaneously, which is important for older motors. Understood. That said, if I was doing that same job with my Weir PSU's with a single meter is I would set the voltage to something suitable, say 12V and then switch it over to current and could then watch the meter. Only if I reached full current would the voltage drop. Just one example is pre war permanent magnet motors. The magnets tend to degrade over time, and consume more and more amps for the same performance, which leads to overheating and damage to motor windings. Ahh. Watching amps consumed, and knowing the usual usage, is therefore important. Understood. I was doing the exact same thing when testing the Arduino based MR automated project with BIL [1]. We were both amazed at the differences in current pulled by his older and newer locos. Because there was no speed feedback in the project and the vast range of speeds resulting from said motor efficiencies, rather than going for the choice of running 'any' of his numerous locos, we selected a sub-set that all had similar power requirements. I can't think of any role where the noise from the PSU would be an issue to me or the controls too coarse. (And I have used what looks outwardly to be an identical model for a range of power and electronic things and found it fine). Cheers, T i m [1] I actually still have our MR automation test rig here. 4m of straight track with a bypass section in the middle. 4 digital IR reflective sensors positioned by the track near the ends and a diode connected 'dead' section each end of the track to prevent overruns. Loco, pulls away from end (with inertia) to max speed (adjustable with pot) to the 1st remote sensor then slows (with inertia) to a creep speed to the second sensor when it stops. The two points are set (using bridge drivers and a cap) and loco drives back the other way and round the bypass and back onto the main line, to the remote sensors. And it actually works. ;-) |
30V, 5-10A bench PSU recommendations?
Well when you say they are dead, its probably just capacitors, unless they
have been abused of course. My main problem with modern supplies are that they are switch mode. Firstly unless very well designed they produce massis of interference both down the mains, and radiating, and often there is a residue actual on the DC as well. I'd be tempted to visit somewhere who sells to Ham radio people, like Martin Lynch or Radioworld, or there are several others, as they are more likely to know of gotchas on individual supplies than than your average Ebay cheap Chinese box shifter. Brian -- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "T i m" wrote in message ... I have a couple of linear PSU's (Weir, both 30V-2A, 15V-4A) but they are both old and are now non-functional / iffy and I was considering something newer, lighter, smaller and with twin digital displays (on the Weir's you have to switch between displaying V and A). There are loads over the normal suppliers but I wondered if anyone here had got something reasonably recently that they could recommend? It's for general use, (temporarily) powering 5/12V things, charging the odd battery and the like. A 10A capacity might mean it can batter handle a 5A output, quieter the better (some use small heatsinks and small fans) and ideally under say £100? I did look at kits (good to know you have the cct diagram) but that's probably not best done with a SMPSU and linear stuff also seems to require large heatsinks and heavy switching devices, all taking extra time to source/ build (unless a complete kit with case / hardware etc). Cheers, T i m |
30V, 5-10A bench PSU recommendations?
On Wed, 16 Sep 2020 11:02:51 +0100, "Dave Plowman (News)"
wrote: snip I bought one from CPC some time ago. Twin unit, and does +/- rails at the push of a switch. Shows voltage and current from both at all times - 4 displays. Are the controls linear or push, encode etc? Badged Circuit Specialists EU. They seem to be pretty popular. ;-) Been very pleased with it. It does 0-50v so useful for testing power amp PCBs. I was torn re getting something with a 50V output (and at least 3A) but think the prices start creeping up. It's neither small or light, though. That's not a dealbreaker, if it ticks enough of the other boxes (price, speed / ease of use, reliability etc). Cheers, T i m |
30V, 5-10A bench PSU recommendations?
On Wed, 16 Sep 2020 12:04:42 +0100, "Brian Gaff \(Sofa\)"
wrote: Well when you say they are dead, its probably just capacitors, unless they have been abused of course. I think one is still working but not to full spec (it's been a while since I've used it / them). My main problem with modern supplies are that they are switch mode. Firstly unless very well designed they produce massis of interference both down the mains, and radiating, and often there is a residue actual on the DC as well. Ok, not sure that would affect a battery or model train. ;-) I'd be tempted to visit somewhere who sells to Ham radio people, like Martin Lynch or Radioworld, or there are several others, as they are more likely to know of gotchas on individual supplies than than your average Ebay cheap Chinese box shifter. But may well be more expensive.? ;-( I still have my 10A 13.8V linear 'Shack' PSU, a smaller adjustable SMPSU 5-15V, 0-15A (current limiting) RC usage PSU and in the loft, a *very* big and heavy 10A bench PSU that died (can't remember the voltage range). It's just that apart from the RC supply, none of the others are working fully and whilst I can charge 12V batteries with the RC PSU, it would have been handy to have 24V's worth of battery charging (mobility scooters) and even higher voltages for a two wheeler scooter. Cheers, T i m |
30V, 5-10A bench PSU recommendations?
In article ,
T i m wrote: On Wed, 16 Sep 2020 11:02:51 +0100, "Dave Plowman (News)" wrote: snip I bought one from CPC some time ago. Twin unit, and does +/- rails at the push of a switch. Shows voltage and current from both at all times - 4 displays. Are the controls linear or push, encode etc? Just knobs. ;-) Four which work independently when the two PS are seperate, or just two of them when ganged. Badged Circuit Specialists EU. They seem to be pretty popular. ;-) Been very pleased with it. It does 0-50v so useful for testing power amp PCBs. I was torn re getting something with a 50V output (and at least 3A) but think the prices start creeping up. It's neither small or light, though. That's not a dealbreaker, if it ticks enough of the other boxes (price, speed / ease of use, reliability etc). It seems to do everything I want and hasn't annoyed me in any way. Which is saying something. I'm sure a SMPS one could be smaller, but I've built mine in on the side of the workbench, so not taking up usable space. A bench top one would get in the way at one point or another. Cheers, T i m -- *If horrific means to make horrible, does terrific mean to make terrible? Dave Plowman London SW To e-mail, change noise into sound. |
30V, 5-10A bench PSU recommendations?
In message
T i m wrote: On Tue, 15 Sep 2020 21:39:56 +0100, John Bryan wrote: snip Did you go for the linear one for a specific reason may I ask John and if so, what OOI? No I wanted one where the current limit was fully adjustable, which on my model it is 0.001A to the max of 5.200A. So that was a 'yes' then, the current limit thing. Bit isn't that available on most 'current limiting' PSU's, even if they aren't so easy to apply (without shorting the output) or as accurate to set? I think most people use the current limit as a fuse or to limit the current for charging a car battery, where I don't think you need so much accuracy etc? It could be important when charging a very small battery etc. the adjustment of voltage or current is achieved by pressing in the control knob to select the decade 10V.1V.0.1V,0.01V and turning the encoder shaft to to desired value. Current setting likewise but 1A,0.1A,0.01A and 0.001A units. I checked out the PSU you have on Youtube and saw that in action and I was wondering how easy / fast it was to use in practice, compared with a straight linear knob etc (the only type I've used). If I use my Weir linear PSU as an example and charging a car battery. If the battery was a reasonable size then I'd just wind the current to max (assuming a 5A PSU), set the voltage to maybe 14V and connect up. If it was as smaller capacity battery (say off a motorbike) I might want to limit the current to 1A then I'd just turn the current knob up or down till it reads 1A. If it's already fully charged it may only take 1A (at 14V) for a few seconds in any case. An example of where the selection method of the PSU you have was shown on the Youtube video was where he set a very fine current limit to drive a LED, saves having to bother with a series resistor etc. I guess it might all boil down to how accurately you want to control the voltage and current and how often you are changing it (along with any other characteristics etc). My Weir PSUs have a single analogue meter on the front (albeit quite a big one) that you switch between volts and amps (triple reading scale as it can go 0-15V and 0-30V, plus amps etc) and I've found it sufficient for most of the stuff I've used it for so far. If I want more voltage accuracy I just stick a DMM on the thing I'm powering. The control knobs feel like they are wire would so probably quite expensive. I just prefer the digital display and am not sure I need to go down to that level of accuracy .01 V/A? That's for bringing it to my attention though and I will consider it further. ;-) Cheers, T i m I did not choose a linear power supply for any particular reason but as I said the current limiting was more important for re-charging Ni-Cad batteries in a couple of tools I have. Their chargers having died a few years ago. Both voltage and current setting are achieved using an encoder. When you press the knob in the range digit flashes and whilst it remains in that mode turning the knob adjusts the displayed value up or down. Say you repeatedly pressed to set the 10mV range you can adjust the voltage up or down throughout the output range 0 to 30 volts. It does take quite a few revolutions to get the output up to 30volts from zero though. -- John Bryan |
30V, 5-10A bench PSU recommendations?
On Wed, 16 Sep 2020 18:24:53 +0100, John Bryan
wrote: snip I did not choose a linear power supply for any particular reason but as I said the current limiting was more important for re-charging Ni-Cad batteries in a couple of tools I have. OOI, don't most bench chargers have adjustable current limit? Their chargers having died a few years ago. Like they do. ;-( Both voltage and current setting are achieved using an encoder. When you press the knob in the range digit flashes and whilst it remains in that mode turning the knob adjusts the displayed value up or down. Understood. Say you repeatedly pressed to set the 10mV range you can adjust the voltage up or down throughout the output range 0 to 30 volts. It does take quite a few revolutions to get the output up to 30volts from zero though. Ah, that's interesting and thanks for the clarification. So if you set it on the units field you could wind it down from say 12 to 5 volts just by turning the knob (eg, it wouldn't just go from 12 to 10 and up to 19 and back down etc)? If that was the case and based on the fact that most people would set the volts in 'whole unit' increments, that would make it much more useable IMHO). Similar thing could happen with the current limit in that you could have it on the .1 range and still have reasonable speed and granularity? Do you have to leave it to 'time out' on the individual digit for the above to happen (eg, to stop it just cycling round that field or does it never do that)? Cheers, T i m |
30V, 5-10A bench PSU recommendations?
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T i m wrote: On Wed, 16 Sep 2020 18:24:53 +0100, John Bryan wrote: snip I did not choose a linear power supply for any particular reason but as I said the current limiting was more important for re-charging Ni-Cad batteries in a couple of tools I have. OOI, don't most bench chargers have adjustable current limit? Their chargers having died a few years ago. Like they do. ;-( Both voltage and current setting are achieved using an encoder. When you press the knob in the range digit flashes and whilst it remains in that mode turning the knob adjusts the displayed value up or down. Understood. Say you repeatedly pressed to set the 10mV range you can adjust the voltage up or down throughout the output range 0 to 30 volts. It does take quite a few revolutions to get the output up to 30volts from zero though. Ah, that's interesting and thanks for the clarification. So if you set it on the units field you could wind it down from say 12 to 5 volts just by turning the knob (eg, it wouldn't just go from 12 to 10 and up to 19 and back down etc)? The display would go from the initial 12, 11, 10, 9, 8, 7, 6, then 5. Conversely going up 12, 13, 14,.....up to 30. If that was the case and based on the fact that most people would set the volts in 'whole unit' increments, that would make it much more useable IMHO). Similar thing could happen with the current limit in that you could have it on the .1 range and still have reasonable speed and granularity? Yes and obviously on the 1 amp setting you only have five steps and on the 100mA setting 50steps. Do you have to leave it to 'time out' on the individual digit for the above to happen (eg, to stop it just cycling round that field or does it never do that)? Cheers, T i m Yes you have to leave it to time out but it is only for 4-5 seconds. The output display when setting mode increments/decrements the whole of the voltage or current display. So in your example when in the 100mV field, turning the control anti-clockwise the display would show 11.90, then 11.80 and so on down to 5.10 then 5.00. Left for 5 seconds the display stops flashing and the output is now set at 5.00 volts. The display does not cycle round. When at the minimum or maximum is gives a bleep as a warning. The control can still be turned being but an encoder does not change the output. **** -- John Bryan |
30V, 5-10A bench PSU recommendations?
On Wed, 16 Sep 2020 23:50:17 +0100, John Bryan
wrote: snip So if you set it on the units field you could wind it down from say 12 to 5 volts just by turning the knob (eg, it wouldn't just go from 12 to 10 and up to 19 and back down etc)? The display would go from the initial 12, 11, 10, 9, 8, 7, 6, then 5. Conversely going up 12, 13, 14,.....up to 30. Understood, thanks (once out of 'setting' mode?) If that was the case and based on the fact that most people would set the volts in 'whole unit' increments, that would make it much more useable IMHO). Similar thing could happen with the current limit in that you could have it on the .1 range and still have reasonable speed and granularity? Yes and obviously on the 1 amp setting you only have five steps and on the 100mA setting 50steps. Check. Do you have to leave it to 'time out' on the individual digit for the above to happen (eg, to stop it just cycling round that field or does it never do that)? Yes you have to leave it to time out but it is only for 4-5 seconds. Check. The output display when setting mode increments/decrements the whole of the voltage or current display. Is there any prior indication on what field you will be on when you press the encoder again John or is it 'suck it and see' (press it and see what flashes)? So in your example when in the 100mV field, turning the control anti-clockwise the display would show 11.90, then 11.80 and so on down to 5.10 then 5.00. Check. Left for 5 seconds the display stops flashing and the output is now set at 5.00 volts. Ah, so, what happens to the output voltage between selections? Does it stay at the last setting, follow the changes or disconnect till the new voltage is selected etc? The display does not cycle round. Noted (and that might be just as well, depending on the output status during changes etc). When at the minimum or maximum is gives a bleep as a warning. Ok. The control can still be turned being but an encoder does not change the output. Understood. Cheers, T i m |
30V, 5-10A bench PSU recommendations?
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T i m wrote: On Wed, 16 Sep 2020 23:50:17 +0100, John Bryan wrote: snip So if you set it on the units field you could wind it down from say 12 to 5 volts just by turning the knob (eg, it wouldn't just go from 12 to 10 and up to 19 and back down etc)? The display would go from the initial 12, 11, 10, 9, 8, 7, 6, then 5. Conversely going up 12, 13, 14,.....up to 30. Understood, thanks (once out of 'setting' mode?) If that was the case and based on the fact that most people would set the volts in 'whole unit' increments, that would make it much more useable IMHO). Similar thing could happen with the current limit in that you could have it on the .1 range and still have reasonable speed and granularity? Yes and obviously on the 1 amp setting you only have five steps and on the 100mA setting 50steps. Check. Do you have to leave it to 'time out' on the individual digit for the above to happen (eg, to stop it just cycling round that field or does it never do that)? Yes you have to leave it to time out but it is only for 4-5 seconds. Check. The output display when setting mode increments/decrements the whole of the voltage or current display. Is there any prior indication on what field you will be on when you press the encoder again John or is it 'suck it and see' (press it and see what flashes)? No. I have just tested that and from power on the most significant field flashes in either voltage or current setting mode. The least significant field is only four quick pushes away. If you miss it, just keep pressing as the display cycles through most to least field and then back again least to most field, which seems a bit wierd to me! I have never given this a thought as it seemed to be intuitive to just repeatedly press the control to get to the one needed. So in your example when in the 100mV field, turning the control anti-clockwise the display would show 11.90, then 11.80 and so on down to 5.10 then 5.00. Check. Left for 5 seconds the display stops flashing and the output is now set at 5.00 volts. Ah, so, what happens to the output voltage between selections? Does it stay at the last setting, follow the changes or disconnect till the new voltage is selected etc? The display does not cycle round. Noted (and that might be just as well, depending on the output status during changes etc). When at the minimum or maximum is gives a bleep as a warning. Ok. The control can still be turned being but an encoder does not change the output. Understood. Cheers, T i m -- John Bryan |
30V, 5-10A bench PSU recommendations?
On Thu, 17 Sep 2020 19:21:06 +0100, John Bryan
wrote: snip Is there any prior indication on what field you will be on when you press the encoder again John or is it 'suck it and see' (press it and see what flashes)? No. I have just tested that and from power on the most significant field flashes in either voltage or current setting mode. Erm, so with current that would equate to whole amps and with voltage, 10's of volts or just volt units (given it goes to 30V)? The least significant field is only four quick pushes away. So that would be from 10's of volts? If you miss it, just keep pressing as the display cycles through most to least field and then back again least to most field, which seems a bit wierd to me! And me ...? I have never given this a thought as it seemed to be intuitive to just repeatedly press the control to get to the one needed. Yeah, I'm sure if it was in front of me I'd work it out easily but I'm trying to ascertain how time consuming it might be if you were changing stuff regularly and didn't need the accuracy / granularity. So can I check on this please John. From power on, both voltage and current flash the MSB and assuming you do nothing, will stop flashing in ~5 seconds and will return to the last used values I understand (say 12.000V, (or would it be only 12.00V?) and 3.000A current limit) .... .... (Recap) If you then turn either knob then you will change values in 10's of volts (or just volts?) and whole amps? If you want to then say set it to 5.004V (for some reason g) you first (just) turn the voltage knob (because it defaults to units?) anticlock till it reads 5 in the units field then press the knob three times and then ... (while it's still flashing or otherwise) turn it to 4? Cheers, T i m |
30V, 5-10A bench PSU recommendations?
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T i m wrote: On Thu, 17 Sep 2020 19:21:06 +0100, John Bryan wrote: snip Is there any prior indication on what field you will be on when you press the encoder again John or is it 'suck it and see' (press it and see what flashes)? No. I have just tested that and from power on the most significant field flashes in either voltage or current setting mode. Erm, so with current that would equate to whole amps and with voltage, 10's of volts or just volt units (given it goes to 30V)? When switched on the displays show the last settings of voltage and current, after 5 seconds the displays indicate the measureded load requirements. The least significant field is only four quick pushes away. So that would be from 10's of volts? Yes If you miss it, just keep pressing as the display cycles through most to least field and then back again least to most field, which seems a bit wierd to me! And me ...? I have never given this a thought as it seemed to be intuitive to just repeatedly press the control to get to the one needed. Yeah, I'm sure if it was in front of me I'd work it out easily but I'm trying to ascertain how time consuming it might be if you were changing stuff regularly and didn't need the accuracy / granularity. It does seem a little complicated but within a few minutes it will become obvious as to the setting up. So can I check on this please John. From power on, both voltage and current flash the MSB and assuming you do nothing, will stop flashing in ~5 seconds and will return to the last used values I understand (say 12.000V, (or would it be only 12.00V?) and 3.000A current limit) ... No. The displays show the last settings used and then revert to the measured values. To change them you press the relevant control and set your requirement. ... (Recap) If you then turn either knob then you will change values in 10's of volts (or just volts?) and whole amps? Yes but only after you have pressed the control knob. If you want to then say set it to 5.004V (for some reason g) you first (just) turn the voltage knob (because it defaults to units?) anticlock till it reads 5 in the units field then press the knob three times and then ... (while it's still flashing or otherwise) turn it to 4? You cannot set it to 05.004V To set it to 5.04V - it only has a 4 digit display so can only get to 10mV Power on Press the voltage control knob The 10V digit will flash - Turn down to zero Press the voltage control knob again. the unity volts flash Rotate control up/down to set 5V Press control knob twice to get to 10mV and rotate to set to 05.04V Hope this a little clearer Current setting is likewise. Cheers, T i m -- John Bryan |
30V, 5-10A bench PSU recommendations?
On Fri, 18 Sep 2020 00:17:23 +0100, John Bryan
wrote: snip Erm, so with current that would equate to whole amps and with voltage, 10's of volts or just volt units (given it goes to 30V)? When switched on the displays show the last settings of voltage and current, after 5 seconds the displays indicate the measureded load requirements. The least significant field is only four quick pushes away. So that would be from 10's of volts? Yes Ok. snip So can I check on this please John. From power on, both voltage and current flash the MSB and assuming you do nothing, will stop flashing in ~5 seconds and will return to the last used values I understand (say 12.000V, (or would it be only 12.00V?) and 3.000A current limit) ... No. Oh? The displays show the last settings used Isn't that what I said or were you not saying no to that bit? and then revert to the measured values. Which in case of the voltage and assuming it's not already current limiting will be the same as the initial value and the current will be the actually current being drawn (not the limit)? But the point was it *will* be the last uses values, not some arbitrary values. To change them you press the relevant control and set your requirement. Yes, I get that bit. ;-) ... (Recap) If you then turn either knob then you will change values in 10's of volts (or just volts?) and whole amps? Yes but only after you have pressed the control knob. Eh? So the knobs don't work 'normally', only when in setting mode? Turn on. Display shows last used settings with the MSB flashing. Allow 10 seconds. Display show last voltage used and current amps drawn. Turn either knob and you do or don't change the values 'live' John? If you want to then say set it to 5.004V (for some reason g) you first (just) turn the voltage knob (because it defaults to units?) anticlock till it reads 5 in the units field then press the knob three times and then ... (while it's still flashing or otherwise) turn it to 4? You cannot set it to 05.004V To set it to 5.04V - it only has a 4 digit display so can only get to 10mV I wasn't sure if you regained that extra digit when only showing single volts rather than 10's of volts. Ok, that makes it clearer. Power on Press the voltage control knob The 10V digit will flash - Turn down to zero Press the voltage control knob again. the unity volts flash Rotate control up/down to set 5V Press control knob twice to get to 10mV and rotate to set to 05.04V Hope this a little clearer Yes, that's sorta how I thought it worked, but I am now confused re where you were saying that if you turn the voltage knob up or down either side of 10V you will see 10, 9, 8, 9, 10, 11,12 etc? Current setting is likewise. Let's try a recap (I will get this pinned down). ;-) 1) Switch on 2a) At switch on and for ~5 seconds ... display shows last used voltage and current limit values with the most significant field(s) flashing. So if it was set to 12.00V and 3.000A CL, the 1 (of the 12) and 3 are flashing. (I think I understand it to be this) or 2b) At switch on and for ~5 seconds ... display shows last used voltage and current limit values with the most significant field(s) flashing. So if it was set to 12.00V and 3.000A CL, the 12 and 3 are flashing. (not this?). 3) Leave for ~5 s and the PSU will provide the volts and current limit values displayed. 4) Press the voltage button once and because it defaults to the first (most significant) digit, that will flash, allowing you to set that field ONLY. eg, if you keep rotating it clockwise from 1 it will go to 2 then 3 (then stop doing anything as the max voltage is 30 (and I think you said it will beep)). Whilst it's still flashing, turning it anticlock will see the display going from 3, 2, 1 to 0 and another 'end of range' beep. Leave the knob for ~5s and that digit will stop flashing and that value will become the used value. 5) If you press the voltage knob again (once it's returned to steady) you will 'still' be at the most significant field (so say the 1 of 12V) so you will be in the same position as in 4). 6) If whilst the display is flashing, you press the knob a second time, the next (less significant) field will start to flash, so if it was reading 12V, it will now be the 2. Then rotating the knob clockwise will see the values going up to 9 (then beep ... or only beep once you try to go *past* 9?) and anticlockwise the value going back down to 0 (and then beep there or if you try to go past 0). 7) With the active voltage adjust units field left as the active one (so 2 of 12V), and ~5s have passed, rotating the voltage knob will increase or decrease the voltage in whole units up to 30 and down to zero. (?) 8) With the display flashing, repeatedly pressing the knob will see the flashing field move backwards and forwards between the two ends (like ''Kit' the car on Night Rider). ;-) Assuming I'm close now, I'm also interested to know at what point the voltage (/ current) actually changes? eg, is it as you select it or only when it's set? Also to confirm the knobs *can* be used live as I believe you have said previously across the full range and in whatever increments you have last set (1V, 0.1V, 0.00A etc). Thanks for your time John. Cheers, T i m |
30V, 5-10A bench PSU recommendations?
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T i m wrote: On Fri, 18 Sep 2020 00:17:23 +0100, John Bryan wrote: snip Erm, so with current that would equate to whole amps and with voltage, 10's of volts or just volt units (given it goes to 30V)? When switched on the displays show the last settings of voltage and current, after 5 seconds the displays indicate the measureded load requirements. The least significant field is only four quick pushes away. So that would be from 10's of volts? Yes Ok. snip So can I check on this please John. From power on, both voltage and current flash the MSB and assuming you do nothing, will stop flashing in ~5 seconds and will return to the last used values I understand (say 12.000V, (or would it be only 12.00V?) and 3.000A current limit) ... No. Oh? The displays show the last settings used Isn't that what I said or were you not saying no to that bit? When powered up both displays show the users last settings but do not flash. After a few seconds they display the supplied values. CV led lit assuming not in current limit mode. and then revert to the measured values. Which in case of the voltage and assuming it's not already current limiting will be the same as the initial value and the current will be the actually current being drawn (not the limit)? But the point was it *will* be the last uses values, not some arbitrary values. This is correct it will be the last user set values. I do not know how long it retains these values as I have never left it powered off more than few days. To change them you press the relevant control and set your requirement. Yes, I get that bit. ;-) ... (Recap) If you then turn either knob then you will change values in 10's of volts (or just volts?) and whole amps? Yes but only after you have pressed the control knob. Eh? So the knobs don't work 'normally', only when in setting mode? Turn on. Display shows last used settings with the MSB flashing. Allow 10 seconds. Display show last voltage used and current amps drawn. Turn either knob and you do or don't change the values 'live' John? If you want to then say set it to 5.004V (for some reason g) you first (just) turn the voltage knob (because it defaults to units?) anticlock till it reads 5 in the units field then press the knob three times and then ... (while it's still flashing or otherwise) turn it to 4? You cannot set it to 05.004V To set it to 5.04V - it only has a 4 digit display so can only get to 10mV I wasn't sure if you regained that extra digit when only showing single volts rather than 10's of volts. Ok, that makes it clearer. Power on Press the voltage control knob The 10V digit will flash - Turn down to zero Press the voltage control knob again. the unity volts flash Rotate control up/down to set 5V Press control knob twice to get to 10mV and rotate to set to 05.04V Hope this a little clearer Yes, that's sorta how I thought it worked, but I am now confused re where you were saying that if you turn the voltage knob up or down either side of 10V you will see 10, 9, 8, 9, 10, 11,12 etc? Current setting is likewise. Let's try a recap (I will get this pinned down). ;-) 1) Switch on 2a) At switch on and for ~5 seconds ... display shows last used voltage and current limit values with the most significant field(s) flashing. So if it was set to 12.00V and 3.000A CL, the 1 (of the 12) and 3 are flashing. (I think I understand it to be this) or 2b) At switch on and for ~5 seconds ... display shows last used voltage and current limit values with the most significant field(s) flashing. So if it was set to 12.00V and 3.000A CL, the 12 and 3 are flashing. (not this?). 3) Leave for ~5 s and the PSU will provide the volts and current limit values displayed. 4) Press the voltage button once and because it defaults to the first (most significant) digit, that will flash, allowing you to set that field ONLY. eg, if you keep rotating it clockwise from 1 it will go to 2 then 3 (then stop doing anything as the max voltage is 30 (and I think you said it will beep)). Whilst it's still flashing, turning it anticlock will see the display going from 3, 2, 1 to 0 and another 'end of range' beep. Leave the knob for ~5s and that digit will stop flashing and that value will become the used value. 5) If you press the voltage knob again (once it's returned to steady) you will 'still' be at the most significant field (so say the 1 of 12V) so you will be in the same position as in 4). 6) If whilst the display is flashing, you press the knob a second time, the next (less significant) field will start to flash, so if it was reading 12V, it will now be the 2. Then rotating the knob clockwise will see the values going up to 9 (then beep ... or only beep once you try to go *past* 9?) and anticlockwise the value going back down to 0 (and then beep there or if you try to go past 0). 7) With the active voltage adjust units field left as the active one (so 2 of 12V), and ~5s have passed, rotating the voltage knob will increase or decrease the voltage in whole units up to 30 and down to zero. (?) 8) With the display flashing, repeatedly pressing the knob will see the flashing field move backwards and forwards between the two ends (like ''Kit' the car on Night Rider). ;-) Assuming I'm close now, I'm also interested to know at what point the voltage (/ current) actually changes? eg, is it as you select it or only when it's set? Also to confirm the knobs *can* be used live as I believe you have said previously across the full range and in whatever increments you have last set (1V, 0.1V, 0.00A etc). Thanks for your time John. Cheers, T i m No problem you got me to try something I had never given a thought about i.e. the digit cycling. Hope this has been of help. -- John Bryan |
30V, 5-10A bench PSU recommendations?
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T i m wrote: On Fri, 18 Sep 2020 00:17:23 +0100, John Bryan wrote: snip Erm, so with current that would equate to whole amps and with voltage, 10's of volts or just volt units (given it goes to 30V)? When switched on the displays show the last settings of voltage and current, after 5 seconds the displays indicate the measureded load requirements. The least significant field is only four quick pushes away. So that would be from 10's of volts? Yes Ok. snip So can I check on this please John. From power on, both voltage and current flash the MSB and assuming you do nothing, will stop flashing in ~5 seconds and will return to the last used values I understand (say 12.000V, (or would it be only 12.00V?) and 3.000A current limit) ... No. Oh? The displays show the last settings used Isn't that what I said or were you not saying no to that bit? and then revert to the measured values. Which in case of the voltage and assuming it's not already current limiting will be the same as the initial value and the current will be the actually current being drawn (not the limit)? But the point was it *will* be the last uses values, not some arbitrary values. To change them you press the relevant control and set your requirement. Yes, I get that bit. ;-) ... (Recap) If you then turn either knob then you will change values in 10's of volts (or just volts?) and whole amps? Yes but only after you have pressed the control knob. Eh? So the knobs don't work 'normally', only when in setting mode? Oops missed this one Yes you can turn the knobs until the cows come home and it will not change anything. Only when the knob is pressed in and a digit is flashing. I presume pressing the knob signals the control circuit and enables the knob encoder to change something. Turn on. Display shows last used settings with the MSB flashing. Allow 10 seconds. Display show last voltage used and current amps drawn. Turn either knob and you do or don't change the values 'live' John? If you want to then say set it to 5.004V (for some reason g) you first (just) turn the voltage knob (because it defaults to units?) anticlock till it reads 5 in the units field then press the knob three times and then ... (while it's still flashing or otherwise) turn it to 4? You cannot set it to 05.004V To set it to 5.04V - it only has a 4 digit display so can only get to 10mV I wasn't sure if you regained that extra digit when only showing single volts rather than 10's of volts. Ok, that makes it clearer. Power on Press the voltage control knob The 10V digit will flash - Turn down to zero Press the voltage control knob again. the unity volts flash Rotate control up/down to set 5V Press control knob twice to get to 10mV and rotate to set to 05.04V Hope this a little clearer Yes, that's sorta how I thought it worked, but I am now confused re where you were saying that if you turn the voltage knob up or down either side of 10V you will see 10, 9, 8, 9, 10, 11,12 etc? Current setting is likewise. Let's try a recap (I will get this pinned down). ;-) 1) Switch on 2a) At switch on and for ~5 seconds ... display shows last used voltage and current limit values with the most significant field(s) flashing. So if it was set to 12.00V and 3.000A CL, the 1 (of the 12) and 3 are flashing. (I think I understand it to be this) or 2b) At switch on and for ~5 seconds ... display shows last used voltage and current limit values with the most significant field(s) flashing. So if it was set to 12.00V and 3.000A CL, the 12 and 3 are flashing. (not this?). 3) Leave for ~5 s and the PSU will provide the volts and current limit values displayed. 4) Press the voltage button once and because it defaults to the first (most significant) digit, that will flash, allowing you to set that field ONLY. eg, if you keep rotating it clockwise from 1 it will go to 2 then 3 (then stop doing anything as the max voltage is 30 (and I think you said it will beep)). Whilst it's still flashing, turning it anticlock will see the display going from 3, 2, 1 to 0 and another 'end of range' beep. Leave the knob for ~5s and that digit will stop flashing and that value will become the used value. 5) If you press the voltage knob again (once it's returned to steady) you will 'still' be at the most significant field (so say the 1 of 12V) so you will be in the same position as in 4). 6) If whilst the display is flashing, you press the knob a second time, the next (less significant) field will start to flash, so if it was reading 12V, it will now be the 2. Then rotating the knob clockwise will see the values going up to 9 (then beep ... or only beep once you try to go *past* 9?) and anticlockwise the value going back down to 0 (and then beep there or if you try to go past 0). 7) With the active voltage adjust units field left as the active one (so 2 of 12V), and ~5s have passed, rotating the voltage knob will increase or decrease the voltage in whole units up to 30 and down to zero. (?) 8) With the display flashing, repeatedly pressing the knob will see the flashing field move backwards and forwards between the two ends (like ''Kit' the car on Night Rider). ;-) Assuming I'm close now, I'm also interested to know at what point the voltage (/ current) actually changes? eg, is it as you select it or only when it's set? Also to confirm the knobs *can* be used live as I believe you have said previously across the full range and in whatever increments you have last set (1V, 0.1V, 0.00A etc). Thanks for your time John. Cheers, T i m -- John Bryan |
30V, 5-10A bench PSU recommendations?
On Fri, 18 Sep 2020 18:22:13 +0100, John Bryan
wrote: snip When powered up both displays show the users last settings but do not flash. Ah, sorry. After a few seconds they display the supplied values. CV led lit assuming not in current limit mode. Ok. and then revert to the measured values. Which in case of the voltage and assuming it's not already current limiting will be the same as the initial value and the current will be the actually current being drawn (not the limit)? But the point was it *will* be the last uses values, not some arbitrary values. This is correct it will be the last user set values. Ok good. I do not know how long it retains these values as I have never left it powered off more than few days. I guess if they were held in some sort of NV RAM it could be indefinitely. ;-) snip No problem you got me to try something I had never given a thought about i.e. the digit cycling. ;-) Hope this has been of help. Yeah, I think so John, thanks. ;-) Cheers, T i m |
30V, 5-10A bench PSU recommendations?
On Fri, 18 Sep 2020 18:26:25 +0100, John Bryan
wrote: snip Eh? So the knobs don't work 'normally', only when in setting mode? Oops missed this one Well, there were quite a few questions. ;-) Yes you can turn the knobs until the cows come home and it will not change anything. Only when the knob is pressed in and a digit is flashing. Ah, got it. I presume pressing the knob signals the control circuit and enables the knob encoder to change something. Yes, probably good if you were to nudge them round by mistake. [1] Cheers, T i m [1] Years ago I was having the physiotherapy on my back for a trapped nerve and had a session of electro therapy, electrodes suck on my back and hooked up to a machine causing my back muscles to contract and release at a couple of second intervals. Laying on my front, machine on a trolley by my head hands and me on my elbows, left to 'turn the voltage level up, as / when you can handle it' .. . She left me set on level 3 of 10 and I'd slowly got it up up about 5 when, as I'd just got my hand on the level knob my elbow slipped off the end of the bed and I span it round to 10! Now, whilst I could just about cope with the pain, I initially couldn't recover enough between bursts to get my hands back on the machine to turn it down (but after a few goes I did). Now, if you had to press the knob in fist, that wouldn't have happened. ;-( |
30V, 5-10A bench PSU recommendations?
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T i m wrote: On Fri, 18 Sep 2020 18:26:25 +0100, John Bryan wrote: snip Eh? So the knobs don't work 'normally', only when in setting mode? Oops missed this one Well, there were quite a few questions. ;-) Yes you can turn the knobs until the cows come home and it will not change anything. Only when the knob is pressed in and a digit is flashing. Ah, got it. I presume pressing the knob signals the control circuit and enables the knob encoder to change something. Yes, probably good if you were to nudge them round by mistake. [1] Cheers, T i m [1] Years ago I was having the physiotherapy on my back for a trapped nerve and had a session of electro therapy, electrodes suck on my back and hooked up to a machine causing my back muscles to contract and release at a couple of second intervals. Laying on my front, machine on a trolley by my head hands and me on my elbows, left to 'turn the voltage level up, as / when you can handle it' .. . She left me set on level 3 of 10 and I'd slowly got it up up about 5 when, as I'd just got my hand on the level knob my elbow slipped off the end of the bed and I span it round to 10! Now, whilst I could just about cope with the pain, I initially couldn't recover enough between bursts to get my hands back on the machine to turn it down (but after a few goes I did). Now, if you had to press the knob in fist, that wouldn't have happened. ;-( Would have thought this should have been a stepped switch to prevent just this. I take you survived this misfortune and are now worse for it. I felt for you when I read your recollection. I had to endure a bout of Physio terrorism and did ask to see their big book of 1001 Ways To Inflict Pain (available in hardback)... Ha Ha only joking -- John Bryan |
30V, 5-10A bench PSU recommendations?
On Sat, 19 Sep 2020 19:43:09 +0100, John Bryan
wrote: snip She left me set on level 3 of 10 and I'd slowly got it up up about 5 when, as I'd just got my hand on the level knob my elbow slipped off the end of the bed and I span it round to 10! Now, whilst I could just about cope with the pain, I initially couldn't recover enough between bursts to get my hands back on the machine to turn it down (but after a few goes I did). Now, if you had to press the knob in fist, that wouldn't have happened. ;-( Would have thought this should have been a stepped switch to prevent just this. It was actually weighted (like a HiFi volume knob), so once it started .... I take you survived this misfortune and are now worse for it. Yes. It was just *very* uncomfortable at the time (as in electro-induced muscular cramping) but it died went off pretty quickly. ;-) I felt for you when I read your recollection. Thanks. It was definitely 'a moment' I would have preferred not to experience but did make for a good story. I had to endure a bout of Physio terrorism and did ask to see their big book of 1001 Ways To Inflict Pain (available in hardback)... 'This will probably hurt you more than it hurts me ...' ;-) Ha Ha only joking ;-) I can't remember if the 'treatment' helped but I think I only had 2 or 3 sessions (BUPA). Cheers, T i m |
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