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

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

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.

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

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

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

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.

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

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

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

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

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

On Tue, 15 Sep 2020 11:25:00 -0700 (PDT), 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

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.

Also zero info on meter accuracy.

I can see
3 digits
A nd V "LCD +/- 1% +2 Digits".

--
Cheers
Dave.

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

used his keyboard to write :
Had a look as I want one too. It doesn't give any clue whetherer the
adjustable current limit shows what it's set to or whether it's adjusted
blind.

Yes, blind, but you can work around it by shorting the output and
gradually increasing the current limit to what you want.

On Tue, 15 Sep 2020 20:49:20 +0100, Harry Bloomfield, Esq.
wrote:

used his keyboard to write :
Had a look as I want one too. It doesn't give any clue whetherer the
adjustable current limit shows what it's set to or whether it's adjusted
blind.

Yes, blind, but you can work around it by shorting the output and
gradually increasing the current limit to what you want.

I'm still considering if to go for a 50V PSU or not (I have been
repairing a 36V Li-Ion eBike bike for a mate and that needs 42V to
charge it) but in the meantime seen someone makes an auto CC/CL
'upgrade' for some of the CSI (and clones) bench PSU's (to save you
having to short the output to set the current limit).

https://www.youtube.com/watch?v=ajfQF3cOm-E

https://www.youtube.com/watch?v=KCZl...rsjDXpKzB1PO1A

https://www.ianjohnston.com/index.ph...ode-kit-detail

Cheers, T i m

On Tue, 15 Sep 2020 11:25:00 -0700 (PDT), 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

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

On Tue, 15 Sep 2020 15:13:30 -0700 (PDT), wrote:

snip

Quite. Even rock bottom £2 multimeters have specs. No specs makes the readings fairly meaningless.

Depending on what you use the PSU for.

All my PSU's so far have been linear and with analogue displays and
controls and so the setting accuracy was really down to the analogue
meter and the granularity of the control knobs.

Two Weirs are built like an old skool radio with lots or wires and a
fairly large PCB and given most of the stuff on there is likely to be
good (or easily replaced), I was wondering if I couldn't take the most
faulty one and 'upgrade' it with an LM338 or similar?

I could replace the analogue meter with two digital ones (or a dual
one) but I could stick with the analogue meters to start with as
that's less to do.

The only thing is it's currently able to be split rail or 0-30 so I'd
probably lose the spilt bit (not sure I've ever used it).

Ideally I'd like a kit PCB with all the components on that aren't
already in the Weir and start from that. At least I could fault find
it if / when it goes wrong. ;-)

I have seen one that suggests the LM338 can be 0-30V and 5A so I could
limit the current to 4A to match the existing meter and allow it to
run cooler (it has a large passive heatsink across the back).

Cheers, T i m

p.s. I think I'll still go for one of the basic SM PSU's and I'm sure
it would be fine for most my needs and I've used one before.

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.

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

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.

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

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