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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Battery doorbell local repeater?
Hi all,
I appreciate this is a design rather than repair question but I appreciate there are some very skilled people here. ;-) Scenario. I have a wired bellpush on the front door (frame) that runs to a battery 'Ding-dong' type solenoid chime further back in the house, the idea being that 'we' can hear it anywhere in the house (we can) and also in the back garden if we are lucky (we also sometimes can). The 'problem' is that you can't generally hear it outside the DG front door and so couriers often ring the bell *and* repeatedly bang on the glass door or flap the letterbox flap, sometimes winding the dog up thinking it's an aggressor. ;-) So, I was just wondering ... if I had some sort of small electro-mechanical buzzer (possibly to also give physical feedback), just inside the front door (on the inside door frame, directly behind the bell push for best feedback and easy wiring) that you could hear from the outside, that might give anyone on the outside some level of positive feedback that the bell had worked (hopefully anyway)? So, I am limited to 6V DC via the 4 x C cells (currently Ni-Mh's so only 4.8V) and don't want to add any real parasitic drain, especially if I go back to alkaline cells to get the full 6V. So I was thinking (but am no electronics design engineer) of some form of diode fed - series resistance cap that could be charged by the 6V supply seen at the back of the bell push that could then be discharged via a low voltage buzzer when the button is pressed (even if only once and for ~1s) ... and would then reset ready for another press say in 30 seconds time (given the original doorbell will continue to work as normal etc). Things I believe are relevant ... you would need a cap big enough to provide as good a quality level of power long enough to give a significant 'buzz' to be heard. The charging resistance would need to be low enough to not cause the bell to hang on the 'Ding', once the button was released (the chime solenoid just returns under spring power when no current flows but might be 'held' by a much lower current (so no proper 'dong'). I didn't know if the buzzer trigger could / should be done by a self latching circuit of some sort or if one should use a zener to manage the voltage allowing a better release action? I am aware of all the other options like using a mains transformer or wireless repeater / converters, I was really only interested in seeing if such a direct repeater could be practical? ;-) Cheers, T i m p.s. Yesterday I successfully repaired one of those plug in wirelessly charged PIR / power cut type torch / lights. It was a resistor that burns out in the 240V base and is replaced (sometimes along with a transistor and cap) and normally get's them working again. Unfortunately the Lithium (14430) battery in the torch part had gone very flat (sub 1V) so I have a replacement on the way. |
#2
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Battery doorbell local repeater?
Good morning Tim,
I have a device that is essentially a microphone placed near your doorbell chime 9powered by 4 AA batteries (or maybe AAA) that then transmits to an AC powered ringer that you plug into a convenient outlet. Here is one from Home Depot: https://www.homedepot.com/p/Heath-Ze...8-02/100627086 Now this unit is 120V, and I have no idea if you have Home Depot stores in your 240VAC country, but there must be something similar. The pickup units batteries seem to last 2-3 years, and it rarely false triggers, unless I slam the closet door it is mounted near. Best regards, another Tim On 10/22/2020 6:37 AM, T i m wrote: Hi all, I appreciate this is a design rather than repair question but I appreciate there are some very skilled people here. ;-) Scenario. I have a wired bellpush on the front door (frame) that runs to a battery 'Ding-dong' type solenoid chime further back in the house, the idea being that 'we' can hear it anywhere in the house (we can) and also in the back garden if we are lucky (we also sometimes can). The 'problem' is that you can't generally hear it outside the DG front door and so couriers often ring the bell *and* repeatedly bang on the glass door or flap the letterbox flap, sometimes winding the dog up thinking it's an aggressor. ;-) So, I was just wondering ... if I had some sort of small electro-mechanical buzzer (possibly to also give physical feedback), just inside the front door (on the inside door frame, directly behind the bell push for best feedback and easy wiring) that you could hear from the outside, that might give anyone on the outside some level of positive feedback that the bell had worked (hopefully anyway)? So, I am limited to 6V DC via the 4 x C cells (currently Ni-Mh's so only 4.8V) and don't want to add any real parasitic drain, especially if I go back to alkaline cells to get the full 6V. So I was thinking (but am no electronics design engineer) of some form of diode fed - series resistance cap that could be charged by the 6V supply seen at the back of the bell push that could then be discharged via a low voltage buzzer when the button is pressed (even if only once and for ~1s) ... and would then reset ready for another press say in 30 seconds time (given the original doorbell will continue to work as normal etc). Things I believe are relevant ... you would need a cap big enough to provide as good a quality level of power long enough to give a significant 'buzz' to be heard. The charging resistance would need to be low enough to not cause the bell to hang on the 'Ding', once the button was released (the chime solenoid just returns under spring power when no current flows but might be 'held' by a much lower current (so no proper 'dong'). I didn't know if the buzzer trigger could / should be done by a self latching circuit of some sort or if one should use a zener to manage the voltage allowing a better release action? I am aware of all the other options like using a mains transformer or wireless repeater / converters, I was really only interested in seeing if such a direct repeater could be practical? ;-) Cheers, T i m p.s. Yesterday I successfully repaired one of those plug in wirelessly charged PIR / power cut type torch / lights. It was a resistor that burns out in the 240V base and is replaced (sometimes along with a transistor and cap) and normally get's them working again. Unfortunately the Lithium (14430) battery in the torch part had gone very flat (sub 1V) so I have a replacement on the way. |
#3
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Battery doorbell local repeater?
What about installing another light-draw chime just inside your door? Activating the button would trip both. Just put it in series with the bell.
KISS Peter Wieck Melrose Park, PA |
#4
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Battery doorbell local repeater?
On Thu, 22 Oct 2020 08:26:49 -0400, Tim Schwartz
wrote: Good morning Tim, Hi Tim! I have a device that is essentially a microphone placed near your doorbell chime 9powered by 4 AA batteries (or maybe AAA) that then transmits to an AC powered ringer that you plug into a convenient outlet. The problem is, I don't have a 'convenient outlets' near the front door. ;-( Here is one from Home Depot: https://www.homedepot.com/p/Heath-Ze...8-02/100627086 Now this unit is 120V, and I have no idea if you have Home Depot stores in your 240VAC country, but there must be something similar. Yeah, there are a few similar things available over here and even a doorbell that allows you to hook up a conventional wired / battery bell and trigger a wireless one, again, I didn't really want to have anything 'else' if I could get away with a small buzzer / sounder inside the front door. That would help the Mrs hear it as she's normally just the other side of the internal wall in the lounge. ;-) The pickup units batteries seem to last 2-3 years, and it rarely false triggers, unless I slam the closet door it is mounted near. Hehe. We had the similar thing again this morning ... I heard the doorbell go but as I was getting up to answer the door, he was knocking on the glass because *he* hadn't seen / heard any feedback that the bell was working. If I can find a suitable mini-buzzer it may well work in series with the existing bell and so would be very easy to tack into the existing circuit and mount just behind the bell push. We hear both things, they hear the buzzer. ;-) Cheers, T i m |
#5
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Battery doorbell local repeater?
Two thoughts, from a mechanical engineer.
1. Cheap solution: write DOORBELL WORKS! on a 3x5 card and tape it to the door. 2. Also cheap solution: if you're like 90% of people you have a smoke alarm that doesn't work because you've changed the battery. Take out the little piezo speaker and put it on the other side of the door. Wire it to the buzzer. Include the 9 volt battery as needed. (not sure exactly how your doorbell is powered. I apologize in advance for violating the Terms of Use of this forum, which include to provide the most complicated DIY electronic design project possible for any problem that might have a simpler solution. |
#6
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Battery doorbell local repeater?
On Thu, 22 Oct 2020 06:28:39 -0700 (PDT), "
wrote: What about installing another light-draw chime just inside your door? Activating the button would trip both. Just put it in series with the bell. That was another thought Peter (and was suggested elsewhere), maybe a electromechanical buzzer so they hear the buzzer directly and also any reverberations that travel though the frame etc. KISS Quite, but the issue with the above is that I'd need to get lucky and find something that would work itself and allow the existing bell to ring, especially when it's already running on a reduced voltage (4.8V of Ni-Mh rather than 6V of alkaline). That's why I was trying to isolate the existing bell functionality and leech some power off that to run an auxiliary sounder. Cheers, T i m |
#7
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Battery doorbell local repeater?
On Thu, 22 Oct 2020 08:32:25 -0700 (PDT), Tim R
wrote: Two thoughts, from a mechanical engineer. 1. Cheap solution: write DOORBELL WORKS! on a 3x5 card and tape it to the door. Worth a try ... except the batteries do go flat and so the bell doesn't work .. ;-( I was going to include an LED in the bell push that lights or flashes when they press the button (discharging cap) but again, that's assuming they look for such (and most deliveries are in the day and this would be South facing). 2. Also cheap solution: if you're like 90% of people you have a smoke alarm that doesn't work because you've changed the battery. Take out the little piezo speaker and put it on the other side of the door. That was the sort of idea of my plan. ;-) Wire it to the buzzer. Include the 9 volt battery as needed. (not sure exactly how your doorbell is powered. 6V in series with the solenoid and bell push. I apologize in advance for violating the Terms of Use of this forum, which include to provide the most complicated DIY electronic design project possible for any problem that might have a simpler solution. ;-) The thing is, I'm not sure a simple solution works in this situation. What I was hoping for is a 'subtle' (electronically) solution that does what I need. So, under normal circumstances there will be 6V DC across the open bell push. I have a cct in parallel with that that charges a cap via a diode and resistor I have a small 'remote' PSU that wouldn't be affected by the bell push shorting it out (because of the diode). If something could latch and discharge the cap though a buzzer and release once it has, everything else the doorbell will 1) work as designed and 2) the 'repeater' should work without much interference to the existing solution, albeit other than a slightly increased load on the battery. If I could find a buzzer that works from 1.2V, I could put a couple of fwd biased diodes across it and went back to alkaline cells, that should work and be as simple as it can get? Cheers T i m |
#8
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Battery doorbell local repeater?
Keeping in mind that this forum exists so that the uninformed may provide the least appropriate, most complicated, least reliable solutions for established problems with established (and reliable) solutions such that the requester of such information may be relieved of taking responsibility to do the right thing in the first place, over-complication is the natural order of things (Thank you, TImothy).
https://www.radioshack.com/products/...nt=20332219525 Put it in a small WireMold box right inside the door by the door jamb. Feed it from the bell wire - take one lead, and connect the buzzer in SERIES with that lead. At 58 ma, it will not overload your transformer. Peter Wieck Melrose Park, PA |
#9
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Battery doorbell local repeater?
On Thu, 22 Oct 2020 11:32:13 -0700 (PDT), "
wrote: Keeping in mind that this forum exists so that the uninformed may provide the least appropriate, most complicated, least reliable solutions for established problems with established (and reliable) solutions such that the requester of such information may be relieved of taking responsibility to do the right thing in the first place, over-complication is the natural order of things (Thank you, TImothy). I'm keeping out of that one. ;-) https://www.radioshack.com/products/...nt=20332219525 Put it in a small WireMold box Or I could design / 3D print something. If it were white it could stay as it is. right inside the door by the door jamb. Yeah, as long as it will fit on the inner frame (inwards opening door) that will be fine. The frame is the same size as the end of the corridor (the door was made to fit the space) so there isn't a lot of clearance on either side for much. Feed it from the bell wire - take one lead, and connect the buzzer in SERIES with that lead. OK. At 58 ma, it will not overload your transformer. Well, it's batteries but if the buzzer requires a minimum of 6V and the battery is only 6V, I'm not sure either buzzer or bell will still work will they? This was why I was thinking of some way of 'phatoming the 6V (battery) psu to the bellpush and using that to source the voltage often required to run these sounders? I wasn't looking to make it complicated on purpose, I just couldn't see how it could be KISS and still do what I want / need? Something that could be easily modified is the PSU for the bell itself. The bell sits on the side of the stairs so a small hole though the back of the bell box for a cable to a small 12V battery (sealed Lead acid or possibly a similar voltage diy Li-Ion pack) should be doable. *Then* I have the spare 6V for a frame mounted buzzer. ;-) Cheers, T i m |
#10
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Battery doorbell local repeater?
On 10/22/2020 12:40 PM, T i m wrote:
.... If I could find a buzzer that works from 1.2V, ... 1.5v: https://www.futureelectronics.com/c/...products&text= |
#11
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Battery doorbell local repeater?
On Thu, 22 Oct 2020 19:37:47 -0400, Bob Engelhardt
wrote: On 10/22/2020 12:40 PM, T i m wrote: ... If I could find a buzzer that works from 1.2V, ... 1.5v: https://www.futureelectronics.com/c/...products&text= Thanks for that Bob. I'm, confused. I asked about one of those (Electro-Acoustic Transducer) on eBay, if it was a speaker or if it produced a noise on it's own, just with a supply voltage etc and they replied it was just a speaker, requiring external driving (assuming I'm seeing what you intended on the link)? Cheers, T i m |
#12
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Battery doorbell local repeater?
On 10/23/2020 2:15 PM, T i m wrote:
On Thu, 22 Oct 2020 19:37:47 -0400, Bob Engelhardt wrote: On 10/22/2020 12:40 PM, T i m wrote: ... If I could find a buzzer that works from 1.2V, ... 1.5v: https://www.futureelectronics.com/c/...products&text= Thanks for that Bob. I'm, confused. I asked about one of those (Electro-Acoustic Transducer) on eBay, if it was a speaker or if it produced a noise on it's own, just with a supply voltage etc and they replied it was just a speaker, requiring external driving (assuming I'm seeing what you intended on the link)? Cheers, T i m You're right, sorry. Brain fart. These are true buzzers, a couple work down to 1.2v: https://tinyurl.com/yyv9oq85 |
#13
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Battery doorbell local repeater?
On Friday, October 23, 2020 at 2:15:46 PM UTC-4, T i m wrote:
I'm, confused. I asked about one of those (Electro-Acoustic Transducer) on eBay, if it was a speaker or if it produced a noise on it's own, just with a supply voltage etc and they replied it was just a speaker, requiring external driving (assuming I'm seeing what you intended on the link)? Is the doorbell mechanical, with a coil and contacts that open and close? If so, a speaker in series would make noise from the interruptions in current flow. It might be loud enough for your needs. The only way to find out is to test it with any old speaker that you have laying around. |
#14
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Battery doorbell local repeater?
You could put the at-the-door buzzer in parallel with the interior bell.
It would require a separate battery & its occasional replacement. ------||---+---||----- | | | 1.2v | Interior Buzzer push Bell | button | AA batt | 6v batt | | | |-----------+-----------| |
#15
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Battery doorbell local repeater?
On 22/10/2020 21:37, T i m wrote:
Hi all, I appreciate this is a design rather than repair question but I appreciate there are some very skilled people here. ;-) Scenario. I have a wired bellpush on the front door (frame) that runs to a battery 'Ding-dong' type solenoid chime further back in the house, the idea being that 'we' can hear it anywhere in the house (we can) and also in the back garden if we are lucky (we also sometimes can). The 'problem' is that you can't generally hear it outside the DG front door and so couriers often ring the bell *and* repeatedly bang on the glass door or flap the letterbox flap, sometimes winding the dog up thinking it's an aggressor. ;-) So, I was just wondering ... if I had some sort of small electro-mechanical buzzer (possibly to also give physical feedback), just inside the front door (on the inside door frame, directly behind the bell push for best feedback and easy wiring) that you could hear from the outside, that might give anyone on the outside some level of positive feedback that the bell had worked (hopefully anyway)? So, I am limited to 6V DC via the 4 x C cells (currently Ni-Mh's so only 4.8V) and don't want to add any real parasitic drain, especially if I go back to alkaline cells to get the full 6V. So I was thinking (but am no electronics design engineer) of some form of diode fed - series resistance cap that could be charged by the 6V supply seen at the back of the bell push that could then be discharged via a low voltage buzzer when the button is pressed (even if only once and for ~1s) ... and would then reset ready for another press say in 30 seconds time (given the original doorbell will continue to work as normal etc). Things I believe are relevant ... you would need a cap big enough to provide as good a quality level of power long enough to give a significant 'buzz' to be heard. The charging resistance would need to be low enough to not cause the bell to hang on the 'Ding', once the button was released (the chime solenoid just returns under spring power when no current flows but might be 'held' by a much lower current (so no proper 'dong'). I didn't know if the buzzer trigger could / should be done by a self latching circuit of some sort or if one should use a zener to manage the voltage allowing a better release action? Do you even need any trigger/latching circuit? Often doorbells only make a sound when the button is pressed, so the visitor should not be bothered by that, and it would not require such a trigger circuit. Why not do pretty much exactly what you already suggested: Get a big capacitor (perhaps a couple of 1 Farad 5.5V supercapacitors in series, they are quite small and should withstand 6V even without equalising resistors), charge the capacitor from the existing doorbell wiring via a 1N4004...1N4007 diode, and put a piezo or mechanical buzzer connected in parallel with the diode in the direction with the positive of the buzzer connected to the cathode of the diode. During charging, the buzzer will experience 0.7V of reverse bias which probably won't bother it, and when the button is pressed, the diode is reverse biased and the buzzer receives whatever voltage the capacitor was charged to. For simplicity, don't bother with any extra series resistor to limit the charging current, as that would expose the buzzer to more reverse bias, and it is probably unnecessary after the first charging cycle. The capacitor won't have time to discharge much when the button is pressed, which means it won't take long to recharge either. When the circuit is initially installed, it might take a while to charge the capacitor, perhaps a minute or so. So you need capacitor, diode, buzzer. If the existing bell has a lot of inductance, when the button is released there might be a large voltage kick across the switch. The diode ought to catch this so I would not expect it to fry the new piezo buzzer, but it might alter the sound of the existing doorbell when it releases. |
#16
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Battery doorbell local repeater?
On Monday, October 26, 2020 at 8:03:22 AM UTC-4, Chris Jones wrote:
On 22/10/2020 21:37, T i m wrote: Hi all, I appreciate this is a design rather than repair question but I appreciate there are some very skilled people here. ;-) Scenario. I have a wired bellpush on the front door (frame) that runs to a battery 'Ding-dong' type solenoid chime further back in the house, the idea being that 'we' can hear it anywhere in the house (we can) and also in the back garden if we are lucky (we also sometimes can). The 'problem' is that you can't generally hear it outside the DG front door and so couriers often ring the bell *and* repeatedly bang on the glass door or flap the letterbox flap, sometimes winding the dog up thinking it's an aggressor. ;-) So, I was just wondering ... if I had some sort of small electro-mechanical buzzer (possibly to also give physical feedback), just inside the front door (on the inside door frame, directly behind the bell push for best feedback and easy wiring) that you could hear from the outside, that might give anyone on the outside some level of positive feedback that the bell had worked (hopefully anyway)? So, I am limited to 6V DC via the 4 x C cells (currently Ni-Mh's so only 4.8V) and don't want to add any real parasitic drain, especially if I go back to alkaline cells to get the full 6V. So I was thinking (but am no electronics design engineer) of some form of diode fed - series resistance cap that could be charged by the 6V supply seen at the back of the bell push that could then be discharged via a low voltage buzzer when the button is pressed (even if only once and for ~1s) ... and would then reset ready for another press say in 30 seconds time (given the original doorbell will continue to work as normal etc). Things I believe are relevant ... you would need a cap big enough to provide as good a quality level of power long enough to give a significant 'buzz' to be heard. The charging resistance would need to be low enough to not cause the bell to hang on the 'Ding', once the button was released (the chime solenoid just returns under spring power when no current flows but might be 'held' by a much lower current (so no proper 'dong'). I didn't know if the buzzer trigger could / should be done by a self latching circuit of some sort or if one should use a zener to manage the voltage allowing a better release action? Do you even need any trigger/latching circuit? Often doorbells only make a sound when the button is pressed, so the visitor should not be bothered by that, and it would not require such a trigger circuit. Why not do pretty much exactly what you already suggested: Get a big capacitor (perhaps a couple of 1 Farad 5.5V supercapacitors in series, they are quite small and should withstand 6V even without equalising resistors), charge the capacitor from the existing doorbell wiring via a 1N4004...1N4007 diode, and put a piezo or mechanical buzzer connected in parallel with the diode in the direction with the positive of the buzzer connected to the cathode of the diode. During charging, the buzzer will experience 0.7V of reverse bias which probably won't bother it, and when the button is pressed, the diode is reverse biased and the buzzer receives whatever voltage the capacitor was charged to. For simplicity, don't bother with any extra series resistor to limit the charging current, as that would expose the buzzer to more reverse bias, and it is probably unnecessary after the first charging cycle. The capacitor won't have time to discharge much when the button is pressed, which means it won't take long to recharge either. When the circuit is initially installed, it might take a while to charge the capacitor, perhaps a minute or so. So you need capacitor, diode, buzzer. If the existing bell has a lot of inductance, when the button is released there might be a large voltage kick across the switch. The diode ought to catch this so I would not expect it to fry the new piezo buzzer, but it might alter the sound of the existing doorbell when it releases. Hey, I like it, but we can complicate it more. I think we need a Raspberry Pi or an Arduino in the circuit controlling it. |
#17
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Battery doorbell local repeater?
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#18
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Battery doorbell local repeater?
On Monday, October 26, 2020 at 1:38:41 PM UTC-4, Ralph Mowery wrote:
In article , says... Hey, I like it, but we can complicate it more. I think we need a Raspberry Pi or an Arduino in the circuit controlling it. Outside of the programming the Arduino is very simple to use for many things. They can be bought for less than $ 5 from many places in China. That is often less expensive than many of the relays it would take to do the job. I need to learn more about that; this is one of those technical advances that kind of sneaked by me. I was trying to figure out if I could replace my washer timer with something like that, 30 year old Maytag and can't get parts, but then it started working again. They really really don't make them like that anymore. |
#20
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Battery doorbell local repeater?
30 year old Maytag and can't get parts, but then it started working again.
https://www.partselect.com/Maytag-Washer-Timers.htm https://www.partsimple.com/may-wp220...gaAjY9EALw_wcB https://www.youtube.com/watch?v=IRtHni3LuXQ I doubt if there is a part or piece in any Maytag of similar vintage that cannot be found somewhere, and in short order. We have a Maytag dryer at our summer house, and just replaced the belt, rollers, idler and motor with new parts (made in Mexico and the USA) all for less than $100 installed (by me). It was made in 1971. They really really don't make them like that anymore. And for very good reason: 30 - 45 gallons of water per load. Up to 2 gallons of water left behind (full load) that has to be dried. And more. But, they do work well, when they work. Peter Wieck Melrose Park, PA |
#21
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Battery doorbell local repeater?
On Tuesday, October 27, 2020 at 10:29:39 AM UTC-4, Peter W. wrote:
30 year old Maytag and can't get parts, but then it started working again.. https://www.partselect.com/Maytag-Washer-Timers.htm https://www.partsimple.com/may-wp220...gaAjY9EALw_wcB https://www.youtube.com/watch?v=IRtHni3LuXQ I doubt if there is a part or piece in any Maytag of similar vintage that cannot be found somewhere, and in short order. We have a Maytag dryer at our summer house, and just replaced the belt, rollers, idler and motor with new parts (made in Mexico and the USA) all for less than $100 installed (by me). It was made in 1971. They really really don't make them like that anymore. And for very good reason: 30 - 45 gallons of water per load. Up to 2 gallons of water left behind (full load) that has to be dried. And more. But, they do work well, when they work. Peter Wieck Melrose Park, PA I did go to those websites and find my part number, only to see them all marked "out of stock." But then the problem solved itself, so I'm fine. If I get another 20 years out of it, that's probably more than I have left anyway! Hee, hee. But appliances controlled with expensive electronic boards, like modern refrigerators, washers and dryers, scare me. Power fluctuations take them out so easily. I hate extended warranties but these may be necessary for some equipment. That mechanical timer could be replaced, with some effort for one that didn't quite fit maybe. Or I could put 8 toggle switches in a box and do it manually if I had to. Once a board goes I'm stuck. |
#22
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Battery doorbell local repeater?
On Mon, 26 Oct 2020 10:45:04 -0700 (PDT), Tim R
wrote: On Monday, October 26, 2020 at 1:38:41 PM UTC-4, Ralph Mowery wrote: In article , says... Hey, I like it, but we can complicate it more. I think we need a Raspberry Pi or an Arduino in the circuit controlling it. Outside of the programming the Arduino is very simple to use for many things. They can be bought for less than $ 5 from many places in China. That is often less expensive than many of the relays it would take to do the job. I need to learn more about that; this is one of those technical advances that kind of sneaked by me. I was trying to figure out if I could replace my washer timer with something like that, 30 year old Maytag and can't get parts, but then it started working again. snip I setup an Arduino (Uno) as the heart of a semi-automated controller for my BIL's extensive model railway layout. The test track I have here is just a 3m straight length of (OO) track on a bit of timber with a small passing place in the middle section, joined to the main line with a couple of sets of points. There are diodes in one track leg near the ends to kill the power to the loco if it was to overrun (but allowing it to reverse out). There are 4 coded IR sensors on the track, two near the ends, two just outside the points. Arduino ramps up the PWM, loco pulls away and accelerates (with inertia) to full speed till it passes the sensor past the distant points then decelerates (again with inertia) and then creeps to the furthest sensor then stops. The points change (capacitor discharge via electronic bridge drivers) then the loco pulls away, round the bypass and to the other end. Rinse / repeat. The idea was to have some automated bits of track that ran stuff at the back of his main layout, just to keep something running while he was working on the layout or running other stuff himself. The full project was going to be a main line with two sidings at each end. The track would be broken up into at least 5 sections, the main run and the 4 sidings. All 5 could be driven independently (but as one) and each section 'sensed' for current draw to determine occupancy / transition. 3 locos (probably railcars / trams) could be placed on the track, two in any of the 4 'ends' and one on the main line. On startup, the Arduino would test each section of track for occupancy (test current pulse), set the points to one of the empty sidings and drive any loco on the main line into an empty siding. Now it would randomly select one of the two trains facing the empty siding at the remote end and set the live line to that siding. It would then slowly run out onto the main line (past a sensor), accelerate to full speed (user setable with a pot) to the remote sensor then slowing though the points and to the end on the empty siding. We could add a halt / station in the middle if we wanted. Re evaluate and run again, either randomly or cycling though all three locos / units.. ;-) During out initial trials we learned we would probably have to select a small subset of similar spec models from his extensive collection to ensure the performance of each loco was similar. Because he has quite a collection, he really didn't want to go digital, hence all the intelligence had to be in the track. We might also need to use the Arduino to drive an independent PWM controller with feedback, to allow better control. I have an Arduino Mega running the 3D printer I built a few years back. ;-) I have a Raspberry Pi3B running Open Media Vault (NAS) on a 3TB USB drive and another running TVHeadend with a couple of HD TV tuners. All good fun. ;-) Cheers, T i m |
#23
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Battery doorbell local repeater?
On Mon, 26 Oct 2020 23:03:09 +1100, Chris Jones
wrote: snip I didn't know if the buzzer trigger could / should be done by a self latching circuit of some sort or if one should use a zener to manage the voltage allowing a better release action? Do you even need any trigger/latching circuit? Possibly not, with the right solution. ;-) Often doorbells only make a sound when the button is pressed, This one is just a solenoid hitting one chime (Ding) and then dropping back to the other (dong) when the button is released. so the visitor should not be bothered by that, and it would not require such a trigger circuit. Ok ... Why not do pretty much exactly what you already suggested: Get a big capacitor (perhaps a couple of 1 Farad 5.5V supercapacitors in series, they are quite small and should withstand 6V even without equalising resistors), charge the capacitor from the existing doorbell wiring via a 1N4004...1N4007 diode, Ok, so when I first hooked it up it will pull the bell in 'Ding' and hold it in till the charging current dropped back enough to allow the solenoid to release (which might be slow so we might not ever hear a clear 'dong')? and put a piezo or mechanical buzzer connected in parallel with the diode in the direction with the positive of the buzzer connected to the cathode of the diode. During charging, the buzzer will experience 0.7V of reverse bias which probably won't bother it, and when the button is pressed, the diode is reverse biased and the buzzer receives whatever voltage the capacitor was charged to. Ok. I follow that. For simplicity, don't bother with any extra series resistor to limit the charging current, as that would expose the buzzer to more reverse bias, What if the buzzer was (across your diode) in series ... with another reversed diode and resistor in parallel? eg, charging current passes though original diode / buzzer, combo, through the resistor and into the cap. Then when the button is pressed the cap charge passes through the second diode, though the buzzer and to the switch (and back to the -Ve of the cap etc)? and it is probably unnecessary after the first charging cycle. The capacitor won't have time to discharge much when the button is pressed, which means it won't take long to recharge either. What sort of leakage do these caps have Chris? When the circuit is initially installed, it might take a while to charge the capacitor, perhaps a minute or so. Understood, or I could pre-charge it? ;-) So you need capacitor, diode, buzzer. plus another diode and suitable resistor ... If the existing bell has a lot of inductance, when the button is released there might be a large voltage kick across the switch. Well it is a solenoid so it might have a bit. The diode ought to catch this so I would not expect it to fry the new piezo buzzer, I was hoping to go for a electro mechanical buzzer so that it actually resonated the door frame a bit, rather than just be a beep in parallel with the existing doorbell. but it might alter the sound of the existing doorbell when it releases. Not if I get the charging resistor right? Basically, I don't think I need a big cap, just one big enough to allow the buzzer to sound briefly, just to provide feedback to anyone outside that the button did work (and ideally I wouldn't want it to run much longer in case they did hold their finger on the button). I'll have to rig something up and see how it goes (and it's easier to find 6V buzzers). ;-) Cheers, T i m |
#24
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Battery doorbell local repeater?
https://www.amazon.com/American-Scie.../dp/B003VP0DQ2
Not so hard. Eschew needless complexity - William of Occam Peter Wieck Melrose Park, PA |
#25
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Battery doorbell local repeater?
On Wed, 28 Oct 2020 04:41:06 -0700 (PDT), "Peter W."
wrote: https://www.amazon.com/American-Scie.../dp/B003VP0DQ2 Not so hard. Cool, I've ordered the same thing (and in white) from Amazon UK. ;-) Eschew needless complexity - William of Occam Agreed, if at all possible and as long as it works. ;-) Do you think I'll need to limit the voltage across the buzzer (2 (/3) diodes in series in parallel with the buzzer?) and that the existing bell draws at least 25mA? "* Minimum Input Voltage: 1.3V* Maximum Input Voltage: 2V* Current Consumption: 25mA* Nominal Output @ 30cm: 75dB* Output Frequency: 400Hz* " Cheers, T i m |
#26
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Battery doorbell local repeater?
On 28/10/2020 10:45, T i m wrote:
On Mon, 26 Oct 2020 23:03:09 +1100, Chris Jones wrote: snip I didn't know if the buzzer trigger could / should be done by a self latching circuit of some sort or if one should use a zener to manage the voltage allowing a better release action? Do you even need any trigger/latching circuit? Possibly not, with the right solution. ;-) Often doorbells only make a sound when the button is pressed, This one is just a solenoid hitting one chime (Ding) and then dropping back to the other (dong) when the button is released. so the visitor should not be bothered by that, and it would not require such a trigger circuit. Ok ... Why not do pretty much exactly what you already suggested: Get a big capacitor (perhaps a couple of 1 Farad 5.5V supercapacitors in series, they are quite small and should withstand 6V even without equalising resistors), charge the capacitor from the existing doorbell wiring via a 1N4004...1N4007 diode, Ok, so when I first hooked it up it will pull the bell in 'Ding' and hold it in till the charging current dropped back enough to allow the solenoid to release (which might be slow so we might not ever hear a clear 'dong')? and put a piezo or mechanical buzzer connected in parallel with the diode in the direction with the positive of the buzzer connected to the cathode of the diode. During charging, the buzzer will experience 0.7V of reverse bias which probably won't bother it, and when the button is pressed, the diode is reverse biased and the buzzer receives whatever voltage the capacitor was charged to. Ok. I follow that. For simplicity, don't bother with any extra series resistor to limit the charging current, as that would expose the buzzer to more reverse bias, What if the buzzer was (across your diode) in series ... with another reversed diode and resistor in parallel? eg, charging current passes though original diode / buzzer, combo, through the resistor and into the cap. Then when the button is pressed the cap charge passes through the second diode, though the buzzer and to the switch (and back to the -Ve of the cap etc)? I had considered suggesting such an arrangement, but then I thought that the simpler option would probably be good enough. and it is probably unnecessary after the first charging cycle. The capacitor won't have time to discharge much when the button is pressed, which means it won't take long to recharge either. What sort of leakage do these caps have Chris? Here is a datasheet. Tens of microamperes or less. I didn't know but they come in voltage ratings above 5.5V so you would only need one capacitor: https://au.mouser.com/datasheet/2/40...CM-1018838.pdf When the circuit is initially installed, it might take a while to charge the capacitor, perhaps a minute or so. Understood, or I could pre-charge it? ;-) So you need capacitor, diode, buzzer. plus another diode and suitable resistor ... If the existing bell has a lot of inductance, when the button is released there might be a large voltage kick across the switch. Well it is a solenoid so it might have a bit. The diode ought to catch this so I would not expect it to fry the new piezo buzzer, I was hoping to go for a electro mechanical buzzer so that it actually resonated the door frame a bit, rather than just be a beep in parallel with the existing doorbell. but it might alter the sound of the existing doorbell when it releases. Not if I get the charging resistor right? True. That's the main advantage I can think of for putting a charging resistor. There might be an argument for using a zener diode rather than a rectifier diode in parallel with the charging resistor, as I don't know whether breakdown might be destructive for a diode not intended as a zener. Basically, I don't think I need a big cap, just one big enough to allow the buzzer to sound briefly, just to provide feedback to anyone outside that the button did work (and ideally I wouldn't want it to run much longer in case they did hold their finger on the button). Yes, a smaller capacitor would do if you have a suitable one on hand. I'll have to rig something up and see how it goes (and it's easier to find 6V buzzers). ;-) I think you should try it and please report back how it goes. |
#27
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Battery doorbell local repeater?
Do you think I'll need to limit the voltage across the buzzer (2 (/3) diodes in series in parallel with the buzzer?) and that the existing bell draws at least 25mA? That would depend very much on how long your delivery individual holds down the button. But a couple-of-ohms, 1-watt resistor, or so, in parallel to the buzzer should give all the protection you need. One watt is crazy-overkill, but cheap enough. Peter Wieck Melrose Park, PA |
#28
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Battery doorbell local repeater?
On Thu, 29 Oct 2020 03:43:19 -0700 (PDT), "
wrote: Do you think I'll need to limit the voltage across the buzzer (2 (/3) diodes in series in parallel with the buzzer?) and that the existing bell draws at least 25mA? That would depend very much on how long your delivery individual holds down the button. If it's anything like the Hermes delivery at 8 last night, too long (or two many times). ;-( But a couple-of-ohms, 1-watt resistor, or so, in parallel to the buzzer should give all the protection you need. So if using a resistor in that role I really need to match the resistance to the resistance of the solenoid to give me the right voltage drop over the buzzer (potential divider), hoping the worst case is not too much voltage across the buzzer and when the batteries are on the way out, enough for the buzzer bit to still work? If I had a suitably low value (ww?) pot, I could put that across the buzzer then tune it for the best sound with the Ni-Mh cells (then replace it with a fixed resistor etc)? One watt is crazy-overkill, but cheap enough. Why wouldn't a 'voltage' regulated solution be better, given how little voltage we have spare to play with and the fact that the voltage will change with time? It looks like you can get 1.5V zeners so as long as they can manage the current though the existing bell and the back EMF etc, wouldn't that be the more subtle way of managing it all? idea I just stuck my DMM across the contacts on the bell push (at the bell itself) and with a 6V battery supply I measure ~750mA (dropping to ~730 after a few seconds). That puts the bell solenoid resistance at around 8 ohms (plus what I would get via the cabling etc). If the buzzer draws 25mA at 1.5V then the buzzers resistance is around 60 ohms (I know that isn't ever going to be a pure resistor, unlike the saturated solenoid) so adding that in series with the bell is going to give me around 70 ohms and a maximum current of ~85mA. That's roughly 5V across the buzzer and 1V across the bell. Putting a 2 ohm resistor in parallel with the buzzer will give me just over 10 ohms in total, so back up to around 600+mA, and so 1.2V across the buzzer and 4.8V across the bell (and I know it works with 4.8V's worth of rechargeables. ;-) However, aren't we wasting energy in a resistor system, rather than clamping voltage using a (say) a zener or is it the same thing? Cheers, T i m |
#29
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Battery doorbell local repeater?
On Thu, 29 Oct 2020 13:57:16 +1100, Chris Jones
wrote: snip and it is probably unnecessary after the first charging cycle. The capacitor won't have time to discharge much when the button is pressed, which means it won't take long to recharge either. What sort of leakage do these caps have Chris? Here is a datasheet. Tens of microamperes or less. I didn't know but they come in voltage ratings above 5.5V so you would only need one capacitor: https://au.mouser.com/datasheet/2/40...CM-1018838.pdf Interesting, thanks. Are these the sorts of things they have in these clever capacitive based vehicle jump starting units? snip but it might alter the sound of the existing doorbell when it releases. Not if I get the charging resistor right? True. That's the main advantage I can think of for putting a charging resistor. There might be an argument for using a zener diode rather than a rectifier diode in parallel with the charging resistor, as I don't know whether breakdown might be destructive for a diode not intended as a zener. Understood. snip I'll have to rig something up and see how it goes (and it's easier to find 6V buzzers). ;-) I think you should try it and please report back how it goes. You should see from elsewhere I'm going to try the low voltage series buzzer first and yes, of course I'll report back as I can't be the only one in this position who might appreciate a 'simple' solution? ;-) Cheers, T i m |
#30
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Battery doorbell local repeater?
Y'all are way over thinking this.
Just replace the door bell button with a DPST NO push button. Then use the other half to do what ever you want. -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
#31
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Battery doorbell local repeater?
However, aren't we wasting energy in a resistor system, rather than clamping voltage using a (say) a zener or is it the same thing? The resistor is on play only when the button is being pushed. So the amount of energy 'wasted' is negligible. The buzzer is rated up to two (2) volts. Which suggests that a 1.5 ohm resistor will accommodate voltage swings from the battery and still protect the buzzer. Resistors are far less complicated (and thereby more reliable) than a diode, more so if that diode is a zener. The idea is to pass enough current to trip the bell solenoid, yet not damage the buzzer. I am not so sure batteries, buttons, buzzers and bells understand the concept of "subtle" on the one hand. They may understand "elegant" on the other hand. On the gripping hand, they certainly understand "simple". I am trying to limit the number of parts involved with the least complicated, most efficient solution that uses what is already in place, and also does not involve brain-damage. Enjoy! Peter Wieck Melrose Park, PA |
#32
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Battery doorbell local repeater?
On Thursday, October 29, 2020 at 8:26:21 AM UTC-5, Fox's Mercantile wrote:
Y'all are way over thinking this. Just replace the door bell button with a DPST NO push button. Then use the other half to do what ever you want. -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com Look at you and pony pete working in tandem. You too have come a long way. Keep up the good work. |
#33
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Battery doorbell local repeater?
On Thursday, October 29, 2020 at 9:09:46 AM UTC-5, Peter W. wrote:
However, aren't we wasting energy in a resistor system, rather than clamping voltage using a (say) a zener or is it the same thing? The resistor is on play only when the button is being pushed. So the amount of energy 'wasted' is negligible. The buzzer is rated up to two (2) volts. Which suggests that a 1.5 ohm resistor will accommodate voltage swings from the battery and still protect the buzzer. Resistors are far less complicated (and thereby more reliable) than a diode, more so if that diode is a zener. The idea is to pass enough current to trip the bell solenoid, yet not damage the buzzer. I am not so sure batteries, buttons, buzzers and bells understand the concept of "subtle" on the one hand. They may understand "elegant" on the other hand. On the gripping hand, they certainly understand "simple". I am trying to limit the number of parts involved with the least complicated, most efficient solution that uses what is already in place, and also does not involve brain-damage. Enjoy! Peter Wieck Melrose Park, PA There you go Petey! See, it's not so hard to be helpful. Just don't inject to much of your inner thoughts when you reply. Give only pertinent information like in this example. |
#34
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Battery doorbell local repeater?
Boo
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#35
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Battery doorbell local repeater?
On 10/29/20 12:00 PM, Edward Hernandez wrote:
Look at you and pony pete working in tandem. You fix that piece of **** charger yet asshole? -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
#36
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Battery doorbell local repeater?
On Thursday, October 29, 2020 at 12:46:42 PM UTC-5, Fox's Mercantile wrote:
On 10/29/20 12:00 PM, Edward Hernandez wrote: Look at you and pony pete working in tandem. You fix that piece of **** charger yet asshole? -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com Hey Gramps. What you mean to say is, "How else can I serve those in this forum community." |
#37
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Battery doorbell local repeater?
On Tuesday, October 27, 2020 at 11:12:19 AM UTC-4, wrote:
I did go to those websites and find my part number, only to see them all marked "out of stock." But then the problem solved itself, so I'm fine. If I get another 20 years out of it, that's probably more than I have left anyway! Hee, hee. But appliances controlled with expensive electronic boards, like modern refrigerators, washers and dryers, scare me. Power fluctuations take them out so easily. I hate extended warranties but these may be necessary for some equipment. That mechanical timer could be replaced, with some effort for one that didn't quite fit maybe. Or I could put 8 toggle switches in a box and do it manually if I had to. Once a board goes I'm stuck. Have you tried https://www.searspartsdirect.com/ |
#38
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Battery doorbell local repeater?
On 10/29/20 2:16 PM, Edward Hernandez wrote:
On Thursday, October 29, 2020 at 12:46:42 PM UTC-5, Fox's Mercantile wrote: On 10/29/20 12:00 PM, Edward Hernandez wrote: Look at you and pony pete working in tandem. You fix that piece of **** charger yet asshole? -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com Hey Gramps. What you mean to say is, "How else can I serve those in this forum community." In other words no. I figured as much. -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
#39
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Battery doorbell local repeater?
On Friday, October 30, 2020 at 12:02:58 AM UTC-5, Fox's Mercantile wrote:
On 10/29/20 2:16 PM, Edward Hernandez wrote: On Thursday, October 29, 2020 at 12:46:42 PM UTC-5, Fox's Mercantile wrote: On 10/29/20 12:00 PM, Edward Hernandez wrote: Look at you and pony pete working in tandem. You fix that piece of **** charger yet asshole? -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com Hey Gramps. What you mean to say is, "How else can I serve those in this forum community." In other words no. I figured as much. -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com Have you figured out how to be a better person? You don't have to answer. lol. We all know. |
#40
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Battery doorbell local repeater?
On 10/30/20 8:33 AM, Edward Hernandez wrote:
Have you figured out how to be a better person? Only to those that deserve it. You certainly don't. -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
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