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Powering a wireless door chime transmitter.

hamer

Feb 16, 2018
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Hi guys,

I have just registered on the forum and I'm not really an electronics techie.
I have a situation with a wireless door chimer transmitter where it seems like the actual transmitter/bell push eats A23 12volt batteries for fun ie a battery lasts about 3 weeks.
I am considering powering the transmitter with a 12 volt power pack but I am wary as to not connect it directly without some kind of simple circuit/resistor in line. Is this feasible and if so, can someone guide me as what I need to do.
I have also read a post on another forum that a guy has substituted the A23 with a 9 volt alkaline battery to a garage door remote control transmitter with favourable effect. Is this method safe as to not damage the transmitter?

Thanks for reading. I look forward to your replies/comments
 

duke37

Jan 9, 2011
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I do not think that a bell push should consume any current when the button is not pressed. Can you measure the current when the button is released and when pressed.

If the device runs on a 12V battery, then a 12V DC power supply will do but make sure it is 12V not way above. Also connect the right way round.
 
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Audioguru

Sep 24, 2016
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What is "a power pack"?
A battery lets the transmitter be portable. A wall wart power supply must be plugged in and does not have a regulated output voltage that might be 18V with the small amount of power used by the transmitter. 18V is much too high.

We don't know if your transmitter will work from a 9V alkaline battery and for how long. Use eight 1.5V button battery cells that are larger than the tiny ones in an A23 battery.
 

hamer

Feb 16, 2018
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I do not think that a bell push should consume any current when the button is not pressed. Can you measure the current when the button is released and when pressed.

If the device runs on a 12V battery, then a 12V DC power supply will do but make sure it is 12V not way above. Also connect the right way round.
Hi duke37, does it not matter what the amperage of the power supply is ?
 

hamer

Feb 16, 2018
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What is "a power pack"?
A battery lets the transmitter be portable. A wall wart power supply must be plugged in and does not have a regulated output voltage that might be 18V with the small amount of power used by the transmitter. 18V is much too high.

We don't know if your transmitter will work from a 9V alkaline battery and for how long. Use eight 1.5V button battery cells that are larger than the tiny ones in an A23 battery.
I'm sorry Audioguru, what I meant is a 12 volt power supply unit. The one which I have has variable settings from 1.5 volts up to 12 volts.
 

Alec_t

Jul 7, 2015
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Sounds like the transmitter is faulty. Can you get a refund?
I have a cheapo wireless bell, but the transmitter battery has so far lasted over a year. The receiver/sounder is intended to take 3 alkaline 'C' cells. They last only 3 or 4 months, so I modded the receiver and now run it from a USB 5V wall-wart.
 

duke37

Jan 9, 2011
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The current demand will be low if designed to be run from a battery, you ahould measure it.
Almost any power supply will be able to provide 1A, just make sure the capability is above the demand.
 

hamer

Feb 16, 2018
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It's well out of warranty now Alec so I will go with the 12 volt power supply Idea.
 

hamer

Feb 16, 2018
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The current demand will be low if designed to be run from a battery, you ahould measure it.
Almost any power supply will be able to provide 1A, just make sure the capability is above the demand.
Thanks duke, I will give it a go
 

dave9

Mar 5, 2017
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I'm sorry Audioguru, what I meant is a 12 volt power supply unit. The one which I have has variable settings from 1.5 volts up to 12 volts.
That will probably not work, at least all the old supplies of this type that I have seen, are unregulated and vary the voltage based on switching taps on the transformer winding.

The remote is very low current and an unregulated supply would float too high a voltage set to 12V. It "might" work okay set to 9V, but it seems like an unreasonable thing to do, given how common that switching regulated 12V PSU are now. You cannot find a switching regulated AC/DC adapter that doesn't have more than 10X as much current as needed, but that is fine so long as it is regulated.

However it should not eat a battery in 3 weeks. I happen to have a remote doorbell that also takes A23 12V battery and it lasts a couple years. Ironically I just bought a couple more batteries for it, a 2 pack on eBay of major brand cells was $3 delivered.

My indoor receiver takes (2? IIRC) C cell batteries while I instead use 2 x AA Tenergy LSD NiMH in C-to-AA adapters. It takes longer to run those down than the remote A23 cell so I just recharge them when it comes time to replace the A23 cell.

You might consider whether your remote has water getting in and that is causing a short circuit or at least a leak. You could scrub off any flux residue with rubbing alcohol and a toothbrush then spray some waterproofing conformal coating on the entire circuit board while the battery contacts are covered. If the circuit board also has a trim pot then I would cover that while conformal coating the rest, then come back once that dries and put a blob of silicone grease over the trim pot.

However if it is aged and corroded over years of use and exposure, the switch on it might be degraded too, could be time to replace it, OR you could mount the PCB inside with the PSU, and run a two lead wire out to where it formerly was, soldered in parallel to the switch contacts on the PCB, where you install a traditional doorbell switch outdoors instead which will tend to be more robust in outdoor weather and keep the PCB indoors where it's no longer exposed to weather, AND being one wall closer to the receiver, will activate it with less signal loss.
 
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