Creating a circuit that will replace batteries

Thread Starter

Dave2801

Joined Apr 19, 2017
7
Hi, I was wondering if anyone could offer me advice / guidance on a project that I want to try, the problem I've got is that my daughter collects things called illumi-mates which are small night lights that come in all different types of characters, they are powered by 3 AG13 button cell batteries and at the moment she has about 20 of them, as you can imagine replacing those batteries approximately every 2 weeks is a pain and expensive, what I need ideally is a mains powered adapter with circuitry to deliver 4.5v to each of the lights but also making it safe to be in a child's bedroom. thank you in advance for any ideas
 

Thread Starter

Dave2801

Joined Apr 19, 2017
7
Any usb type phone charger will put out 5 or 5.1 volts so adding a 4001 diode in series will drop it to 4.4 or so. I think everyone has at least one laying around that isn't needed
That would only power one at a time though would it, I was hoping to try and power about 10 on a series circuit
 

Thread Starter

Dave2801

Joined Apr 19, 2017
7
Welcome to AAC!

What are you requirements for portability, trip hazard, and electrical safety?
Doesn't need to be portable as all lights remain in same place, they are on a table located next to a power outlet, and hopefully if they are on a multi volt transformer it should be safe
 

dendad

Joined Feb 20, 2016
3,564
An old cell phone charger would easily power more then 20 of your lights. The coin cells that it would replace do not supply much current.
As Kermit2 says, just add a 1N4004, 1n4007, or similar power diode in series to drop the voltage then power all the lights in parallel (not series) from that.
Try one first to make sure it does not pop anything.
 
Last edited:

Thread Starter

Dave2801

Joined Apr 19, 2017
7
An old cell phone charger would easily power more then 10 of your lights. The coin cells that it would replace do not supply much current.
As Kermit2 says, just add a 1N4004, 1n4007, or similar power diode in series to drop the voltage then power all the lights in parallel (not series) from that.
Try one first to make sure it does not pop anything.
Thanks for you advise much appreciated
 

Reloadron

Joined Jan 15, 2015
5,508
That would only power one at a time though would it, I was hoping to try and power about 10 on a series circuit
Rather than "series" you want them in parallel. The average 5 Volt cell phone charger has an input between 100 and 240 VAC and an output of 5.1 VDC with 700 mA (0.7 Amp) available current. As mentioned place a diode like a 1N4002 in line and that will drop about 0.7 Volt giving you about 4.4 Volts and with even 500 mA you could power a small mountain of these critters in parallel. Not series but parallel.

<EDIT> I see I was slow in typing. :) </EDIT>

Ron
 

Thread Starter

Dave2801

Joined Apr 19, 2017
7
Rather than "series" you want them in parallel. The average 5 Volt cell phone charger has an input between 100 and 240 VAC and an output of 5.1 VDC with 700 mA (0.7 Amp) available current. As mentioned place a diode like a 1N4002 in line and that will drop about 0.7 Volt giving you about 4.4 Volts and with even 500 mA you could power a small mountain of these critters in parallel. Not series but parallel.

<EDIT> I see I was slow in typing. :) </EDIT>

Ron
Cheers, thanks for your help
 

Thread Starter

Dave2801

Joined Apr 19, 2017
7
Rather than "series" you want them in parallel. The average 5 Volt cell phone charger has an input between 100 and 240 VAC and an output of 5.1 VDC with 700 mA (0.7 Amp) available current. As mentioned place a diode like a 1N4002 in line and that will drop about 0.7 Volt giving you about 4.4 Volts and with even 500 mA you could power a small mountain of these critters in parallel. Not series but parallel.

<EDIT> I see I was slow in typing. :) </EDIT>

Ron
Would I need a diode before every light or just one at the start of the circuit
 
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