Hi,
I studied electronics at school many years ago, but I'm a bit rusty to say the least. Hopefully you can excuse my basic questions and probably lack of clarity.
I have two circuits that record video to SD card. Each is
currently powered by a lithium ion battery that outputs at 3.7v, 2.0amps. The actual circuit consumes 130ma
I want to remove the battery and instead power the circuit by taking power from mains powered equipment - one in my dj mixer that has 12v on it's main circuit.
I'd like to power the other from a wall USB charger which is 5v. I know some computer usb ports are limited to 500ma which I suppose could be a problem if the circuit uses more than that?
What would you suggest? I once read a tutorial that showed how to add usb power points to 12v circuits which used a 5v voltage regulator.
Is that a good plan to follow?
Can anyone suggest a voltage regulator that outputs at 3.7v that would be suitable? I found this, which appears to be a variable voltage regulator (not sure how it's adjusted), but has a low max output 0.1amp.
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=6616796
I've also read about the importance of adding a capacitor to the voltage regulator to deal with any fluctuations. Can anyone explain how to decide what size/type of capacitor should be used.
I've also heard that a heatsink might be required for the voltage regulator. Presumably going from 12v to 3.7 will generate more heat than going only to 5v?
Am I on the right path here? Or should I be doing something else?
Thanks!
I studied electronics at school many years ago, but I'm a bit rusty to say the least. Hopefully you can excuse my basic questions and probably lack of clarity.
I have two circuits that record video to SD card. Each is
currently powered by a lithium ion battery that outputs at 3.7v, 2.0amps. The actual circuit consumes 130ma
I want to remove the battery and instead power the circuit by taking power from mains powered equipment - one in my dj mixer that has 12v on it's main circuit.
I'd like to power the other from a wall USB charger which is 5v. I know some computer usb ports are limited to 500ma which I suppose could be a problem if the circuit uses more than that?
What would you suggest? I once read a tutorial that showed how to add usb power points to 12v circuits which used a 5v voltage regulator.
Is that a good plan to follow?
Can anyone suggest a voltage regulator that outputs at 3.7v that would be suitable? I found this, which appears to be a variable voltage regulator (not sure how it's adjusted), but has a low max output 0.1amp.
http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=6616796
I've also read about the importance of adding a capacitor to the voltage regulator to deal with any fluctuations. Can anyone explain how to decide what size/type of capacitor should be used.
I've also heard that a heatsink might be required for the voltage regulator. Presumably going from 12v to 3.7 will generate more heat than going only to 5v?
Am I on the right path here? Or should I be doing something else?
Thanks!
Last edited: