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Topic: Battery powered qlocktwo? (Read 1 time) previous topic - next topic

memoi2001

Hi

I've been looking for an excuse to get an arduino and play with one for a while, and then I saw the Qlocktwo.

Not being ludicrously rich I thought "AHA!".
My question being the power supply.

Basicly the circuit's gonna be arduino -> transistor -> leds (at most 27 at a time)

I was hoping to run this of 5V (4AA batteries) so I could stick it anywhere.

Will this be enough to power the arduino and leds (and possibly a DCF77), and how long is this likely to last, I don't really want to have to change the batteries daily.

Any aditionnal advice is also welcome, I haven't done any electronics since 2004 and don't want to blow anything up.

florinc

Powering any LED clock from batteries (4xAA, 2500mAh) may work, but it is not practical, since the batteries will last a matter of days at most (25 hours at 100mA consumption).

memoi2001

Thought as much. Thanks for the speedy reply.

So if I power the clock though usb or mains adapter can I run the leds of the arduino's vin or is the drain going to damage the board?

florinc

Not sure I understand the question.
Arduino can drive the LEDs for QlockTwo same way it would drive a 8x8 LED matrix, with some auxiliary circuitry (shift registers, transistors, resistors). There are lots of schematics around.

memoi2001

Basicly what I meant was can I plug the usb into the arduino and get the power for the leds through it, or does the power supply for the leds have to be independant from the board?

Tyis being my first project in a while I'm hoping to keep it simple and not make a regulator as well.

florinc

One power source (5V from USB) for both Arduino and the LEDs is ok (assuming you are talking about normal, 20mA, LEDs).

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