Newbie Question/s


New Member
Hi Guys,

I am currently building an LED Chaser which I wish to run off a 14.5V Supply of the Car Battery. I have the code typed up, the LED's ready (with 620ohm resistors), just need to buy a 08M Chip and solder that into the circuit.

I have had a small hunt around but am wondering what voltages these chips work on? Will 14.5V be alright? Also when the PICAXE chip outputs high will it output 14.5V or something less? Also I have seen some talk of voltage regulators somewhere in the forum. Do I need to do this too?



Senior Member
DO NOT put 14V into the picaxe, it will kill it.

Read the manual (link at the top of the forum). Picaxe chips can only handle an absoloute maximum of 6 volts DC. They are designed to run at 3 -5 volts.

You would need to reduce the voltage (with a voltage regulator) and it would probably be better to run the LED's from 5V rather than 12V (so your resistors will be 220 ohm to 330 ohm instead of 620 ohm).

Another pointer, I'd put the Picaxe chip into an IC socket and check all your voltages etc are right before plugging the chip in.



Yes, you WILL need a 5V regulator if powering from 14.5V.

PICAXEs will blow up if you don't.

A VERY recent thread discussed regulator choice.


New Member
The picaxe will need 5V via a regulator eg 7805 or 78L05. Note the pinouts for a 7805 and 78L05 are different. 7805 gives up to an amp and 78L05 is up to 100mA. The latter is probably fine for led work. You can run the leds off the picaxe via 220 ohms. Or if you are feeling keen you can use the picaxe to drive a 547 transistor (2.7k to the base) and then run the leds off the 12V supply. This latter solution is useful if you wanted to run up to 6 leds in series for a brighter display. Perhaps stick to running everything off the 5V supply for the moment - it is simpler.