Electronics 2000

Hi,

It's about twenty years since I last dabbled in a hobby micro electronics project and I'm really rusty + I'm sure technology has moved on a bit since then.
I'm hoping someone will be able to give me some advice on the following project.

I have this small wooden kit:



...which I wish to drive/motorise with this 1.5-3V gearbox/motor combination...



...using a timer like this one as a control circuit.



Ideally I want to make it battery and mains powered (one or the other, not both at the same time). The idea is that the finshed article will be an idle curiosity that can be started, stopped or will stop on its own after, say, thirty seconds. The reason I want to use a battery of cells is I don't want to have to plug it in.

My problems / questions are as follows:
1. Is there a lower power timer circuit that does the same [exact] job as the one above? I'm trying to keep the number of cells down if possible.
2. The timer documentation states that it requires a 12V 'regulated' supply. What does this actually mean? Will it work with eight 1.5V double-A cells?
3. If I use a 12V regulated supply like this one how would I 'tap' a 1.5V supply for the motor?

I'm sure there will be other questions but I think that's enough for now.

Thanks,

Zulu

1. If you want to keep the number of cells down then the 12 V relay seems to be overkill. The relay switches 2 amps at 230 VAC, but the motor only needs 1.5-3 V. The 555 timer IC on the timer PCB will run on 6 V.

2. 12 V regulated supply means that the output voltage stays the same regardless of the load connected to the supply. The speed control in cars are mostly unregulated, i.e. when you drive uphill, the speed drops unless you push the pedal. A cruise control is a regulated system - the output/speed stays the same. You just have to stay within the specified load (amps or grade).
The timer datasheet says 55 mA which would probably be supplied by most batteries, but it depends on the specific type how long it would run. Do you have a specific type of battery that you want to use?

3. You can regulate the voltage further down with one of these:
http://www.maplin.co.uk/lm317-3-termina ... ators-8067