Motor Control Circuit

[Andrew Davie]

I notice that there's a motor control circuit listed in the handbook at
http://www.nbtv.wyenet.co.uk/beginners.htm and that this article also mentions the LED and sync separator boards.

The motor control circuit, shown below...



... is not listed in the club shop sales. I'm just wondering... why? Is it out of stock? Before I embark on motor control experimentation (really, I want anything that will work), I though I'd ask for opinions.

[Roland]

Before I embark on motor control experimentation (really, I want anything that will work), I though I'd ask for opinions.

I've not built any of the suggested club circuits - but the particular one you show does seem to be a popular club solution and it certainly does have the merrit of having built in synchronisation (assuming of course you have the sync seperated out already).

Personally I just started with a low value potentiometer (though these can more than a bit hot!) - and rapidly moved on to the following circuit:

http://www.electronics-lab.com/projects ... light/038/

I modified it slightly to use both coarse and fine value potentiometers to give better control. Having said that - the circuit isn't that stable so I doubt I'll build another one like this.

One tip I picked up from the clubshop was to try the LM317 variable voltage regulator. So far I've built a general bench variable regulator which is useful for all sorts of things as well as controlling motor speed. I'm going to build another one with both coarse and fine value potentiometers to give better control specifically for NBTVA use.

The LM317 is cheap and amazingly easy to use - but does (in my opinion) require a small heatsink - even to drive a 200ma cassette motor like I use.



Roland.

[Klaas Robers]

Andrew, these PCBs are designed, but never made. That is the reason that they are not available. The circuit is that simple that you might make it on experimenters board.