Electronics 2000

Don't get the TTL, I will sort out a different chip and one button. They are bound to press both just to see what happens...bang!

Tar&stuff.

You need 6 NOR gates, either a quad and a duel chips or one chip with 6 gates, and a button which is on when pressed and off when pressed again. Job done one button child proof.

Tar&stuff.

What am I talking about, forget the NOR gates, you will need a 555 timer and a clock input.

If you want the circuit let me know and I will do it, I will need read a chapter in my book, that will take hours.

The two button circuit will work but I will have to do my home work for one button.

I must stop, things to do ... The problem when I do this forum is I start on something and it eats in my mind till I get it done.

£200 per hour.

Tar&stuff.

Aha... You don't need a 555 ureka, I knew it could be done with one button but could not remember how.
Its flooding back, I don't need to set aside hours to re read the book. A JK flipflop is what you need, may be some other gates but simple...simple is best. 1 momentary switch and the flipflop toggles ah ha ha har, my brain can relax at last.

Back tonight.

Tar&stuff.

Hi, I need to know if the 4V output is a pulse or a constant 4V, if you put a multi meter on the 4V output from the stop circuit, +on where it says 4V and minus on the minus side of the battery. Tell me if you get 4V with the door closed or not.
If it is a pulse you will not see it on the meter.
I think 3 JK flip-flops will do it but two will need to be pulse triggered.
There is probably a single chip to do that.

Tar&stuff.