Hello all,
I have been tinkering with this circuit for awhile and would like any and all advice on it. It is for an electic dead bolt lock. U is from a reciever to lock and unlock. SW1 is the door position. B and C are photo transistors for the position of the lock. E is a low voltage circuit. Like I said before any and ALL advice is greatly appreciated. Thanks again for all your help.
They will work OK except that the pinouts are different and the Set & Reset on the 4013 is active high vs active low on the 74HC74. You'll have to change R7&R8 to pulldowns and connect the common of SW1 to the 9V supply instead of ground. I would also add a 10K resistor to the collector of Q1 to limit the base current into Q3.
b_reagle said:
I do not think a smitch trigger is what I want; as battery level falls won't the trigger level fall as well with 4011?
The "trigger level" will change with supply voltage using either the 4011, 4093 or 74C00. If you want a fixed trigger level, use a TL750L05 (Or other LDO regulator) to power the circuit from 5V. You'll have to change Q6 to a logic level FET and U3 (Connected after the TL750L05) so that it triggers at apx 4.5V.
I think the motor is 9V, but then you could also use a lower voltage motor. But that may draw too much current and a regulator will keep some of the motor noise out of the digital circuitry.
The (right)chips and everything else should be good until at least 10vdc, even more. I was thinking maybe 4 AA(6vdc) depends on the motor(still debating). I have one of the kids rc cars ripped apart for right now. The very important part is low voltage. I want to get back in...