Admittedly, flip-flops are not my thing, but from what I read in the datasheet, I don't understand why this isn't working. I am building a sensor that will turn a hall light on when I go in one of two doors and back off when I exit one of two doors. A IR LED shines in an IR photodiode, which triggers a 555 in monostable mode for an on-period of 2.5 seconds. Here is where things go awry. The output of the 555 SHOULD toggle the flip-flop thereby turning a relay on or off (via an NPN transistor) on each pulse.
The problem is that both Q and Q (I can't do a line on top so...) are staying positive regardless of the clock pulse from the 555. That is keeping both the transistor and the relay turned on.
Can someone please tell me what I am doing wrong with this flip-flop? I have attached the schematic I am using. I could design this using an MSP430, but that is just overkill in my mind, and I really don't like doing things with processors that SHOULD work fine with discrete components.
Thanks!
The problem is that both Q and Q (I can't do a line on top so...) are staying positive regardless of the clock pulse from the 555. That is keeping both the transistor and the relay turned on.
Can someone please tell me what I am doing wrong with this flip-flop? I have attached the schematic I am using. I could design this using an MSP430, but that is just overkill in my mind, and I really don't like doing things with processors that SHOULD work fine with discrete components.
Thanks!