So I'm working on a keypad lock that a buddy of mine wanted me to do for him and I designed it so that I could use what materials I had laying around. Once I began working I noticed that I lacked a SR latch. However, I do have a JK flip flop. Would it be possible to substitute? The JK flip flop in question is the MC14027BCP. Thanks in advance.

 

It should work. See our Ebook and the truth table for a J-K FF - http://www.allaboutcircuits.com/vol_4/chpt_10/6.html

 

Sure, just ground J, K, and Clk, and the then use PRE and CLR as the Set and Reset, respectively.

 

Keypad lock eh, neato. We had to design something of the sort for an exam along with 8 other problems in 1:15. Needless to say, almost nobody succeeded. If given enough time you can build anything, but 1:15 come on now.

 

Thanks. I must say this forum is incredibly helpful. Anyways, now that I know that it will work might I get one of you helpful lads to look over this schematic for me? I've yet to test it, so I might as well go ahead and post it so I know I won't be wasting my time. Mind you my schematic rendering skills are not the best.

The transistor is just one I chose by the way. The program didn't have the ones I've got lying around.