The SCR latched when we used an LED instead of a buzzer, but then when we used a buzzer it wouldn't latch until we added the other transistor. Now it latches but the entire thing requires another battery bringing the total to: a kitchen timer, a battery for the other transistor, and a battery for the buzzer. It seems like I should be able to use the same battery to function the transistor and run through it to sound the buzzer.
I'll try to figure out the output from the timer, it shouldn't be much. I'm just running a couple wires from the speaker to the SCR to function it