Can anyone diagnose this simple set-reset flip flop circuit?

Question

I've created the following circuit on a breadboard:

http://www.circuitdb.com/show.php?cid=130

I've checked the connections twice but it does not function as it should. I'm using 2 general purpose NPN transistors (PN2222) and have it hooked up to 12V. When power is connected one side lights up brighter than the other, but nothing happens when either switch is closed.

What I was expecting was one LED to be lit and one to be off and that by pressing a switch that side would go on and the other side would be off.

Any suggestions?

Answer 1

circuit is fine, should work. You have a miswire or a bad transistor.

reading your additions, I suspect you have the transistors wired backwards. A 2N2222 in the reverse direction will break down at 6 or 7 volts.  Which hints that you have the C and E swapped.

Answer 2

The first circuit is fine. If the LED does not go off when the switch is closed, then the transistor must either be defective or misconnected. When the base-emitter junction is shorted, a good transistor will not draw any current. So either the transistor is bad, or you are not shorting the base to the emitter because of a miswire. Try taking the transistor out of circuit, and measuring from collector to emitter with an ohm meter. It should read infinity ohms if the transistor is good. Be sure that the positive lead is connected to the collector. Be aware that cheap ohm meters often connect the positive voltage to the black wire (!!).

Answer 3

What it looks like is that the circuit is wrong, both LEDS should be on when the switch is in its normal state (open), when the switch is closed the corresponding LED should remain on, but the transistor will turn off because its biasing voltage has been shorted to ground.