icedeocampo
New Member
I did some testing... and here are the results:
1. The voltage limit circuit works within 0.2v of the zener diode voltage
2. V at the Collector is 14.xv
3. V at the Base is 2.x
4. Emitter is grounded.
Now everything works perfectly until I put a small load on the collector and emitter....
A small bulb rated at 12v, 18w... what happens is that all of a sudden the transistor dies... and eventually the zener burns too... when this happens.. the bulb also burns out since.. the voltage goes back to the unregulated above 30v.
on the 2nd experiment, knowing that I could burn another bulb... I connected the bulb for a very very short time, a fraction of a second.. and the again the transistor dies.
It seems the sudden load/unload creates a voltage spike that nukes the transistor.
1. The voltage limit circuit works within 0.2v of the zener diode voltage
2. V at the Collector is 14.xv
3. V at the Base is 2.x
4. Emitter is grounded.
Now everything works perfectly until I put a small load on the collector and emitter....
A small bulb rated at 12v, 18w... what happens is that all of a sudden the transistor dies... and eventually the zener burns too... when this happens.. the bulb also burns out since.. the voltage goes back to the unregulated above 30v.
on the 2nd experiment, knowing that I could burn another bulb... I connected the bulb for a very very short time, a fraction of a second.. and the again the transistor dies.
It seems the sudden load/unload creates a voltage spike that nukes the transistor.