Hello gang, I'm kind of stumped here. I put together a tiny little one transistor crystal oscillator. It's keyed by grounding the emitter and it works. So I decided I'd key it using an arduino micro controller and send some pulses to it via a 2N3906 transistor.
I would then tie the arduino LED pin via a 1K resistor to the base of the 2N3906. It works, my system voltage is 7.2 volts and the arduino is clearly sending turning the transistor on grounding the emitter of the oscillator I get morse code.
But when I up the entire system voltage to 12 volts, immediately the circuit begins oscillating. It's not drawing full current mind you only 10mA as opposed to the saturated 50mA, but it's turning on. I can't seem to figure out why, but it's as if the collector emitter junction is allowing current through regardless if the base is tied to ground or biased.
Thanks,
Pat
I would then tie the arduino LED pin via a 1K resistor to the base of the 2N3906. It works, my system voltage is 7.2 volts and the arduino is clearly sending turning the transistor on grounding the emitter of the oscillator I get morse code.
But when I up the entire system voltage to 12 volts, immediately the circuit begins oscillating. It's not drawing full current mind you only 10mA as opposed to the saturated 50mA, but it's turning on. I can't seem to figure out why, but it's as if the collector emitter junction is allowing current through regardless if the base is tied to ground or biased.
Thanks,
Pat