B
Bill Wayne
- Jan 1, 1970
- 0
Hello,
For a small project, I need to keep current inversely related to a
photoconductor's conductivity. In other words, current can flow in the
circuit when the photoconductor is *not* conducting. Note that the
voltage and current is coming from a different part of the circuit,
like a capacitor or battery. My last plan was to connect a zener diode
to it so that when the current is high enough, the diode would reverse
it's permitted direction of flow and therefore stop the current. When
light is not shining on the photoconductor, it resists enough to drop
the current below the level of the breakdown current.
Then I found out that zener diodes work via voltage, not current. So I
still need to find a way. I understand it's possible by using a couple
of transistors, but I'm not sure how. So, how would I go about either
A) using transistors to solve my problem, or B) using another way?
Thanks,
Bill
For a small project, I need to keep current inversely related to a
photoconductor's conductivity. In other words, current can flow in the
circuit when the photoconductor is *not* conducting. Note that the
voltage and current is coming from a different part of the circuit,
like a capacitor or battery. My last plan was to connect a zener diode
to it so that when the current is high enough, the diode would reverse
it's permitted direction of flow and therefore stop the current. When
light is not shining on the photoconductor, it resists enough to drop
the current below the level of the breakdown current.
Then I found out that zener diodes work via voltage, not current. So I
still need to find a way. I understand it's possible by using a couple
of transistors, but I'm not sure how. So, how would I go about either
A) using transistors to solve my problem, or B) using another way?
Thanks,
Bill