Voltage regulator question
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Bellerophon
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Zener Diode Voltage Regulation?
Anybody ever user Zener diodes? That's apparently what PL uses on their TOS E 1/350 lighting kit.
http://www.starshipmodeler.net/talk/vie ... 73&start=0
http://www.starshipmodeler.net/talk/vie ... 73&start=0
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Bellerophon
- Posts: 2548
- Joined: Fri Oct 16, 2009 10:00 pm
- Location: 13 miles southwest of Grovers Mill
- Contact:
I just got a bunch of 3.6V zeners for like a penny apiece, but haven't tried using them yet. Soon as I do I'll post something here. 3.6V is good for a lot of green, blue, UV, and white LEDs.
As I understand it, you put the reverse biased zener in parallel with the LEDs it's controlling the voltage for, all in series with a resistor sized to get the desired voltage drop for the amount of current drawn by the LEDs plus the zener. It should take a trickle of current to get the zener to do its thing, but it can handle more current without much change in its voltage drop.
So if the limiting resistor is too small, too much current will pass but the zener will let the excess through without its voltage going up significantly, so the LEDs are protected. Likewise if the line voltage to the resistor is too high. All within limits, of course.
As I understand it, you put the reverse biased zener in parallel with the LEDs it's controlling the voltage for, all in series with a resistor sized to get the desired voltage drop for the amount of current drawn by the LEDs plus the zener. It should take a trickle of current to get the zener to do its thing, but it can handle more current without much change in its voltage drop.
So if the limiting resistor is too small, too much current will pass but the zener will let the excess through without its voltage going up significantly, so the LEDs are protected. Likewise if the line voltage to the resistor is too high. All within limits, of course.