Capacitor choice

[Dave MilbournParticipant @davemilbourn48782]

Tom
The particular diode I mentioned is bi-directional and works very well. **LINK**

Tony
Best to remove them,
Dave

Edited By Dave Milbourn on 27/01/2014 18:41:40

[TelstarParticipant @telstar]

Dave

Thanks for the link, I understand now, bit like semiconductor miniature of the Metrosil surge limiters I was use to. they would be a bit big for models

Tom

[Malcolm FraryParticipant @malcolmfrary95515]

Strictly speaking, there aint no such thing as a dibirectional diode outside of sloppy catalogue writers offices. The device is properly called a transient voltage suppressor, and acts as a pair of zener diodes* in the same pack. The same effect, only probably better, could be got with a pair of actual zeners each rated just above the maximum battery voltage, wired nose to nose. That way, the back EMFs coming from the motor get clamped hopefully before they exceed the voltage rating of the ESC output transistors.

It is quite possible that, using a bit of luck, the TVS, because of its construction, is acting as if it was a low value capacitor. Which effect is winning is anybody's guess.

*zener diodes have the useful property of just sitting in a circuit doing nothing until the voltage across them gets bigger than their rating**, then they switch on and act like a piece of wire. With reverse current, they act as a piece of wire.

**When the rating gets above a certain value, they start being called "avalanche diodes". Cant remember what the threshold is, but the result is the same.

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