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Re: Digital VX40B - Multia?



On 4/1/24 13:55, John Klos wrote:
 That capacitor is precisely cut on purpose to give it an exact value.
 That's done with resistors, too, for certain applications.

 Whoa, no.  That is an "arc gap" capacitor, which is a capacitor that has an integral spark gap that shunts high-voltage spikes to ground, usually on signals that leave a board and are expected to have long wires.  (Note that it's right next to an external connector)

 The capacitance is fixed and is not affected by the cut, and the dimensions of the cut determine the breakdown voltage, not the capacitance.

 To be clear, this is an ESD protection component, manufactured this way on purpose, it is not damaged, and it is not a precision component in any way.

 (Disclaimer [or is it a "claimer"?]: I am a design engineer who has designed these components into commercial products, though not for DEC.)

That makes a lot more sense. It's good to learn something new :)

  The day I don't learn something new is the day they put me in the ground!

            -Dave

--
Dave McGuire, AK4HZ
New Kensington, PA



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