On Mon, 11 Nov 2013 10:49:05 -0600, "Tim Williams"
wrote:

Is J2 the socket for the PIC, or is it going through cables to the PIC
somewhere else?

What are the trace lengths on the loop from Q1 source (ground), to the
nearest bypass capacitor on +12VR, through D5, back to Q1? (Hint: D5 must
be placed at Q1, not at the coil.)

Why? It will clamp a flyback overshoot wherever it is in the circuit.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

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