556 dual timer problem

I'd use a transzorb instead of a zener - they're designed to absorb spikes; use one that's rated at about 7 or 8 V. I'd also use an inductor either instead of the R1 there, or in series with it.

I know about transzorbs - at one company where I worked, they had MOVs all over the place, and the service folks were continually going out to replace them, or they'd ship the box to us for warranty repair. Then one day, we discovered TransZorbs, and they worked so well that they issued an ECO (Engr. Change Order) _and_ an EMO (Engr. Mod. Order) to get rid of ALL the MOVs.

With just a zener, I'd see if there are any 5W zeners anywhere. Automotve (and bike) electrical systems are extremely harsh.

Cheers! Rich

gold stuffed somewhere.

from?

Somebody enters it at a keyboard and poof all your money is devalued.

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ain

I got the board back from my friend and I have applied the suggested reset mod. On the bench it works a treat. I'll get the board back to my motorcycling friend and hopefully that will be the cure.

Thanks for the many suggestions - I am now getting into PIC development - and a special thanks to Robert Baer who sent me a PICKit

Cheers

Ian