Reply To: Merc-O-Tronic schooling please

[frankr]

I have a Merc-O-Tronic manual, but don’t have a MOT instrument, so my knowledge is a bit limited. I also have some electronics training. Somebody said that education is what you have left after you forget everything you learned. But some generalities about condensers that you might find helpful:

Capacity. Importance of correct values varies with the application. Very important in a TV tuner circuit. Far less important in an ignition circuit. I’d consider anything within 20% to be ok and it will run fine.

Leakage: Compare to a leaky water bucket full of holes. Water leaking out of the holes is water lost. Electricity leaking through the “holes” in a condenser’s wax paper sheet is electricity (energy) lost. Lose too much energy and the spark produced becomes weaker. Having said that, wax paper/foil condensers are inherently lousy—they ALL leak. It’s a matter of how much you can tolerate. Experience has proven that the condensers we are working with can be pretty durn leaky and still run..

Series resistance: Post mortem examination has shown me that the method used to connect the wire to the foil sheet varies among brands. A poor connection is almost like disconnecting it intermittently. Of condensers I’ve torn apart, OMC are pretty good on that score. Wico condensers I’ve torn apart are crap.

Conclusion: We are far too unforgiving. A lot of them that we throw away will still run.