Re: (ET) Speed / power drain / reverse problems C185

[Christopher Zach <cz alembic crystel com>]

On 8/20/2012 10:56 AM, Biophiliac wrote:
> Chris,
> Thanks for your response.  There appears to be two cards, a diode assembly 
> and diode varistor assembly and a field resistor. The diodes all visibly 
> look ok, although when I replaced the varistor which was originally broken 
> / blown.
>
> If these are the cards, can I easily test them for integrity? Or should I 
> just replace one or both ? Do you know which one is likely causing my 
> speed control problem?

Sure. Just test the diodes with a diode tester or meter. The four on the 
bottom right of the board are normally what fail, most of the rest of 
the board is for the field weakening control.

If the motor has no field, this could be the cause.

Chris


> Jef
>
>
> Chris Zach <cz alembic crystel com> wrote:
>
> > On 8/16/2012 1:18 AM, Biophiliac wrote:
> > > CZ,
> > >
> > > Forgive my ignorance / inexperience.  I've heard talk about these cards 
> > > and I don't see anything visibly under dash panel resembling a card 
> > > (printed circuit board?) or on the detailed wiring views of my worn copy 
> > > of C185 1975 parts manual.
> > >
> > >    So my question is where is card 2 located and will diodes be visibly 
> > > blown and/or can I test them with a basic multimeter?
> >
> > If the C185 is basically the E20, then the card is located on the
> > firewall, right size. The Four diodes on the bottom left control power
> > to the field, sometimes they blow up so you get reverse but not fwd and
> > such.
> >
> > Chris
> >
> >
> > _______________________________________________
> > Elec-trak mailing list
> > Elec-trak cosmos phy tufts edu
> > https://cosmos.phy.tufts.edu/mailman/listinfo.cgi/elec-trak