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Re: (ET) Prefer to back up faster.... E20




That would accomplish what you wish.BUT, and there's ALWAYS a BUT................................the stabilizing series field will effectively weaken the main field, resulting in higher armature current. Keep your sniffer at the ready for the unmistakable scent of warm windings.<G>

BTW when the card edge connector splits, you can suddenly find that feature available. At NO extra cost.An eye opener the FIRST time you make that discovery. :)

RJ

Max Hall wrote:
Oh! Good Question! 26AE20AA

-M

On Wed, Feb 2, 2011 at 1:19 PM, RJ Kanary <rjkanary consolidated net <mailto:rjkanary consolidated net>> wrote:

    What model of E-20 ?

    RJ

    Max Hall wrote:

        I'm a Boston-area guy, so I'm pushing a lot of snow. ("snOMG!"
        "Snowmageddon!" etc.) And I really wish the higher speeds were
        available on my E20 for reverse!

        I'm looking at the schematics, and it seems as if all one
        needs to do to have field-weakening for reverse as well as
        forward is to remove a single conductor on the F&R switch
        (more specifically, the portion of the F&R switch between P5-3
        and P5-2 fed by wires 64 and 22-01) as it is a bypass for all
        of the field-weakining resistors.  It seems as if the
        high-current lock-out of field weakening would still work,
        too,  (FW coil between card 4 pins 13 and 20 is controlled
        partly by voltage across a shunt in series with the drive
        motor) as its circuitry is separate from the F/R stuff.

        So:
        Anyone done this? If so, am I barking up the right tree?
        Anyone know why I wouldn't want to do this? (Apart from
        "backing up fast is scary"...)

        Thanks, as ever, fellow ETers. Boy, am I working my E20 this
        winter... love that machine!

        -Max

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