To answer my own question about jumpering pins 8 and 9 on card 1
together,
and what card 1 actually DOES as far as the reverse relay control -
from
the card, it looks like it's a time delay circuit, so that if you
flip
from forward to reverse (or vice versa) too quickly, while the motor
is
still spinning one way, you don't suddenly reverse the field to
point in
the opposite direction. Is that correct? So, the reason I shouldn't
just
jumper 8 and 9 together is so I don't go and reverse the field too
quick,
which would probably give me a big induced current in the field
winding,
presumably frying a connection somewhere - probably on the relay.
Seems like I could do that as a temporary fix (if I need to
wait
for some part to arrive so I can fix card 1), just making sure I
give
plenty of time between going from forward and reverse, to avoid
frying
relays left and right.
I'll check though to see if I can determine what part on
card 1
fried, to see if I can get it working without jumpering across those
terminals (we have gobs of resistors and capacitors at work, so if
that's
all it is, I can "borrow" a 3 cent resistor or cap to fix it).
Mike
--
--------------------------------------------------------------
Michael S. Briggs
UNH Physics Department
(603) 862-2828
---------------------------------------------------------------
On Sat, 5 Aug 2006, Michael S Briggs wrote:
>
> Damn damn damn. Ok, it looks like I have a problem on card 1. With
the speed
> lever in reverse (neutral), I get battery voltage at wire 41
(terminal 8) on
> card 1, but nothing on wire 39 (terminal 9) on card 1. So, card 1
ain't
> working properly. Hmmmm... could I for now just jumper them
together? What
> exactly does card 1 DO as far as controlling the forward/reverse
relay? It
> seems like it just passes battery voltage on to the relay - it
comes into
> card 1 on wire 41, and goes out on wire 39. So, is there any real
need to
> have it go through card 1?
> At any rate, unless someone says it's ok to jumper
terminals 8 and 9
> together (wait, didn't I just see someone say that? Or was that in
the
> archives?), I'll try to find what part blew on card 1. Also need
to determine
> WHY. Did card 1 fail, which then caused the new relay I put in to
fail? Or,
> was the new relay bad to begin with, and due to it having some
short across
> the coil, it caused a failure on card 1. Ah, the chicken or the
egg.... :)
> I'm going to swap in one of the other relays. Mental note
- but parts
> (such as replacement relays) from Harold, instead of cheap Chinese
parts....
> I guess I can also use this opportunity to put in that
shiny new
> capacitor for the charger. :)
> I wonder if I can mow the entire yard with only forward
speeds....
>
> Thanks,
> Mike
>
>
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