On Thu, 22 Sep 2005 08:17:08 -0400, "Doug Dotson"
dougdotson@NOSPAMcablespeedNOSPAMcom wrote:



Looks like it is a potted module.


What does it look like and are there part numbers or ID
on it? How many connections for large wires are there?
Is there another identical unit in the controller area?

This sounds like a solid state relay. With a DC thruster
motor there are two basic options. One is to use a DPDT
relay or two SPDT relays. The principle is to apply + & -
battery for one direction and opposite polarity across the
motor for the other direction.

A SPDT relay will have two big connections and two small ones.
A DPDT relay will have two big connectons and three small ones.
It would seem that using two SPDT relays is the proper way.
Otherwise, battery power is applied to the thruster at all times.
So there would have to be another single pole relay to shut off
power when not being activated. The most straightforward approach is
a bridge connection. This requires four modules (only). What kind of
setup does it look like you have?

The small connections are the control lines. Depending on
current rating, a replacement should be in the $15-$25 range.


Gary Gaugler, Ph.D.
Microtechnics, Inc.
Granite Bay, CA 95746
916.791.8191
gary@microtechnics dot com