DANMAS@aol.com wrote:
> There are actually two coils in the OD solenoid -- One heavy duty coil to pull
> the solenoid in place, and another lighter duty coil to hold it in place after
> it has been pulled into place. The heavy duty coil draws a LOT of current.
> Once the solenoid has actuated, it operates a switch which disconnects the
> heavy duty coil, leaving only the low current drain holding coil energized.
> This switch is a common failure point. Anytime you switch an inductive load
> (coil), the switch contacts take a beating. A diode would probably help, but
> it would have to be a humongous diode for this application. I don't have hard
> data, but I have been led to believe that the larger coil draws as much as
> thirty amps!
This is an arrangement similar to that used by Bosch for their
mechanical fuel injection fuel cut-off solenoid, and, the draw for the
pull-in coil is quite close to that which you describe. Hold-in coil
current is about 8 amps. Because of the nature of use, it's easier to
wire, since Bosch leaves it up to the OEM to decide the switching, as
the coil has three wires, power to the pull-in, power to the hold-in and
a common ground. Typically, these are operated through diode-suppressed
relays, with pull-in operated through the start circuit and hold-in
powered by the ignition circuit. Not an application which would work
with the o/d solenoid, since it is switched in and out while ignition
circuit is operating. However, with a time delay n.o./n.c. relay, one
might be able to eliminate the internal switches of the solenoid....
Cheers.
--
My other Triumph runs, but....
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