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Old 08-19-2014, 09:07 AM   #5 (permalink)
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Originally Posted by MPaulHolmes View Post
I think it's a good idea. The contactor & precharge relay control on your AC controller just requires a single wire running and returning to the contactor. Either the positive or negative line of the coil. It would maybe add another ohm to the coil, but that wouldn't hurt anything. And I think the coil wires are usually rated for 600v (at least on the tyco ev200), so you wouldn't need to worry about that. I just thought about how an EV200 uses an economizer... That means a high frequency signal on a long wire. I suppose you should twist the wire together as it runs to the controller & back to the contactor if you want the controller to turn it on. Or you could just flip a switch in the car to close the contactor.
Just want to check my understanding of the economizer and how it works.
The economizer is a simple circuit that after the contact closes it basically switches the coil current on and off rapidly. So rapid that the coil doesn't have time to release between cycles and because the current is only on part of the time you get an overall reduction in power usage to maintain the closed contact. yes?

So this on and off cycling means that the wires feeding the current to the economizer is essentially an high frequency signal even though it is connected to a DC source.

If so then couldn't we just put a capacitor across the coil connection to charge when the coil current is off and supply the coil with current when the economizer turns the coil current on? So then the run of wire from the controller at the front of the vehicle is just a DC current. No high frequency signals.
It would mean a slight delay in the economiser opening the contactor when the DC supply is removed, but i wouldn't imagine it to be a lot. Probably only the time it takes for one economizer cycle at whatever frequency it is chopping the DC coil current.

Last edited by Astro; 08-19-2014 at 09:08 AM.. Reason: Spelling, doh.
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