# Curtis PMC-25 Controller?



## Revolting (Nov 19, 2012)

I got a Curtis PMC-25 controller with my first EV. The car is a JET Electrica, the Escort kind. This is a project car, no installed controller, mixed bag of test batteries. I am testing and charging batteries and cables.

I am not finding much information on this Curtis controller. A search for PMC-25 brings up 25th anniversary information, not controller information.

I saw information on testing a controller with a light bulb. Would that be a good first step?

Is this controller repairable and worth repairing if needed? Is documentation available? Is a PMC-25 usable for this car?


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## Roy Von Rogers (Mar 21, 2009)

Could it possibly be a EVC255, I have one of those in my Zap.

Take a look at this...

View attachment EVC255.pdf


Roy


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## EVfun (Mar 14, 2010)

It is likely a Curtis PMC-25 controller. I know they where the predecessor to the Curtis old 1221 controllers and rarely seen these days. I have no idea what the voltage rating is or how to really test it. How about a nice Curtis 1221 controller? Since they are still available new lots of people can help with them. I think the PMC-25 was discontinued before 1997 as it was considered pretty old when I started working on EVs. I'm pretty sure the old PMC-25 switched at a fairly low frequency which resulted in motor whining at all speeds.


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## Roy Von Rogers (Mar 21, 2009)

Well I figured the PMC stood for Pump Motor Controller, cause that what the EVC255 is.

Roy


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## Revolting (Nov 19, 2012)

Thanks for the replies. I attached some pictures.

It is easy to open the case on this one and it looks clean inside, not corroded or smoked. It has a bunch of transistors on a bus bar or heat sink and some big capacitors. What I take to be the control board is encased in epoxy.

The car looks pretty good for a 1981 model. I hope to run it at 120V. For now I am trying to understand it and find potential problems.

A 1221 would be nice but I'm trying to learn as I go and not solve all of the issues by throwing money at it. Battery costs are going to make it only semi financially viable anyway. It looks like trying to beat a 50mpg gasser after you pay for batteries and charging is not easy.


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## major (Apr 4, 2008)

EVfun said:


> It is likely a Curtis PMC-25 controller. I know they where the predecessor to the Curtis old 1221 controllers and rarely seen these days. I have no idea what the voltage rating is or how to really test it. How about a nice Curtis 1221 controller? Since they are still available new lots of people can help with them. I think the PMC-25 was discontinued before 1997 as it was considered pretty old when I started working on EVs. I'm pretty sure the old PMC-25 switched at a fairly low frequency which resulted in motor whining at all speeds.


Yeah, that's about right. I think Jet used them at 108V. I actually have one, NOS  And I think I have the manual. I'll see if I can locate it.

With something this old I'd worry about electrolytic caps being dry and heatsink grease dried up. If I ever attempt to power mine, I'll start at low voltage and slowly work my way up. I think the manual may have outlined the light bulb test.

Edit: I just found the manual. It is not the PMC-25. It is the older model. Just called the PMC, with 1981 date. Does not even mention Curtis. I noticed it did not look like you photos. It has no fins and a fan mounted to blow air thru it. So, sorry, mevermind.

ps....The manual has a schematic and it appears to use darlington transistors, not mosfets.


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