[Oeva-list] Should I use an intermittent contactor or a continous for the starter?

barnes.rick at verizon.net barnes.rick at verizon.net
Fri Sep 22 17:55:08 PDT 2006


I think you should use a continuous duty cycle rated coil. It will be energized the whole time you are driving your car, right? An intermittant duty cycle rated coil may get too hot.

Here is a description I found:
"Duty Cycle – The duty cycle of your application is the ratio of the "on-time" divided by the total time for one complete cycle (on + off).  Duty cycle is usually expressed as a percentage or a fraction (50%, 100%).  A more simplistic representation of duty cycle is to call < 100% duty solenoids "Intermittent" and 100% duty cycle solenoids "Continuous".  All intermittent duty solenoids (< 100% duty cycle) also must have a maximum "on-time" allowed to avoid overheating that can eventually lead to a burned out coil.  The "on-time" must not exceed the power dissipation limits of the coil.  Proper heat sinking and/or additional cooling improves heat dissipation which allows a broader duty cycle range.  Very close attention must be paid to the maximum "on-time" data provided in conjunction with the duty cycle calculation to avoid damaging your solenoids.  For example, although an application with a one hour cycle time and a 3 hour off-time might calculate to a 25% duty cycle, this is not realistic in practice. A more realistic solenoid application might be an on-time of one second and an off-time of 3 seconds for the same 25% duty cycle."

Rick Barnes
Aloha, OR

From: Adan Vielma <vielma at lclark.edu>
Date: 2006/09/22 Fri AM 10:40:58 CDT
To: oeva-list at oeva.org
Subject: [Oeva-list] Should I use an intermittent contactor or a continous	for the starter?

Hi!I recently was doing some research into the component design for an ev and have a question on contactors. For the starter contactor, basically the one that when you turn the key it is activated so that the battery pack power is now connected to the motor controller, would you use an intermittent coil-type contactor or a continuous coil-type one? The item I'm looking at is the SW-200 Single Pole Single Throw, Normally Open contactor from:http://www.tecknowledgey.com/catalog/product_info.php?cPath=57_61&products_id=530 They said they only have the continuous coil-type in stock and not the intermittent. I was a bit confused as to which coil-type is used in normal EV conversions for the starter or other contactors. If you can answer this question, I'd be more than happy.Thanks so much!Sincerely,Adan Vielma

Oeva-list mailing list
Oeva-list at oeva.org

More information about the Oeva-list mailing list