|
Today was my first commute in the eBooger. It was a smashing success.
12V is not enough for the field in my sepex motor. Too little start off torque and it has to rev much too high to make decent power - the shift from first to second at 6000+ RPM. Plus, I can hear arcing brushes at higher revs. As soon as I switch to 24V field, the brush crackling sound goes away.
I measured field current today. It turns out that the field windings are 1 ohm. 12V = 12.5A, 24V = 25.0A.
I still have a major problem with a massive voltage surge from the field whenever the relay goes open. I tried to eliminate it with a large(ish) diode across the field terminals, which helped, but it's still there. When the field relay opens on 24V, the arcing lasts a few seconds and the relay gets smoking hot after a few on/offs.
I decided to run pin 87a of this relay to ground so the field surge goes straight to ground. At 24V it seems to have cured the arcing. However, when I tried 36V on the field, as soon as the relay opened sparks flew, and stink filled the air. Not good
What do I need to eliminate this voltage spike completely? What resistors, capacitors, diodes, etc. do I need and how do I do it?
How many amps can I safely give the field?
|