testing a Curtis 144 volt controller for DC series motors

[@BenjaminNelsonX]

A motor controller failing full on can be a scary thing. I had that happen in a car once. That car was also clutch-less, but I repurposed the clutch pedal to be a manual power disconnect. Stomping the clutch instantly killed the power.

[@steveclunn8165]

What a great idea to use the clutch pedal as the emergency disconnect. You've been doing electric cars for a while, I visit your channel every now and then.

[@namenotshown9277]

I would expect a massive spark if directly charging the capacitors....huge spark. Pre-charge is designed to stop that massive spark from inrush current charging up the caps

[@steveclunn8165]

That's what the light bulb is for across the main contractor. It's a Christmas tree light so you can see when the capacitors are charged as the light goes out. Good point though you really need to have that pre-charge resistor of some sort then there's also the question of do you leave it on all the time which will drain a little bit of power from your pack or you have a pre-charge set up which can get complicated if you like.

[@namenotshown9277]

@@steveclunn8165 I've used similar setup, when light goes out its charged, always wanted to make some circuit that reversed that situation, so light came on when charged!

[@steveclunn8165]

​@@namenotshown9277could have the coil to the relay be the charge resistor, and when it's charged the relay would close wish you then could hook up to a light off of the 12-volt. That's a neat idea

[@namenotshown9277]

@@steveclunn8165 interesting idea

[@namenotshown9277]

@@steveclunn8165 it always bothered me my led went out when caps were charged I just used led in series with resistors for precharge. It was only 72volt nom. ebike controller so not much current needed, was sort of neat would take 4 or 5 seconds to precharge. Your sort of looking for a light to come on when things are ready to go, I like your idea.