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Got to hook the controller up to the o'scope in class today. Works like a charm! The pulse width would start to rise as the throttle pot was moved to simulate driving off. The Pulse width signal would eventually max out and cause a fault due to never seeing any current at the current sensor. There were some spikes in the PWM signal waveform at pin 7 of U7 (or at D6), is this normal?
We tried to simulate current draw by wrapping several loops of wire through the LEM, connected to a 25 watt, 1K resistor and hooked this up to a DC power supply, but it didn't work. The most we could push was 7 amps (looping the wire multiplies the current somehow according the the industrial text book). 7 amps didn't even register in RTD Explorer.
The instructor asked what the minimum amperage the controller would detect, but I didn't know. Don't recall seeing that information in the posts here. Does anyone know what the minimum is?
Well, time to assemble the power board now!
Jim
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