PWM Output (analog)
I had was wondering if the unit puts out the PWM signal while bench testing. I use an analog signal for my dyno and I am noticing the output stays at 4.57v always. Even if I "test" the output with the mouse by moving the bar. My guess is that it doesn't test unless it sees an rpm signal. Otherwise I don't know why the software is not varying the voltage on the "0v, out, 5v" connector. Thanks, Andrew
I bought mine in 2017 so I believe my terminals don't exist. So I believe the signal is never getting to the output pin. It must just be the pullup that I am seeing.
I tested where the missing connection was and found the signal.
I had the software at %30 and it gave a reading that was believable, 1.4 volts.
I am not sure if the center pin in the photos will be sufficient as a signal alone. It looks like it had a transistor there at Q1 on my board. I am feeding the signal to an Arduino so it shouldn't need that much current for the analog signal input to the Arduino. I am going to try and just feed the signal from the processor straight to the Arduino brake controller.
Here are some photos that I will update as I get things working.
Here is the Voltage reading from the %30 test with a volt meter. I want to put it on my scope to see the signal but I don't think it is necessary. If someone wants to see the signal, I can post it.
The brake is controlled by the SCR transistors. The part of the board that controls the SCR's was cut out of the original brake controller. It was 90's software and technology so I had no way to interface to the board and control the brake. So I cut the part of the board out that had the SCR circuit leaving the opto isolater open to be controlled by a micro controller. The Arduino finds the zero crossing point of the AC wave going into the brake and chooses when to turn on the brake and at what point. This is done with an analog voltage fed into the Arduino which corresponds to a point on the AC wave for different power output to the brake through the SCR.
This is where I got the idea to control this old Clayton dyno. I didn't want to buy a brake controller, so I took apart the original board and used what I could to make it work, and it finally does. ZeroCrossingVideo
Dyno pulls coming soon.