Hi Everyone,
Looking for some assistance driving an eddycurrent retarder.
My Skills - I have some basic soldering skills and some limited understanding of circuits and their components. Enough to build a timer circuit with Resistor/capacitor and understand basic logic chips jk flipflop ..etc Not enough to build a circuit that uses them. I can write software in many languages.
Essentially I have a very old Dyno for tuning race cars. It has a retarder in it.
This is connected to a slotted disc (12 slots read by optical circuit (Sensor).
This connects to a torsion spring.
This connects to another slotted disc and sensor.
This connects to the roller that the wheels go on.
The current circuit boards used a lot of old chips (1980's) that would measure the rotational speed of 1 disc. It would use the jk flipflop chips to determine the difference in position between the 2 discs. With that information is calculates speed and torque. It feeds a speed signal to a second board that drives the retarder to limit the speed in a desired range.
All the boards are fried so I have purchased an arduino and programmed it. I calculate speed and load based on the input sensors and send a PWM signal output with my desired load for the retarder. This is where I need help -
How do I drive the retarder with my PWM signal? I have approximately 40v coming from the existing transformer. As per the attached pic there is a small circuit board that sends 2 signals to 2 plates (On the left) each plate has
diode and a triac/SCR 2N3898. The SCR connector goes back to the main driver board on the SKA connector. The 2 signals are fed from the 2 resistors just to the right of that and the source of the resistors is the same rail.
So I hope that's enough for someone to understand what's going on. I have purchased one of these in the hopes that it might be what I need. I basically need to know how to take my PWM output from my arduino and drive the retarder through the small circuit board or directly to the plates. I can wire, I can solder. I just can't design the circuit.
Thankyou for any advice. An entire club of race car drivers would sincerely appreciate your help.
BTW we are only driving 1 coil on the retarder.
Looking for some assistance driving an eddycurrent retarder.
My Skills - I have some basic soldering skills and some limited understanding of circuits and their components. Enough to build a timer circuit with Resistor/capacitor and understand basic logic chips jk flipflop ..etc Not enough to build a circuit that uses them. I can write software in many languages.
Essentially I have a very old Dyno for tuning race cars. It has a retarder in it.
This is connected to a slotted disc (12 slots read by optical circuit (Sensor).
This connects to a torsion spring.
This connects to another slotted disc and sensor.
This connects to the roller that the wheels go on.
The current circuit boards used a lot of old chips (1980's) that would measure the rotational speed of 1 disc. It would use the jk flipflop chips to determine the difference in position between the 2 discs. With that information is calculates speed and torque. It feeds a speed signal to a second board that drives the retarder to limit the speed in a desired range.
All the boards are fried so I have purchased an arduino and programmed it. I calculate speed and load based on the input sensors and send a PWM signal output with my desired load for the retarder. This is where I need help -
How do I drive the retarder with my PWM signal? I have approximately 40v coming from the existing transformer. As per the attached pic there is a small circuit board that sends 2 signals to 2 plates (On the left) each plate has
diode and a triac/SCR 2N3898. The SCR connector goes back to the main driver board on the SKA connector. The 2 signals are fed from the 2 resistors just to the right of that and the source of the resistors is the same rail.
So I hope that's enough for someone to understand what's going on. I have purchased one of these in the hopes that it might be what I need. I basically need to know how to take my PWM output from my arduino and drive the retarder through the small circuit board or directly to the plates. I can wire, I can solder. I just can't design the circuit.
Thankyou for any advice. An entire club of race car drivers would sincerely appreciate your help.
BTW we are only driving 1 coil on the retarder.
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