Nismo280zEd Posted February 26, 2010 Share Posted February 26, 2010 So today in my EC class we did a lab with a basic amplifier circuit. We used a LM741 chip a 10k potentiometer on bypass to control Gain, and some other resistors and a function generator(to simulate the signal). Anyway... we amplified the Sin wave from 325mV up to almost 3V in the circuit. It got me thinking, many people have trouble with the VR sensor (myself included). I was thinking I could use a similar circuit to amplify the signal from the sensor during cranking. My thought though, once the car is running and say high rpm 5K or above, the VR sensor will put out a good amount of power. Does the MS board have a circuit on it already to dissipate the extra power generated from the VR sensor? I wouldn't want to amplify the signal and then blow a component at high rpm. just a thought -Ed Quote Link to comment Share on other sites More sharing options...
mobythevan Posted February 26, 2010 Share Posted February 26, 2010 You will only have a problem if you are amplifying above the voltage that the MS board uses as input. The normal MS board wants 12 volts from the coil for trigger. You could us an opamp like your experiment to amplify the VR signal up to 12 volts and input to the MS board OK. Keep in mind you would need to run the opamp from zero to 12 volts. A lot of opamp circuits work off of positive and negative supply voltages, like -12v to +12v so your output wave has a 24volt peak to peak swing. As long as you run the opamp from zero to 12v I don't see a problem with putting the signal to tach input on a noraml MS board that expects 12 volts from the coil. RPM will not matter for power, kinda of like PWM at that point. At a high rpm you just have a signal that is getting closer to 12volts, at low rpms it averages to a lower DC voltage. Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted March 2, 2010 Share Posted March 2, 2010 The VR conditioner can handle up to around 100 volts. However, keep in mind that if you're amplifying the signal, you're also amplifiying the noise and may not solve anything. Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted March 3, 2010 Author Share Posted March 3, 2010 The VR conditioner can handle up to around 100 volts. However, keep in mind that if you're amplifying the signal, you're also amplifiying the noise and may not solve anything. That's true, I know that car was having all sorts of reset issues I was trying to solve. Now that I'm learning more about circuitry and how to use my scope to help me diagnose/ measure values I might be able to track some of those previous problems down. Thanks for the input guys! I'm a very hands on/ visual learner, being able to apply what I'm learning with my hobby makes it that much easier for me to get my head around. -Ed Quote Link to comment Share on other sites More sharing options...
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