I have a device which puts out a 30Hz PWM 5V signal, if the signal is grounded it triggers the device to switch to a different mode of operation.
I need to be able to use that 5V PWM signal to trigger a relay on a common ground without the device knowing that the PWM signal is being grounded so that it does not switch modes.
I have already figured out how to convert the PWM pulse to a solid voltage by means of an RC low pass filter, which I can then use to turn on a transistor to trigger my relay, but of course then the device switches modes as the signal is being grounded. This is where I am currently stuck.
Ideas?
I need to be able to use that 5V PWM signal to trigger a relay on a common ground without the device knowing that the PWM signal is being grounded so that it does not switch modes.
I have already figured out how to convert the PWM pulse to a solid voltage by means of an RC low pass filter, which I can then use to turn on a transistor to trigger my relay, but of course then the device switches modes as the signal is being grounded. This is where I am currently stuck.
Ideas?
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