I'm trying to control a high voltage device using a microcontroller but I'm having interference problems.
(Basically I am feeding a control signal to this PWM so I can switch it on and off. The PWM is driving an ignition coil.)
It is running from a battery so there is no proper earth point. If I do connect the battery negative to earth, everything is fine, but if not earthed, the microcontroller will misbehave (triggering inputs) as soon as the high voltage circuit comes on.
I have lots of decoupling capacitance near the microcontroller, and a choke + regulator between it and the supply.
I assume there is a lot of noise on the -ve (GND) rail which is common to both the HV and the controller circuit.
Without actually earthing the circuit, is there a way to keep the noise away from it while still using a single battery supply?
(sorry for typo in title: It should be "Isolating")
(Basically I am feeding a control signal to this PWM so I can switch it on and off. The PWM is driving an ignition coil.)
It is running from a battery so there is no proper earth point. If I do connect the battery negative to earth, everything is fine, but if not earthed, the microcontroller will misbehave (triggering inputs) as soon as the high voltage circuit comes on.
I have lots of decoupling capacitance near the microcontroller, and a choke + regulator between it and the supply.
I assume there is a lot of noise on the -ve (GND) rail which is common to both the HV and the controller circuit.
Without actually earthing the circuit, is there a way to keep the noise away from it while still using a single battery supply?
(sorry for typo in title: It should be "Isolating")
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