Induction heater magnetic field measurement

Thread Starter


Joined Mar 1, 2006
Hi, I have a 200 kHz tank circuit/induction heater comprising a capacitor in parallel with a copper coil. The coil is tapped and goes to a MOSFET drain. The resonance is achieved using a signal generator to the MOSFET gate which controls the drain-source current. The current is supplied by a DC power supply to the tank circuit.

I need to measure the magnetic field in the coil and think there are two methods (the frequency is too high for Hall type magentic field measuring instruments).

a) measure the current in the tank circuit by inserting a resistor and measuring the current across it - but where to put the resistor, and how is the current value converted to magnetic field?

B) insert a sense coil (small coil) in the main coil and measure the voltage across the end of the coil on an oscilloscope.

I would very much appreciate any help or advice with measuring the magnetic field in the coil (
I'm not an electronics expert by the way)

Thank you