View Single Post
Old 06-05-2009, 03:09 PM
Michael John Nunnerley's Avatar
Michael John Nunnerley Michael John Nunnerley is offline
Gold Member
Join Date: May 2008
Posts: 1,193
Circuit Not Tested

Here is the circuit, which I think will need more work with experimenting. How it works is the heating coil and C1 is an LC circuit, the pick up coil controls the mosfet at the frequency of the oscillation of the LC circuit, VR is for the set point of the mosfet. Between VR and the positive rail should be a resistor of about 10K, which is not shown, to protect the mosfet. When the mosfet is off, C1 supplies the current, when on the battery supplies the current. There is no switching of polarity on the heating element coil, no diodes are needed.


Attached Images
File Type: jpg self oscillating circuit.jpg (35.0 KB, 280 views)