25-12-2020, 05:52 PM
(This post was last modified: 25-12-2020, 05:54 PM by Geordie McBoyne.)
Many years ago I modified a Mallory vibrator unit so that the switching contacts were replaced by a 555 timer to provide the drive for a pair of FETs. The 555 was set to give a square wave with a 50:50 mark space ratio at 200Hz.
I was put wise to the fact the power FETs have a high source to gate capacitance, typ. 1000pF. The modified unit did work but it wasn't a truly plug-in device so another modified vibrator was made which dispensed with the 555 and the switching contacts controlled the FETs direct.
Geordie McBoyne.
I was put wise to the fact the power FETs have a high source to gate capacitance, typ. 1000pF. The modified unit did work but it wasn't a truly plug-in device so another modified vibrator was made which dispensed with the 555 and the switching contacts controlled the FETs direct.
Geordie McBoyne.
