Fet selection

Thread Starter


Joined Jan 7, 2010
By using a 555 astable cicuit connected to a FET and bipolar transistor , I want to duty cycle control a high voltage source.
The astable is configured for 50% duty cycle and is used to switch a 12VDC source to the primary side of high voltage transformer.
What is the best transistor and/or Fet configuration to use.
Can someone give me a proposal for the schematic to follow and piece part number to use? The Fet need to drive 2 Amp.
Many thanks


Joined Jul 17, 2007
You should look at Ronald Dekker's Flyback Converters for Dummies page:

I'm assuming that you are using the supply for electron tube/valve plates.

Keep in mind that dealing with high voltage, particularly when stored in large capacitors, can have lethal consequences. If you are new to electronics, stick with projects under 50v for a year or so.