In my (now) continuing series on making stuff out of an old TV I wanted to show you next step I took.
Having tested the driver I made in an earlier post with a 12v battery it became apparent that I needed to create a much higher DC power source. Luckily I had a variable transformer and so I just needed to add a full bridge rectifier and some smoothing caps (again taken from the old TV I bought from Goodwill).
The full wave rectifier is a simple design taken from the Naudin page – I had to buy the 2N3055 power transistor from Radio Shack, but since I had the variable transformer I decided that it wasn’t needed.
The light bulb was put in series with the AC input to limit the current being fed into the circuit – please note that light bulbs only function as resistors when they are “hot” so there will always be an inrush of current at the start of any test. Ramping the voltage up slowly through the variable transformer helps with this.
Whenever I test anything like this I like to start with a 25W (25W/120V = 0.208 Amps) bulb and work up.