Friday, April 01, 2011

100 W on the cheap

I spend some time yesterday thinking in today's build up.

Having read a post with schematics of compact fluorescent lamps I thought what could be done with those components.
Searching in components specs I noted that the MJE13001 transistors have an TF of 1000000000mHz so that's qualify them to be used in an HF amplifier, also their absolute voltage rating is in the order of 400V (collector to emitter).
I didn't planed to use the 400V but instead a more conservative 110V.
I also found that the toroid present in this lamps (first schematic on the site referred) it's similar to those used in broadband transformers (type 43 material) so will be used also.

Remember that voltages present could be lethal so take absolut care building this stuff.

Here's the schematic:

You should absolutly place a bandpass filter since transistors are working near saturation ence increasing harmonics.
Also place a a cover in the assembly before firing the power because they will get a little, just a little bit hot.... also usefull to remove hardware interferences :)
you can reuse the 1 Ohm resistor from the lamp and place them in the emitter of each transistor, reducing a little bit the output power to around 50W according to my readings.

So here you have from 5W to 100W with a light bulb and 2 power transformers!

Photos of the prototype will be placed tomorrow since I run out of cell phone battery. that allways hapens to me in April first.


Julian said...


PE4BAS, Bas said...

Hi Ricardo, really great idea to use a normal bulb into your idea. You forgot one thing, you can only build this on April 1st otherwise it will not work. 73, Bas