low frequency joule thief

low frequency joule thief built using a standard Xformer instead of a toroid. the transistor is 2n3771, the low frequency(60-70 HZ) allows you to light a CFL with the ballast intact. the CFL is rated at 23 watts, the power consumed by the circuit is 25 watts. it will also light a 25 watt incandescent. the output is roughly 120 volts. the schematic is identical to the toroid based joule thief circuits seen all over the web, the only difference is the non toroid xformer, the same circuit will work with standard 10:1 transformer with center tap. the base resistance is 10k, the base to ground bias is 3k. you can put a 10K pot on the base with a 5k resistor to adjust output power to suit the application and maximize efficiency. the output in this design is connected to the positive input terminal and the base of the transistor at the transformer (before the resistor). the battery is 12 volts. the capacitor is not needed, but i found it helps to stabilize the frequency.
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