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Tuesday, November 27, 2007

33 Volt DC to DC Converter

33 Volt DC To DC Converter

Description: 33 Volt DC To DC Converter

This is the right solution for your MOSFET based low power linear amplifier if you have no AC source in your house and have to rely on battery. Generally IRF MOSFET transistors require DC supply at least 24 to 36 volts for efficient operation and their output power drops drastically when the supply voltage is only about 12 volts. The dc to dc converter described here is very simple and enables you to apply 33 volts to IFR transistors from your 12 volt rechargeable battery. Another advantage is that you can reduce the size of your power transformer if you are working on mains. It will also come handy for field days when you have to depend on battery for operating your rig without mains supply. A pair of 2N3055 , work as an oscillator at high frequency and the higher voltage appearing across the secondary of the oscillator coil rectified and filtered to get 33 volts dc. The oscillator coil is wound on 30 mm diameter toroid, which is available easily anywhere .Two of them are used after fixing them together with quickfix. The primary containing 9+9 turns is wound with 20 awg enameled copper wire and the feedback winding 4+4 turns is wound over it. The secondary is wound using 22 awg wire, about 36 turns. This power supply should be switched off, when receiving as otherwise , it may produce noise in receiver. Four numbers of high speed switching diodes BA 157 and 1000 mF/ 50 volts filter capacitor produces 33 volt DC. The usual rectifiers diodes are not suitable here because, the voltage is at high frequency. The two transistors [T1 and T2 ] are mounted on a heat sink it is found that the transistors get only slight warm during transmission.

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