Showing posts with label Transistors. Show all posts
Showing posts with label Transistors. Show all posts

Monday, November 17, 2014

Simple Inverter with Two Transistors

The series below is a simple inverter circuit that will change the voltage of 12v dc to 220v ac, with use drive transistor 32 as its tip.
Inverter circuit is very simple and easy to assemble and is perfect for just starting to learn to assemble electronic circuits, you can use the transformer 2A to produce about 20 watts output. Do not forget to install coolers in its transistors. good luck.
Simple
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Friday, October 31, 2014

Microphone FM Transmitter Wireless Two Transistors Circuit

Microphone
Microphone FM Transmitter Wireless Two Transistors Circuit

Please be warned if operating this circuit might violate the regulation of your country, because this FM transmitter circuit radiate strong radio frequency to the environment. This wireless microphone is very sensitive, pick up every sound in the 20m radius, and transmit the radio signal up to 2 kilometers in open air. The first transistor (Q1) is the pre-amplifier for the microphone, and you can ommit this circuit if you don’t want to transmit the sound picked up by the mic, for example you can can connect your mp3 player directly to C1. The core of this FM transmitter circuit is Q2, a modified Collpits oscillator that the frequency is determined by L1, C4, C6, and the transistor’s internal base-emitter capacitance. The antenna use 1/16 wave length to compromize between the efficiency and the size.

If you want the microphone to be less sensitive, you can replace the R1 by a higher resistor, try 10k or 22k, and this might overcome the feedback problem if you use this wireless microphone FM transmitter for a public address system.
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