Power Amplifier with 2N3055

Simple and low cost. The optimal supply voltage is around 50V, but this amp work from 30 to 60V. The maximal input voltage is around 0.8 – 1V. As you can see, in this design the components have a big tolerance, so you can build it almost of the components, which you find at home. The and transistors can be any NPN type power transistor, but do not use Darlington types… The output power is around 60W.




Some comments:

- capacitor C1 regulates the low frequencies (bass), as the capacitance grows, the low frequncies are getting louder.

– capacitor C2 regulates the higher frequencies (treble), as the capacitance grows, the higher frequencies are getting quiter.

– this is a class B amplifier, this means, that a current must flow through the end transistors, even if there is no signal on the input. This current can be regulated with the 500? trimmer resistor. As this current incrases, the sound of the amplifier gets better, but the end transistors are more heating. But if this current decrases, the transistors are not heating so much, but the sound gets worse…

copy from : http://www.electronics-lab.com/projects/audio/042/index.html

12V LED Flasher for Cars

This is so wonderful circuit diagram Because you can up grade the out look of you car or van by using this simple circuit .Actually this is a blinking Led circuit on the other hand this circuit is called multivibrator circuit.The impotent thing of this circuit is this circuit can be operated with 12V power supply


source : http://freecircuitdiagrams4u.blogspot.com/2010/07/12v-led-flasher-for-cars.html