I want to make a amplifier using transistor, now it should have loud sound then earlier circuit given by Audio Guru and i don't want to add ready made chip in it....!!
I want to drive near by 12 inch speaker just for fun or less than this will also work....!!
I have no sketch of it. power supply of 12V or less than this will also work.
I want to drive near by 12 inch speaker just for fun or less than this will also work....!!
I have no sketch of it. power supply of 12V or less than this will also work.
The extremely simple amplifier I posted will be loud only if you hold the speaker to your ear because its output power is very low at only 0.42W like a cheap clock radio. With a 12V supply the output will be a little more but then the small output transistors might melt.
The simple amplifier sounds pretty bad with about 10% distortion when it plays its loudest.
.......its output power is very low at only 0.42W like a cheap clock radio. With a 12V supply the output will be a little more but then the small output,...............
It should drive 12 inch woofer or less will also work, but there should not be any ready made amplifier chip used in it, it can have transistor transformers, darlington,......
7W into 8 ohms is a voltage swing of 21.2V. A simple amplifier will have a peak to peak voltage loss of about 5V so the amplifier will need a supply of 26VDC. If you use a 4 ohm speaker then the supply must be 20VDC. If you use a 4 ohm speaker and make a bridged amplifier then the supply must be about 12.5VDC.
I used simple arithmatic.
A signal that is a sine-wave and produces 7W into 8 ohms has an RMS voltage of the root of ( 7 x 8)= 7.48V. Its peak-to-peak voltage is 7.48V x (2pi) which is 21.2V. A simple class-AB amplifier has about 5V of losses so the supply must be 21.2V + 5V= 26.2V.
I double-checked with the datasheets of two power amplifier ICs.