This article is for those who wants to make their own car amplifier. In this article, I will discussed the car power amplifier in 3 steps : 1.The design of audio power amplifier, 2. The design of DC-DC converter, 3. Miscellenous tips for making car power amplifier.
There are many designs of good amplifier published,solid state (SS) or tube designs. But few have written the design of car power amplifier.
Actually the difficulty of designing the car power amplifier does not lies with the audio power amplifier, but it is more to providing the switching power supply.
As we know, the output power of any audio power amplifier is approached by formula :
P = Vpp2/(8*Rl)
where Vpp= peak to peak supply voltage, Rl is the speaker impedance load. For car voltage of 12Vdc, if we connect it to 4 Ohm speakers we will only have power of 144/32 = 4,5 Watt. Bridging the amplifier will double the power, but will never be more than 40 W.
If we want to make more powerful amplifier, lets say 170 watt at 4 ohm speaker load, we will need supply voltage of 74Vpp, or +/- 37 Vdc. The way to have this voltage from car supply of 12VDC is to make DC-DC converter.
Visit Here for more.