Layout for 20w Stereo Amplifier Circuit
This circuit with a 12V supply, the largest voltage variation of a conventional amplifier solid state can generate is ± 6V. The result is a lean 4.5W RMS 4o and 2.25W RMS 8O, without loss of output transistors. Even if the current supply is about 14.4 V (the maximum that can normally expect a 12V car battery) which provides only current ratings up to 6.48W and 3.24W and 4o loads respectively – still not really enough.
There are three common solutions to this problem. The first is to increase the supply voltage switch-mode DC converter. This dramatically increases the cost and complexity of the amplifier, but it is a way to get a lot of 12V. However, we wanted to keep this simple project, which excludes this technique. Be varied by adding method, as the architecture of H-class blade holders used in this IC TDA1562Q PA Amplifier (silicon chips, February 2003). It can achieve 40W/channel but> 0.1% THD. In this case, the output of the amplifier itself provides the fuel pump switch. Another way is less impedance. Car speakers have an impedance lower than 2O, which allows twice as much power transmitted in the same supply voltage.
S:freecircuit.net
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