This car stereo booster uses an LM2896 IC which has two integrated amplifiers. It can be powered with voltages up to 15 volts. The power output is 2.5 watts per channel with an 8 Ω load and supply voltage of 12 volts. Using the bridge tehnique in the circuit gives a power output of 9 watts. The car audio booster can be powered up from 3 up to 15 volts.
The load impedance that can be connected at its output can be either 4 Ω or 8 Ω. The supply voltage and the load impedance influence the output power level. This amplifier circuit is designed as a booster for auto radio/cassette players. The current consumption by maximum power output and a 4 Ω load is 1 ampere.
Car Audio Amplifier Circuit Schematic
Car audio booster PCB layout
Car booster in bridge connection
To wire the booster as a bridged amplifier, follow the instructions:
- Short the input number 2 of the amplifier. This is the input that is connected to the capacitor C14.
- Add the additional capacitor Cx and the resistor Rx to the circuit as shown by the dashed lines in the schematic diagram. These parts were considered during the design phase of the printed circuit and appropriate holes, and soldering points are already available on the circuit board.
- Instead of using 2 speakers, use a single speaker. Connect the speaker to both output lines of the amplifier as shown by the dashed lines in the booster schematic diagram. You can use either 4 Ω or 8 Ω speaker.
- Now, since only a single speaker is connected to the amplifier circuit, you must construct a second amplifier circuit identical to this one if you want a stereo system. The second circuit will work for the second channel.