TDA7294 Car Subwoofer Amplifier Circuit TL494 DC to DC Converter

Probably the most sold TDA7294 integrated amp bass amp became one of the TDA7294 this application even though the car is designed to be used in part thanks to the TL494 controlled SMPS circuit 12v battery voltage symmetrical entered as 2x40v upgraded.

To take full advantage of integrated TDA7294 supply voltage selected at the highest level, but you get the information you want a good cooler cooling fan must be connected even on the circuit TL072P also filter op amp has adjustable bass frequency. EI33 transformer SMPS used in section 1 and section input output coil windings 2 × 2 × 5 laps 14 laps the car amp pcb design of the project, the layout is very stylish worth doing

DC DC converter TL494 (KA7500) is made with PWM control integrated circuit. There is overvoltage protection, if the voltage exceeds 15V, the driver is turned off. The circuit also has low voltage protection, in case the vehicle battery is discharged, the driver is turned off when the voltage drops to 9V and below. The current protection section provides general safety of the switching transistors and the entire circuit.

If the switching transistors are loaded more, a higher voltage is obtained on the IN + value of the structure in the comparator. This is measured with a simple circuit consisting of a 1N4148 diode and an RC (10K, 10n) filter. IN-, you can adjust the comparative voltage with the PR1 potentiometer, and if the voltage on IN + exceeds the set value, the driver is turned off. The green diode means normal operation, and the red diode means that one of the protections has disabled the driver. Soft start circuit prevents the converter from starting slowly and the large-capacity capacitors at the output from suddenly charging

TL494 Switching frequency is 50KHz, which is suitable for ATX / AT transformers. Low frequency causes the transformer core to heat up. If you are using your own transformer, you can lower the switching frequency to reduce the losses in switching. For example, you can change the frequency by installing a larger capacitor on pin 5 of the driver. 1nF gives about 50KHz frequency, 1.5nF gives 30KHz. If the DC DC Converter is working properly, changing the transistors does not require any additional cooling. IRFZ44N can provide up to 300W power.