This is an 250mW RF power amplifier project. This circuit is designed to amplify the output of about 7mW wide band FM transmitters to a final level of about 250mW.

Schematic Diagram:

Component Parts:

R1 ____________________ 10R
R2 ____________________ 470R
R3 ____________________ 47R
R4 ____________________ 120R
R5 ____________________ 2K2
R6 ____________________ 4K7
R7 ____________________ 22R
Q1 ____________________ 2N2369
Q2 ____________________ 2N4427
Q3 ____________________ 78L08

C1, C11 _______________ 10n
C2 ____________________ 220u/16V
C3 ____________________ 33p
C4 ____________________ 47p
C5, C6, C7, C8, C9 ____ 1n
C10 ___________________ 10u/25V
L1 ____________________ 5 turn coil
L2 ____________________ 3 turn coil
L3 ____________________ Ferrite
L4, L5, L6 ____________ RFC

This is a simple bridge amplifier based on TDA7240A. This circuit is designed for car audio system, but you may use this circuit for your small home audio application…

Schematic Diagram:

PCB Layout:

The following is a quad amplifier circuit (amplifier with four inputs and four outputs) based TDA7381. This amplifier is designed for car audio system, but you can also use this circuit for other purposes. This circuit has a design very simple and very easy to build.

Schematic diagram:

Here is a simple and easy to build circuit diagram of a 12V car battery charger:

The above circuit claimed have ability to prevent battery overcharge that make electrolyte lost due to evaporation. This circuit will eliminate the problems by monitoring the battery’s condition of charge through its retroactive control circuit by applying a high charge current until the battery is completely charged. When charging is complete, it turns on the red LED (LD2) and deactivates the charging circuit.

Here’s a circuit diagram of an amplifier that has four input channels and four output channels or commonly called the quad amplifier. Power amplifier is designed specifically for car audio system applications. With a fairly large output power per channel, low distortion and low output noise features; amplifier is suitable for your car simple amplifier applications.

There are only a few additional components outside the IC power, so it will not take a lot of space.

About TDA7383:
The TDA7383 is a new technology class AB Audio Power Amplifier in Flexiwatt 25 package designed for high end car radio applications.