Power amplifier electronic circuits-tube audio rf amplifiers

Electronic Amplifier Circuits-Power amplifier, audio amplifier designs and circuits

April 22nd, 2010

6 Watt Amplifier Circuit

Circuit Description

The circuit diagram of 6W amplifier using TA 7222AP is given here. This circuit uses integrated audio amplifier IC TA 7222AP as its central part. This is a famous and widely used amplifier IC developed by Toshiba. The unique features of this IC make it suitable for amplifier circuits. The features include short circuit protection, thermal protection, high ripple rejection, low distortion, muting function etc. A suitable heat sink should be provided for this IC to operate safely.

12V DC power supply is used for powering this circuit. The audio amplifier IC TA 7222AP can deliver a maximum output power of up to 5.8 Watts to a 4 ohm load if the supply voltage is 12V. This amplifier is well suited for car radio applications because it can operate in a range of voltage, i.e. from 8V to 12V. In order to get maximum desired performance for this circuit, provide separate ground for input and output.

Circuit Diagram

6 watt amplifier

6 watt amplifier

Notes

  • Us good quality Vero board. To assemble components for this particular circuit.
  • The speaker K1 used here can be 4 ohm.
April 22nd, 2010

Simple Pocket Headphone Amplifier

Circuit Description

The circuit diagram of Pocket headphone amplifier has been given here. The core part of this circuit is the operational amplifier IC OPA 134 developed by BURR-BROWN Semiconductors. In addition to this the circuit contains some passive components also.

The IC OPA 134 is used in this circuit as a non-inverting amplifier. High input impedance for this IC is provided by the FET biased input stage and this also makes this IC suitable for audio applications. A switch S1 is used in this circuit to accomplish circuit ON/OFF. An indicator LED shows whether the circuit is powered or not. Resistor R2 (100K) and capacitor C1 (0.1 uF) connected to the non-inverting terminal (pin 3) of OPA 134 is a high-pass filter network having a corner frequency approximately 15 KHz. To reduce noise and distortion in output, a load resistance R5 (20 ohm) is used. This load resistance also stabilizes the virtual ground. The output of this circuit is DC coupled. The variable resistor port R1 (47K) is the volume controller of this amplifier circuit.

Split power supply of +/- 4.5 V is required for IC OPA 134. This obtained from a 9V PP3 battery using a network composed of resistors R6 (10K), R7 (4.7K), R8 (4.7K) and capacitors C2 (220 uF), C3 (220 uF).

Circuit Diagram

Simple Pocket Headphone Amplifier Circuit

Simple Pocket Headphone Amplifier Circuit

Notes

  • Use a good quality PCB to assemble components.
  • Sound sources like MP3 players, I Pods, mobile phones etc can be plugged in this circuit.
  • IC OPA 134 is specially designed for audio applications.
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