Power amplifier electronic circuits-tube audio rf amplifiers

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

January 12th, 2011

Hi-fi Amplifier Circuit

Circuit Description

Figure gives the circuit diagram of 2X12 W Hi-Fi Amplifier. This amplifier circuit is based on TDA 2616 IC which is the core part of this circuit. The TDA2616 is a stereo power amplifier IC. It is a 9-lead single-in-line (SIL9) plastic power package (SOT131). This amplifier IC finds applications in mains fed amplifier circuits such as stereo radio, tape and television. It has gain balance for both of the channels and hi-fi according to standards such as IEC 268 and DIN 45500. This IC has special inbuilt circuit for the suppression of noise signals at the inputs, during switch-on and switch-off. This avoids click sounds during power on and power off.

Simple and less number of components make this circuit suitable for portable power amplifier circuits. A well regulated and filtered +/- 12 V dual power supply is used in this circuit to provide at least 2 A continuous current. The circuit can deliver a maximum output of 12 W power on 8 Ohm speaker for each channel at +/- 12 V dual supplies. This Hi-fi amplifier circuit can complement your audio system with ceiling speakers for home theater.

Circuit Diagram

Hi-Fi Amplifier Circuit

Hi-Fi Amplifier Circuit

Notes

  • Use a good quality PCB to assemble this particular circuit.
  • IC TDA 2616 is from Philips.
  • All capacitors except C10 & C9 are ceramic type.
June 11th, 2010

555 Timer Police Siren Circuit

Circuit Description

Police siren circuit given here is a circuit based on NE 555 timer IC. This circuit uses two NE 555 ICs (IC1 and IC2) and which are the core working parts of this circuit. Here two timer ICs are wired to work as astable multivibrators. But these two timer ICs are working at different frequencies. IC1 is slow astable multivibrator operating at a frequency of 20Hz and a duty cycle of 50% whereas IC2 works at 600Hz as fast astable multivibrator. The output of IC1 is fed to the control pin (pin5) of IC2. By this connection, the output frequency of IC2 will be modulated with the output frequency of IC1.

The circuit can be powered from a DC supply voltage ranging between 6V and 15V. Power supply used here is 12V DC supply. The loudness of output can be further increased by inserting a power amplifier circuit at the output stage of this circuit.

Circuit Diagram

555 Timer Police Siren Circuit

555 Timer Police Siren Circuit

Notes

  • Use a Perf board to assemble this circuit.
  • The output frequency of IC2 is controlled by the output of IC1.
  • One NE 556 IC can be used instead of two NE 555 ICs.

Use speaker with rating 64 ohm, 500mW.

June 10th, 2010

Voltage Doubler Circuit

Circuit Description

The circuit diagram given here is a simple voltage doubler circuit. In this circuit the central part is the timer IC NE 555. This circuit also includes two transistors Q1 (BC 107) and Q2 (BC 177) as its main part. The actual output current delivered by this circuit is 50 mA and it is suitable only for low current applications. The output voltage of this circuit will be approximately 19V for 12V DC input voltage.

In this circuit, the IC1 NE 555 acts as astable multivibrator operates at a frequency of 9 KHz. The output of this astable multivibrator is connected to the base of the transistors Q1 and Q2. The capacitor C3 is connected in such a way that its negative terminal is shorted to the output of two transistors. When the output of the astable multivibrator becomes low, Q1 will be off and Q2 will be on and capacitor charges. When the output of astable multivibrator goes high, reverse will happen and capacitor again charges to the double of the supply voltage. So the final output across capacitor C4 will be the double of the input voltage.

Circuit Diagram

Voltage Doubler Circuit

Voltage Doubler Circuit

Notes

  • Use a Vero board to assemble this circuit.
  • Use a holder to mount IC1.