Power amplifier electronic circuits-tube audio rf amplifiers

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

August 21st, 2009

Low Power Single Tracer Circuit

About The Circuit
Given below is the woking as well as circuit diagram of a single tracer sircuit made with the use of uA 741 operational-amplifier. The main advantage of such a circuit is that with a battery of 6 to 9 Volts a high gain amplifier can be easily obtained. For this, all we have to do is to set IC1 as a high gain non-inverting amplifier. Inorder to drive the speaker a pair of complementary transistors are used named as Q1 and Q2. The two transistors Q1 and Q2 stabilizes the overall gain of the amplifier due to the negative feedback from common emitter junction.

The circuit has to be made neatly in a printed circuit board. We must also note down that the capacitors have a minimum rating of 15 Volts. The IC uA 741 should be mounted on an IC base. For adjusting the volume level POT R6 can be used.

Circuit Schematic

 low-power-single-tracer-circuit.JPG

 

 

 

August 21st, 2009

Simple Amplifier circuit for Headphones

About The Circuit

Though the headphones that are present in the market today are good enough, the music player may not be able to provide enough power to drive the headphone. The only way to make them produce a clear and gud sound is to amplify them. For this, a very simple circuit is enough consisting of three amplifiers. The circuit only needs a 3 Volts battery and needs to be made on a good quality Printed Circuit Board.
The transistors used for this circuit are BC 239 BC 337 and BC 327. Out of these Q1 (BC 239) acts as the pre-amplifier, while transistors Q2 (BC 337) and Q3 (BC 327) act as the driver circuit for the speaker. The performance of the circuit is increased by feeding back the emitter voltage of Q1 the base of Q1 itself through the resistance R3. You must also note down that the capacitors have a rating of 10 Volts. After the circuit is made all you have to do is ON/OFF the switch S1.

 

Circuit Schematic

 

amplifier-circuit-for-headphone.JPG

August 21st, 2009

Guitar Pre-amplifier Circuit

About The Circuit

Here is a simple guitar pre-amplifier circuit. The circuit is designed for high oimpedance type electric guitar pickups. An op-amp IC uA 741 is all that is required. uA 741 IC is IC1 which acts as the non-inverting amplifier. The volume can be controlled with the help of POT R1 and the tone can be controlled with the help of POT R6. The tone effects can be adjusted to “SOFT” and “BRILLIANT” modes with the help of switch S1.

An input voltage of 12 Volt DC power supply or battery is more than enough, though a maximum of 24 Volts can be used.

Circuit Schematic

 

guitar-preamplifier-ua-7141.JPG