Power amplifier electronic circuits-tube audio rf amplifiers

About The Circuit

Here is the circuit diagram of a 2X15 Watts stereo amplifier, which is also reffered to as a 30 Watt mono BTL amplifier. The IC called TDA 4935 is used here. This bipolar stereo amplifier has a built in circuitory for protection from overload as well as overtempreature shut down. The main features of this circuit is that there is no need of a dual power supply and it has a power voltage varying from (8-24)Volts.

The K1 and K2 speakers should have a rating of 20 Watts, 4 Ohms. The electrolytic capacitors should have a minimum rating of atleast 25 Volts.

Circuit Schematic

About The Circuit

Given below is the working as well as circuit schematic of  24 Watts mono-amplifier using IC TDA 1516. It is a 13 pin SIL package with an integrated class B power amplifier. The IC has to be connected in BTL mode so as to provide 24 Watts of power for a 4 Ohm speaker. This amplifier only needs a 12 Volts DC power supply  and so is appropriate to be used as car stereos. The IC must be given special care and so must be fitted into a heat sink.

The circuit will be best working when assembled in a high quality PCB. It must be noted that the capacitor must have a minimum rating of 25 Volts. Also note that the Switch S1 is used as the stand by switch.
Take a look at the circuit diagram and do bring in your comments.

Circuit Schematic

About The Circuit

Here is a simple circuit of an audio amplifier which can deliver almost 12 Watts to an 8 Ohm speaker. For the working an Op-amp IC called TL 081 is used. It is actually used as a pre-amplifier which can be switched with any other Op-amp which has almost equal power ratings. TIP 125 is used as Q1 and TIP 120 is used as Q2. Both of them are used in the power amplifier stage. These transistors should be used only along with heat sinks. It is also suggested to better mount IC TL 081 on a holder. The power for the circuit can be provided with the help of a +15V/-15V dual power supply.

This circuit can be easily assembled on a Vero board. The output is taken off the collector junction of the transistors Q1 and Q2.

Circuit Schematic