Project Expo.: April 2013

100watt sub woofer amplifier circuit

Description

This is the circuit diagram of fully transistorized sub woofer amplifier that can produce an output of

100w .There are seven transistors including four in the output stage. Transistors Q1 and Q2 form the

pre-amplifier stage. Transistors Q4 and Q7 from the output stage.Since no ICs are used the circuit is very

robust and can be easily assembled on a general purpose PCB.

Notes

The circuit can be powered from +35v /-35, 5A dual power supply.
Use 100W ,12 inch sub woofer at output.
All electrolytic capacitors must be rated 100V.
Transistors Q4 and Q7 must be fitted with heat sinks.

Tester For Remote Control

Here is a simple tester for checking the basic operations of an infrared remote control unit. It is low-cost and easy to construct. The tester is built around infrared receiver module TSOP1738. Operation of the remote control is acknowledged by a tone from the buzzer. The circuit is sensitive and has a range of approximately five meters The integrated IR receiver detects, amplifies and demodulates IR signals from the remote control unit. The piezobuzzer connected at its output sounds to indicate the presence of signal from the remote control unit. As shown in Fig. 1, output pin 3 of IR receiver module TSOP1738 (IRX1) normally remains high and the piezobuzzer is in silent mode. When the IR module I R X 1 receives an i n f r a r e d signal, its

output goes low and, as a result, the piezobuzzer sounds to indicate the reception of signal from the remote (such as TV remote control unit). P o w e r supply for the circuit is derived from the mains using a capacitive potential dropper, a half-wave rectifier, a shunt regulator and associated components. Make sure that capacitor C1 is of X2 type. Use a suitably small enclosure to make the unit handy. Assemble the circuit on a general purpose PCB and enclose in a cabinet. Make sure that the IR receiver module is placed on the front panel of the cabinet so that it can receive the IR signals easily. Before soldering/connecting the shunt regulator and IR module, refer

Fig. 2 for the pin configuration.

Low power amplifier circuit using lm386

C - 250uF, 16V

12 watt stereo amplifier using LA4440

Built-in 2 channels (dual) enabling use in stereo and bridge
amplifier applications
Dual : 6W´2 (typ.)
Bridge : 19W (typ.)
Minimum number of external parts required.
Small pop noise at the time of power supply ON/OFF and
good starting balance.
Good ripple rejection : 46dB (typ.)
Good channel separation.
Small residual noise (Rg=0).
Low distortion over a wide range from low frequencies to
high frequencies.
Easy to design radiator fin.
Built-in audio muting function.
Built-in protectors

a. Thermal protecton

b. Over voltage, surge voltage protecto

c. Pin-to-pin short protector

100 Watt audio amplifier using TDA7294

DMOS power stage
very high operating voltage range
high output power (up to 100W music power)
muting/stand-by functions
no switch on/off noise
no boucherot cells
very low distortion
very low noise
short circuit protection
thermal shutdown

14Watt Amplifier using TDA2030

The TDA2030 is a monolithic integrated circuit in Pentawatt® package, intended for use as a low

frequency class AB amplifier. Typically it provides 14W output power (d = 0.5%) at 14V/4W; at ± 14V

or 28V, the guaranteed output power is 12W on a 4W load and 8W on a 8W (DIN45500). The TDA2030 provides high output current and has very low harmonic and cross-over distortion. Further the device incorporates an original (and patented) short circuit protection system comprising an arrangement for automatically limiting the dissipated power so as to keep the working point of the output transistors within their safe operating area. A conventional thermal shut-down system is also included.