12 W Bridge Amplifier circuit diagram

The following schematic shows 12 W Bridge Amplifier circuit diagram as an application of the TDA2007A a class AB dual audio power amplifier which is designed for stereo application in music centers, TV receivers and portable radios. According to the datasheet, this TDA2007A has features such high output power, high current capability, AC short circuit protection, and thermal overload. via next.gr

12 W Bridge Amplifier circuit diagram

The Stereo Power Meter

The Stereo Power Meter is made up of two identical circuits and a power supply. Each circuit contains Jwo LM3914 display chips which contain 10 voltage comparators, a 10-step voltage divider, a referencevoltage source, and a mode-select circuit that selects a bar or dot display via a logic input at pin 9. The brightness of the LEDs is controlled by the 1900-!l resistors and the reference voltage is controlled by the 3900-!l resistors. The 10-step voltage divider within the chips is connected between the reference voltage and ground. Since each step of the voltage divider is separated by a 1-K!l resistor, each comparator senses a voltage 1 O% greater than the preceding comparator. The signal is applied to pin 5, which is buffered through a resistor-diode network and then amplified as it passes to each of the 10 comparators. Each LED is grounded through the comparators as the input signal voltage matches the reference voltage. That results in one to 10 LEDs illuminating as the signal voltage increases.

The Stereo Power Meter

Mono audio panoramic interference

The circuit spectator interference enables implantation mono sound at any point between stereo speakers. When P1 is in the middle of his journey, there is strengthening or weakening of the mark the entrance to the exit in any of the two channels. When the potentiometer placed elsewhere, away from halfway, the signal in one channel is supported 3dB more than the other. The input stage is a buffer (IC1). Inverts the input signal to ensure compliance with this phase of the output (Next steps' and reverse them the signal they receive to entry). The resistance value entry identifies to that of R 1 (1 A KO). The output buffer is driven in stereo amplifiers IC2 and IC3.

The potentiometer P1, in conjunction with the A3, R4, R8, and A9, affects the routes of feedback and two boosters. This result in any adjustment of P1 to make the opposite metavoles enischysi the two opamps. The series resistors A7 and A12 provide the possibility of output lead capacitive loads. Capacitors coupling C3, C6 and C9 can be omitted if the application for the intended circuit can tolerate continuous diversion trends in output of about 20-30 mv. The capacitors C2, C5 and C8 ensure stability amplifier, even with unit gain. The capacitors C 1, C4 and C7 minimize any interference r1, which is probably appears within the area 2.5IZ-200KIZ. The performance of the circuit is very good and can be used in High-quality consoles. The total harmonic distortion plus thorythoo the frequency of 1 kHz with a bandwidth of 22 kHz is 0.0014%. The circuit needs power supply 18 W of power which consumes approximately 16 mA.

 Mono audio panoramic interference

Stereo Tv Decoder Circuit

Ql is an audio amplifier and Ul is used as a 31.5-kHz subcarrier, which is similar to 38-kHz FM MPX. Pilot frequency is 15.734 kHz. 

Stereo Tv Decoder Circuit

FM tuners, the stereo indicator lights upon detection

On most FM tuners, the stereo indicator lights upon detection of the 19-kHz pilot tone. However, this doesn`t mean that the program is actually stereophonic, since the pilot tone is often transmitted with mono programs also. A similar situation exists on stereo amplifiers, where the stereo LED is simply controlled from the mono/stereo switch. The LED-based stereo indicator described here lights only when a true stereo signal is fed to the inputs. Differential amplifier Al raises the difference between the L and R input signals. When these are equal, the output of Al remains at the same potential as the output of A2, which forms a virtual ground rail at half the supply voltage. When Al detects a difference between the L and Rinput signals, it supplies a positive or negative voltage with respect to the virtual ground rail, and so causes C3 to be charged via Dl or C4 via D2. Comparator A3/A4 switches on the LED driver via OR circuit D3/D4. The input signal level should not be less than 100 mV to compensate for the drop across Dl or D2. The sensitivity of the stereo indicator is adjustable with Pl.

FM tuners, the stereo indicator lights upon detection

LM378 dual4-watt amplifier Mini-stereo

This circuit is built around two chips: the MC1458 dual op amp, configured as a preamplifier, and the LM378 dual4-watt amplifier. The gain of the preamp is given by R3/R1 for one side and R4/R2 for the other side, which is about 100. That gain can be varied by increasing the ratios. The left and right channel inputs are applied to pins 2 and 6. The left and right outputs of U1 at pins 7 and 2 are coupled through CS/ RlO and C3/R6, respectively, to U2 to drive the two 8-0loudspeakers.

LM378 dual4-watt amplifier Mini-stereo

Derived Center-Channel Stereo System

A simple method of deriving a center or third channel without the use of an extra transformer or amplifier, (a) 4- speakers are connected to 8- amplifier taps. 8 and 16- speakers connect to 16- taps, (b) By blending the inputs it is possible to cancel out undesired crosstalk.

Derived Center-Channel Stereo System