Wiring circuit

A portion of electronic circuits into the domain of audio amplifiers are already been available at this juncture. This circuit is a hardly singular for the reason that it is a four channel amplifier. each one channel of this amplifier can furnish with an output of 15Watts into a 4 ohm amplifier. The amplifier can subsist operated from a single 12V DC supply and this makes it likely to spend this amplifier happening car audio applications too.

The circuit is based on the 15W BTL X 2 channel audio power amplifier IC TA8215 from Toshiba. Even though whittle is specifically designed designed for car audio applications it can stay and used for to your place audio applications. Two TA8215 ICs are used now in order to gain a 4 channel amplifier practice. The circuit is designed almost exactly in the role of for each the use diagram within the ICs datasheet. Pins 7 and 19 are the Vcc pins of the ICs inner integrated power amplifier stages and these pins are connected to the optimistic supply. Pin 9 is the Vcc pin in lieu of ICs interior preamplifier and it is additionally connected to the positive supply. 

Pins 13 and 14 are the domestic power amplifiers ground pins and they are fixed cool and connected to the ground. The in-house preamplifier’s ground pin (pin5) is connected to the regular ground through a 10 Ohm resistor which makes the input ground separated from the common ground by a resistance of 10 ohms and this improves the sound rejection. The 100uF capacitor workings in the function of a power supply de-coupler. The resistor networks connected to the output defenses of both amplifier improves the far above the ground frequency stability. The movable resistors (R3, R4, R12 and R13) facility as the volume controller intended for the corresponding channels.

This circuit is of interest not merely because it uses a bell transformer with a single secondary winding to provide symmetrical voltages for low current applications but also because the final output voltages are greater than the normal bell transformer (220 V/8 V) output. In fact the final output can be as much as twice this value.
This multiplication is achieved using two voltage doublers each consisting of two diodes and two capacitors, connected head to tail. Each diode/capacitor couple takes every alternate half cycle of the sinusoidal voltage such that the output voltage U is (theoretically) equal to 2/2 U8ff_, where Uefg is the effective output voltage of the transformer. A current of 150 . . .200 mA and 1 V of ripple can be expected using the capacitor values shown here. In order to increase this current without a similar increase in ripple the values of the capacitors may be made greater but C1 must be approximately the same as C2, and C3 about the same as C4. To get a stable symmetrical output of i 15 V two voltage regulators, a 7815 and a 7915, should be used. This will then allow a bell transformer to be used for any small circuits with operational amplifiers requiring a symmetrical supply of 14 or 15 V and a current of 0.1 .. .0.2 A.