20W Bridge Audio Amplifier Wiring diagram Schematic

Specifications:

• 20W Bridge Audio Amplifier kit, based on the TDA2005 IC, a class B dual audio amplifier, specifically designed for car radio applications etc.
• Power supply - 18 VDC
• Output power - 20 W, 4 Ω
• IC built in Thermal Shut-down, Load dump voltage surge protected
• Terminal pins for connecting left and right audio signal inputs
• Relimate Connector for connecting Potentiometer (POT) for volume adjustment
• Power Battery Terminal (PBT) for easy power supply and speaker connection
• Power-On LED indicator
• Heatsink for IC
• Four mounting holes of 3.2 mm each with nut and stud
• PCB dimensions 63 mm x 65 mm

20W Bridge Audio Amplifier Circuit Diagram

Pcb

Parts List

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Wheatstone bridge

A Wheatstone bridge is an electrical schema used to
measure an unknown electrical resistance by balancing two
legs of a bridge schema, one leg of which includes the
unknown component. Its operation is similar to the original
potentiometer. It was invented by Samuel Hunter Christie in
1833 and improved and popularized by Sir Charles
Wheatstone in 1843. One of the Wheatstone bridges initial
uses was for the purpose of soils analysis and
comparison.

Operation

In the figure, is the unknown resistance to be measured; , and are resistors of known resistance and

the resistance of is adjustable. If the ratio of the two resistances in the known leg is equal to the ratio of

the two in the unknown leg , then the voltage between the two midpoints (B and D) will be zero and no

current will flow through the galvanometer . If the bridge is unbalanced, the direction of the current indicates

whether is too high or too low. is varied until there is no current through the galvanometer, which then reads

zero.

Detecting zero current with a galvanometer can be done to extremely high accuracy. Therefore, if , and

are known to high precision, then can be measured to high precision. Very small changes in disrupt the

balance and are readily detected.

At the point of balance, the ratio of

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Simple Bridge Rectifier Wiring diagram Schematic

This Simple Bridge Rectifier Circuit Diagram is intended for those cases where two unequal supply voltages are required. The lower voltage is obtained with the aid of a transformer with symmetric windings and half-wave rectification of the potential across one winding. For the higher voltage, the potential across both windings is rectified. To that end, the output of the transformer is linked to the bridge rectifier via two electrolytic capacitors that provide isolation of the two direct voltages. 

 Simple Bridge Rectifier Circuit Diagram

A bonus with this type of schema is that although the two supplies can be loaded unequally, the currents through the two transformer windings are the same. Thus, the transformer is loaded symmetrically so that its full capacity can be used. Moreover, no unnecessary dissipation is in the voltage regulators. The load on the lower voltage supply depends primarily on the rating of the transformer. The load on the higher voltage supply is limited by the reactance of Cj and C2 (= xh r 50 C) and the required minimum output voltage.

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