simple PA system

93 simpte PA system A very nice power amplifier deliver- ing 10 W into 2 Sl (two 4 S2 loud- speakers in parallel) can be built using the TDA 2003 IC and a few passive components. The RC network of R3/C5 acts as a component of the output load and compensates for the rising impedance of the loudspeaker at high frequency. The power supply is connected to pins 3 and 5 and maximum supply voltage is 18 V. Higher supply volt- ages will not necessarily damage the IC but will mean that the output d.c. voltage drops to such a level that the IC can no longer be driven. The IC also includes short-circuit, over- bad and thermal protection. To maintain stability it is rec- commended that separate wires are used to connect the 0 V of the printed circuit board and the loud- speaker independently to the main earthing point on the chassis. After construction is completed the current consumption of the circuit should be checked. It should be about 50 mA, and the value of the d.c. voltage at the outp...