Figure shows the superior performance of the power amplifier circuit. It has small size, power, high efficiency.
How it works: AC power input is filtered by the T1 and divided into two outputs, all the way to step-down transformer T3, the primary circuit in the T3 series were two-way thyristor KS, used to change the primary AC power transformer T3. Another way through a capacitor C1 after the rectifier buck by VD1 to trigger control circuit after the voltage regulator to provide DC voltage. R3, C3, VQ3 and transformer T2 form a relaxation oscillator circuit. R2, R4 and VQ1, VQ2 composition of the current source, constant current charging the capacitor C3. When the voltage across C3 is sufficient to VQ3 breakdown voltage, C3 through VQ3 the emitter, base and the transformer T2 primary coil discharge, the secondary of transformer T2 are trigger pulse thyristor KS, control thyristor KS conduction tube so that the work of the transformer T3. T3 of the transformer secondary, the rectification, filtering required by power amplifier positive and negative DC voltage symmetry. The voltage across the discharge capacitor C3 to VQ3 the valley point voltage, VQ3 the emitter and the base is closed, and prepare for the next cycle of charging and discharging capacitor C3. R6 ~ R9, VQ4, VD2 compared with W1 amplifier circuit composed of voltage and adjust the output voltage can be changed W1, and by IC1 to control VQ1, VQ2 current source of the current changes in C3 to charge and discharge time, the derivative control thyristor VKS on angle, thus changing the primary AC power transformer T3, be constant in the secondary output voltage to ensure that the instantaneous power amplifier.
Select components: transformer T2 with a 5mm × 5mm of the E-type core self, the primary voice F0.15mm the enameled wire can be used around the 200 laps, 135 laps around the secondary. 40mm × 60mm T3 transformer iron core can be wound, the primary winding of enameled wire with F0.9mm 352 laps, the secondary winding of enameled wire with sound F1.26mm 176 laps, 88 laps at the tap. Other components as shown.
