HT7713 dimming control ASIC

The typical application circuit of HT7713 is shown in Figure 2-12. In the figure, VDI, Rl, VD2 and C2 form a simple resistor
step-down half-wave rectifier and voltage stabilizing circuit, which outputs about 10V DC voltage for the integrated block. The AC synchronization signal is fed by resistor R2.
M is a touch electrode piece. When a human hand touches M, a control signal is input to the integrated block, and pin 3 outputs a trigger signal
to control the conduction angle of the thyristor vs. When M is touched for the first time, the lamp H emits weak light; when M is touched for the second time, the lamp emits medium light
; when M is touched for the third time, the lamp emits strong light; when M is touched for the fourth time, the lamp goes out; when M is touched for the fifth time, the lamp H emits weak light again. Light... follows this cycle
to select the brightness of the electric lamp. C4 is an isolation safety capacitor to protect users from electric shock. VD3 and VD4 are
protection diodes, which can prevent damage to the integrated block due to accidental input of excessive touch signals.