Use LC901 to make high-end bedside lamp controller

LC901 has three wind speed output terminals: strong wind S, medium wind M, and weak wind L. They are controlled by the wind speed selection terminal ss. Every time the ss
terminal receives a negative pulse trigger , the S, M, and L terminals appear low in sequence, triggering the thyristors vsl, VS2, and
VS3 to conduct in sequence. VS4 and its peripheral components form a bidirectional thyristor dimming circuit. If vsl is turned on, the positive power supply
charges the phase-shifting capacitor C9 through VSI and RPI, and the C9 voltage is added to the bidirectional trigger diode VD3 through R7. If the C9 voltage is greater than
the breakdown of VD3 voltage, the thyristor VS4 is turned on, and the lamp H is energized and emits light. We only need to adjust the potentiometer RP1 to change
the conduction angle of the thyristor VS. Usually, we can adjust RPI to make the lamp H emit weak light. If the thyristor VS2 is turned on, the power supply
charges the phase-shifting capacitor C9 through VS2 and RP2, and the lamp H can be made to emit medium light by adjusting the potentiometer RP2. If VS3 is turned on, the power supply
charges C9 through VS3 and RP3. Adjusting the potentiometer RP3 can make the lamp H shine brightly. The button S2 connected to the wind speed selection terminal ss
is the light brightness selection switch. Pressing S2 inputs a negative pulse to the ss terminal, so that the output terminals S, M, and L
output the trigger level and trigger the thyristors VS1~VS3. Therefore, the light brightness can be switched between low light, medium light and strong light.
In the shutdown state, this button can also be used as the power-on button. When the power is turned on for the first time, it is in a low-light state, that is, the L end of pin l3 outputs low level, and
VS1 is turned on. Because RP1 has the largest resistance value among the three potentiometers, the light H emits weak light.
    The 5th pin OFF of the integrated block is the shutdown key input terminal. Press the switch sl to input a negative pulse to the OFF terminal.
The integrated circuit is in the reset state. There is no level output at the S, M, and L terminals, and VS1~VS3 are all turned off. , the light H goes out. Pin 14 T is the input terminal of the
timing key. When the switch S3 is turned on, a negative pulse is input to the T terminal. Different timing times can be selected. The selection method is: irregular -
0.5h - th ~ 2h - 4h - irregular -..., cycle choose. In the timing state,
a corresponding light-emitting diode among the timing indicators LEDI~LED4 lights up. If the light-emitting diode connected in series to pin 8 lights up, it means 2h timing.
All light-emitting tubes are off, indicating irregular timing . The 15-pin MS terminal is the wind selection terminal. This circuit does not need to be
grounded through capacitor C7.
    VDI, VD2, C1~C3 form a simple capacitor step-down half-wave rectification and voltage stabilizing circuit, which outputs about 6V DC voltage for
the integrated block LC901.