Make automatic lighting with TWH9250

The automatic lighting circuit made with TWH9250 is shown in Figure 3-72. The circuit consists of a microwave module, a voltage stabilizing integrated block and a small
number of other components.
    The 220V AC power is stepped down by transformer T, rectified by VD1, and stabilized by the three-terminal voltage stabilizing integrated block A2 , and outputs a stable
DC voltage of 12V for use by microwave module A1. The loop antenna connected to the Y and Y ends of Al not only emits microwave signals outward, but also
receives the echo reflected from the object. When someone moves , Al receives the echo signal and the phase changes, generating a
low-frequency signal that moves with the human body. After being compared and amplified by the internal circuit, the switch circuit is triggered, so that the 0 terminal of the module outputs
a low level } and the relay K is When the electric suction device is used, its normally open contact kl is closed, and the electric lamp H lights up. After the person leaves, the circuit can delay
for 40 seconds, then relay K is released and the light goes out. If people keep moving back and forth , the light H can stay on. Adjusting
the potentiometer RP can adjust the detection sensitivity of the circuit.
    RG constitutes a light control circuit. During the day or when the indoor light is strong, RG has a low resistance and the circuit will be blocked and will not work.
The circuit can only work normally at night or when the light is dark.