Microwave radar detection automatic light circuit (4)

It is an induction automatic light made by using the novel microwave transmitting and receiving module TWII9250A .
When the blind person is meters away, the light will turn on; after the person leaves, the light will turn on.
    The 210V alternating current is stepped down by the voltage monitor
T, rectified by VD1
, stabilized by the terminal voltage stabilizing integrated block
Al, and
a stable DC voltage of 12V is output for use by the micro-duration module
Al.
The Y and Y-terminal loop antennas connected to Al not only
emit microwave signals outwards, but also
receive the waves reflected back from the objects
. When someone moves,
A] will receive the concave wave signal
and the phase will change, 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 O terminal of the module outputs a low level, and the relay K suction table, its moving contact kl l0 is closed, the electric lamp E lights up
and glows r after the person leaves the well, the circuit can delay dos, then the relay K is released, and the lamp goes out. If people keep asking H
to move, then the lamp E can stay on K. The lj potentiometer RP can adjust the detection sensitivity of the circuit. RL constitutes
a light control circuit. During the day or when the indoor light is strong, RI. Because of the low resistance, the circuit will be blocked and will not work
. The circuit can only work normally at night or when the light is dark.
    The overall dimensions and pin locations of the TWH9250 microwave module are shown in Figure 187(b). The loop antenna is made of ≠l-
≠3mm enameled wire bent into a ≠80mm ring shape, and then connected to the Y and Y ends of the module. During debugging, make
the axial direction of the loop antenna consistent with the direction of pedestrians (the sensitivity is highest at this time), and then turn on the power. You will find that the K market is attracted and
maintained for 40 seconds. This is the first pre-stable state when power is turned on. After this state ends, K will act twice continuously
, and then the circuit will enter the normal working state. If the sensitivity does not meet the requirements, you can add RP until it is satisfactory.