Infrared control dimming circuit

The receiving circuit is as shown in the figure. When the infrared receiving tube receives the remote control signal from the transmitter, it is processed by KA2184 and outputs
a low level from the pin. This low level is directly added to the base of VT to turn it on, and the current output by its collector forms a high level output at the upper end of R4
. This high level is added to the auxiliary input terminal (⑥ pin) of the LS7232 dimming circuit through R6. As a control signal for dimming.
    This is an infrared remote control dimming circuit . When its ⑥ pin inputs a trigger signal, its ⑧ pin will continuously output
control pulses to control the conduction pin of the bidirectional thyristor, so that the conduction angle of the bidirectional thyristor is between 410 and 160. changes between. As the conduction angle of the bidirectional thyristor changes, the light also changes from
dark to bright or from bright to dark, thereby realizing dimming control of the light.
    During the dimming process, when you need the light to change from dark to bright, you can press and hold the transmit button on the remote control to continuously send control signals. At this time, you can see that
the light is gradually getting brighter. When the required brightness is reached, release the emission button immediately, and the brightness of the light will stay at this position. If
you press it continuously, the light fork will gradually dim from bright to dark until it goes out.
    It should be noted that: LS7232 is a PMOS type integrated circuit, so its power supply polarity is opposite to that of commonly used CMOS circuits, that is,
its n. The power terminal should be connected to the negative pole of the power supply, and the Vss terminal should be connected to the positive pole of the power supply.
    The power supply of this circuit still uses AC power supply, capacitor C7 step-down, and diode VDI half-wave rectification. Different from other capacitor step-down power supply circuits
, the step-down capacitor C7 of this power supply is connected in parallel with a 220yH inductor, which is used to absorb I. The harmonics generated by S7232 prevent
it from interfering with other electrical appliances through the power line.