Molding machine control circuit

Circuit working principle: As can be seen from the figure, LED indicates the action of power supply and air pressure sensor
. After the vacuum cleaner works for a long time, the internal dust bag is not cleaned in time, which will
increase the motor load. At this time, if the internal vacuum pressure reaches or exceeds 21 kPa, the air pressure
sensor will act. Once the air pressure detection end of the microcontroller detects the air pressure sensor action, then No
matter what power state the motor is working in, it will quickly return to the low power state.
The light-emitting diode LED and LED 2 will flash
cyclically to remind the user to clean up dust, thus effectively Ground protects the motor . The 220 V alternating
current is divided into two channels after being stepped down by the transformer T. One channel is connected to the RAz terminal of the microcontroller through R8 and C6 for AC zero-crossing sampling, so that the thyristor
controlled by the microcontroller can be completely synchronized with the AC mains, using thyristor phase shifting. Trigger mode, high and low voltage are isolated through photoelectric coupler , which improves safety; the other path is through diode VD. Connect to 78L05 to stabilize the voltage and then power the microcontroller.