Four-channel PWM power amplifier circuit board

This PWM power amplifier board is used for PLC drive signal enhancement. It employs multi-channel optocoupler isolation and single-channel NMOS field-effect transistor (FET) drive.
The selected optocouplers are from the PC817 series, and the NMOS model chosen is LR7843.
The PC817 optocoupler consists of a GaAs emitter and an NPN transistor.
     The optocoupler comprises an LED emitter and a photosensitive element receiver.
When the LED emits light and the light shines on the photosensitive sensor, the photosensitive sensor begins to flow current. In this system, the input light is proportional to the output current. The LR7843
   FET
 
is a high-performance NMOS transistor, typically capable of handling maximum currents of 100A to 120A.
Furthermore, it has low on-resistance, helping to reduce energy loss during conduction and improve overall efficiency.
Its source-drain voltage (Vds) can reach 30V, allowing the LR7843 to operate stably at higher voltages.
  In the PWM amplifier driver circuit, electrical isolation is achieved through an optocoupler, and the PWM signal is amplified using an NMOS transistor.
The conduction level of the NMOS transistor is controlled by adjusting the magnitude of the PWM signal at the OUT terminal, thus realizing the function of amplifying the PWM signal. Its circuit diagram is shown below:
            PWM Power Amplifier Circuit