TC924P DC machine PLL system

Use LM324 four operational amplifiers, two of which are connected to pins 7 and 8 as followers,
each connected to 22kfl to the hybrid correction amplifier, and the resistor-capacitor network plays a correction role. Since
the power supply is 8v, the non-phase auxiliary terminal of the amplifier is connected to the voltage regulator tube ZD to generate 4.2V, so that
the phase difference is maintained near "" during phase locking. The final stage uses NE555 to generate a delta transition to realize PWM
modulation power switching. When the system is running, if When the speed is lower than the set value and FGw is low, AFC
outputs high level
, which increases the pulse width and accelerates the motor; conversely, if the speed is higher than the set value and FGr is above the locking range, AFC is low level , causing the motor to accelerate. The motor decelerates.
After the frequency identification enters the locking range, AFC changes around .%. At this time, it is adjusted by APC to make
the phase difference swing around n. At this time, the frequency difference is zero, achieving high-precision and stable speed.