Automotive integrated circuit regulator circuit

The integrated circuit regulator is suitable for 14V, 350-d500W externally grounded silicon rectifier generators (such as JF2132N, JF2132A, JF213E
generators used on Dongfeng E0109a cars ). The internal circuit of this regulator is shown in the figure. The working principle of the regulating circuit is as follows:
    1) After turning on the ignition switch S, the battery voltage is added to the voltage divider composed of resistors Ri, R3. At this time, the potential of point A is lower than
the reverse breakdown voltage of the voltage regulator tube VDS. Therefore, VS3 does not conduct, and transistor VT1 has no base current and is in a cut-off state. The battery
provides base current to VT2 through R5, causing VT2 and VS3 to conduct. The current starts from the "+" pole of the battery, passes through the ignition switch S, the magnetic field
winding, VS3 (c and e poles), the ground, and returns to the "one" pole of the battery, forming a loop. The generator has a magnetic field current and starts to generate electricity and as the speed increases
, the voltage also increases accordingly.
    2) When the generator voltage exceeds the specified value (14±0.2)V and the voltage at point A is higher than the reverse breakdown voltage of the voltage regulator tube VS3, VS3 is turned on
and VT1 is turned on. When VT1 is turned on, its collector voltage decreases, causing VT2 and VT3 to cut off, cutting off the generator magnetic field circuit and causing the generator
output voltage to drop.
    3) When the generator voltage is lower than the specified value, the VS3 fork is cut off. VT1 is cut off, so VT2 and VT3 are turned on, the excitation current is turned on again, and
the generator voltage rises again. Repeat this process until the generator voltage stabilizes within the specified value range.