The diagram is as follows
Detailed analysis:
1. Assuming there is no resistor R1, when the chip breaks down, the VCC pin inside the chip is short-circuited to GND. Since the VCC pin is directly connected to the 15V power supply, the 15V will be pulled directly to ground, causing damage to the power supply.
2. Connect resistor R1. When the chip is damaged, the 15V voltage will not be directly pulled to ground. Therefore, the function of this resistor is to prevent a short circuit in the power supply after the chip is damaged, thus protecting the power supply.
3. When the 15V voltage suddenly fluctuates significantly, generating a large pulse voltage, the presence of resistor R1 can act as a voltage divider, reducing the voltage input to the chip and protecting it.
Note: Resistor R1 is connected in series between the 15V and the chip, which will generate a certain voltage drop. Therefore, this resistor should not be too large, and its value is generally in the tens of ohms.
