The power supply overvoltage protection circuit is as shown:
Figure (a) is a simple and practical overvoltage protection circuit. It uses the Zener diode Dz to limit the power supply voltage of the integrated operational amplifier to a safe voltage range. The selection method of the operating voltage of the Zener diode can be based on the following formula: Vz≤2Vsmax . Generally, Vz should be as close as possible to or equal to the total voltage of the power supply. The current limiting resistor R should use a high-power resistor, and the resistance should ensure the normal operation of the voltage regulator.
Figure (b) has both overvoltage protection and transient overvoltage protection. During normal operation, the tube voltage drop of the FETs J1 and J2 is very low, and the ±VSD value is not large, so the two voltage regulators Dz1, and Dz2 are not working, that is, they are not broken down. When the power supply voltage is too large, the Zener diode is broken down. This not only stabilizes the positive and negative supply voltages of the op amp, but also the reverse regulated current flowing through Dz1 and Dz2 will flow through the FETs J1 and J2. The characteristics of the FET are known to increase the tube drop VDS of J1 and J2, thereby limiting the power supply value applied to the op amp. Capacitors C1 and C2 are used to eliminate the instantaneous pulse voltage because the voltage on the capacitor cannot be abrupt. When the instantaneous pulse voltage comes, if the capacities of C1 and C2 are large, the voltage fluctuations of C1 and C2 will be negligible.
Both circuits can protect the left and right when the single power supply is overvoltage. You can choose according to your needs! 
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