Shown in the figure is composed of operational amplifier delay the release of the relay circuit. When the power switch, the inverting input of op amp plus the resistance of 4.7kO and 10kO divider VT, C1 had a chance to recharge, plus inverting input is low. Therefore, the output of op amp is low and relay. At the same time the power resistor to the capacitor C1 through 1.2MO charge. With the charging capacitor C1, the voltage on it increases gradually over a period of time the voltage on Cl to be high, it is added with the phase input is high, the op amp output is high, following Electric to release. Therefore, this circuit is delay the release of the relay circuit. The length of the delay time by adjusting 1.2MO resistance to change, such as by the map parameters, the delay time is about 260s. Circuits can be relay or solenoid load coils, lights, etc. can also be displayed and alarm devices.