Power source voltage measuring device, temperature detection device equipped with power source voltage measuring device, and temperature controller

The utility model relates to a power source voltage measuring device, a temperature detection device equipped with the power source voltage measuring device, and a temperature controller. The power source voltage measuring device comprises a resistor, a capacitor and a control device, wherein the control device comprises a comparator connected with the capacitor, a reference voltage source connected with the comparator, a timer and a calculation unit, the timer is used for recording a discharging time interval of the capacitor from a fully-charged state to a state that a voltage value of the capacitor detected by the comparator is equal to a voltage value of the reference voltage source, the calculation unit carries out capacitance value calculation to acquire a voltage value of a power source according to the voltage value of the reference voltage source, the time interval, a resistance value of the resistor and a capacitance value of the capacitor. The power source voltage measuring device can use one modul