UNINTERRUPTIBLE POWER SUPPLY

PURPOSE:To contrive to activate a battery at low temperature and to prevent said battery from overcharge at high temperature by bringing the DC output voltage of a power circuit charging said battery close to the recommended charging voltage curve of the battery with the change of the ambient temperature thereof for varying said DC output voltage. CONSTITUTION:An apparatus is composed of diodes D2-Dn for generating a reference voltage, a resistor R1 passing an electric current for generating a forward voltage drop through said diodes D2-Dn, and voltage divider resistor R2, R3 for obtaining DC voltage with an arbitrary multiplying factor of said reference voltage A power circuit gives a charging voltage to a battery while receiving commercial power, and shows a negative temperature coefficient relative to a temperature change as the effect of its use of the forward voltage drop of said diodes as the reference voltage. That is because the reference voltage has the negative temperature coefficient, the output voltage of said power circuit is high when the temperature is low, and lowers when said temperature becomes higher.