| 摘要 |
PURPOSE:To prevent engine starting from becoming impossible by constituting a heater using a battery to automatically break an electric current to the heater when battery voltage becomes below its fixed value. CONSTITUTION:Voltage V1 is generated at the output terminal of a constant- voltage circuit 23 by turning on a switch SW1. Battery voltage V is divided by a variable resistance VR2 and a resistance R9 to generate voltage V4, which is inputted at the irreversible input terminal of a comparator COM2. On the other hand, the voltage V1 is reduced through a reference voltage generating circuit 25 to voltage V5, which is inputted at the reversible input terminal of the comparator COM2. The comparator COM2 compares the two voltages V4 and V5, and in the case of V4<V5, outputs a low level signal to turn on a generating circuit 26, and thereby flashes an indicating lamp LED1 for power source, and moreover turns off a transistor Tr1. The electric current to the heater is thereby broken. Therefore the above constitution lengthens a life of the battery, and prevents engine starting from becoming impossible. |
