| 摘要 |
PROBLEM TO BE SOLVED: To minimize current drain from a power supply by switching the temperature detector in a temperature monitor circuit to be built in the circuit or removed therefrom based on an activation pulse thereby using the temperature detector intermittently. SOLUTION: A thermistor 26 is mounted on the motor casing, a battery 22 is fixed separately from a card and a regulator 24 supplies a stabilized output 5V regardless of the charged state of battery 22. A resistor 30 is connected with a regulated 5V power supply rail and an NPN bipolar transistor 32 is connected in series between the resistor 30 and thermistor 26. The transistor 32 is fed, to the base thereof, with an activation pulse from a preprogrammed microprocessor 14. The microprocessor 14 switches the thermistor 26 to be built in the circuit or removed therefrom and produces an activation pulse signal which is delivered to the transistor 32 thus limiting the current drain from the regulator 24. |
