| 摘要 |
PURPOSE: To provide an electric power supply circuit of a portable equipment which has no trouble of data destruction by misoperation of switches and which is small-sized since it uses only a small number of components. CONSTITUTION: A circuit for supplying power to a main body of a portable equipment SYS from a battery power supply is provided with a reset circuit RS and a delay circuit DL. When a switch SW is pressed once for turning the power on, a resistor Q2 is turned on through a diode D1 and resistors R3, R4 and then the main body of the portable equipment is powered on through a terminal T2. At that time, a collector of a transistor Q1 drives the reset circuit and the delay circuit and thereby a microcomputer built in the main body of the equipment is reset and then the main body SYS starts its operation. With the switch pressed one more time, delay signals are sent out from the delay circuit after the passage of time for which the microcomputer conducts a specified saving process and then a transistor Q3 is turned on and the transistors Q2 and Q1 are turned off and thereby the power is turned off. |
