JPH0442729A - Power supply controller for electronic appliance - Google Patents

Abstract

PURPOSE:To decrease unnecessary base current of a power supply transistor after turn ON of power supply by switching the state retaining current of a power conducting means between power ON state and steady state thereby reducing current consumption at a power supply control section. CONSTITUTION:When a power switch 11 is turned ON, current is fed to the base resistor 13 of a power supply transistor 12 which is thereby turned ON to feed power from a battery 14 to the circuit part 15 of an electronic appliance. Consequently, the circuit part starts operation to turn a power retaining means, i.e. a transistor 17, ON so as to turn a circuit part 19 ON. After turn ON of the transistor 17, the transistor 17 retains the state of the transistor 12 even if the power switch 11 is turned OFF thus retaining ON state of power supply. Under steady state after turn ON of power supply, unnecessary base current of the power supply transistor 12 can be decreased by means of a resistor 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a switching system for a power supply control device for electronic equipment.

[Conventional technology]

As shown in the circuit diagram shown in FIG. 2, a conventional power supply control device for an electronic device operates as a power source by turning on a power switch 21 to flow a current through the base resistor 23 of a transistor 22 for power supply and turning on the transistor 22. Battery 2 which is
4 to the circuit section 25 of the electronic device.

[Problems to be Solved by the Invention] However, in the conventional technology described above, since general electronic equipment requires a large current when the power is turned on, it is necessary to secure a large amount of base current of the transistor for power supply. In the steady state after being turned on, more base current than necessary flows, resulting in a problem that the current is wasted. SUMMARY OF THE INVENTION The present invention is intended to solve these problems, and its purpose is to provide a method for reducing unnecessary base current of a power supply transistor after power is turned on.

[Means for Solving the Problems] A power supply control device for electronic equipment according to the present invention includes: a) a power supply means for supplying electric power in a power supply control method for turning on and off the power supply of the electronic equipment; and C) the above power supply means. d) power holding means for maintaining the state of the power conducting means; and e) power switch means for turning on and off the power and maintaining the state of the power conducting means. It is characterized by reducing the current consumption of the power supply control unit by switching the current between when the power is on and when the power is on and in a steady state.

[Example] FIG. 1 is an electrical circuit diagram in an embodiment of the present invention.

By turning on the power switch 11, which is a power switch means, current is passed through the power supply transistor 120, which is a power conduction means, and the base resistor 13, and the transistor 12 is turned on.
By turning on, power is supplied from the battery 14, which is a power source means, to the circuit section 15 of the electronic device. When the circuit section of the electronic device receives power, it starts operating and turns on the circuit section 19 to turn on the transistor 17, which is a power holding means.

After the transistor 17 is turned on, even if the user of the electronic device including the present invention as a power supply control circuit releases the power switch 11, the power remains on because the transistor 17 maintains the state of the transistor 12.

When the user turns on the power switch 11 again, the circuit section 18 of the electronic device detects that the power switch 11 has been pressed and turns off the circuit section 19, which turns off the transistor 17 and turns off the power supply transistor 12. Turn off. As a result, the power supply from the battery 14 is cut off and the power is turned off.

Here, since an electronic device such as a boat requires a large current when the power is turned on, it is necessary to set the base resistor 13 to a small value in order to secure a large amount of base current of the transistor 12 for power supply. However, in the steady state after the power is turned on, there is often no need for such a large current as when the power is turned on, and more base current than necessary flows, resulting in wasted current consumption. Therefore, in the present invention, the resistance is 1 in the steady state after the power is turned on.
6 limits the base current of the transistor 12, thereby reducing the unnecessary base current of the power supply transistor after the power is turned on. In other words, the resistance is 13 when the power is turned on, and the resistance is 1 in the steady state after the power is turned on.
6. By switching the base current supply resistance of the power supply transistor 12, the current consumed by the base resistance can be reduced.

[Effects of the Invention] As described above, according to the present invention, by switching the base resistance of the power supply transistor between when the power is turned on and in the steady state after the power is turned on, consumption that is unnecessarily consumed by the base resistance can be reduced. This has the effect of reducing the current.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram showing an embodiment of a power supply control device for electronic equipment according to the present invention. FIG. 2 is an electric circuit diagram showing a conventional power supply control device for electronic equipment. Power supply switch Power supply transistor Base resistor of power supply transistor Battery Base resistor for switching circuits of electronic equipment Power retention transistor Applicant Seiko Epson Corporation Attorney Kizobe Tsuchi Suzuki (and one other person) Figure 1

Claims (1)

[Scope of Claims] A) a power supply control system for turning on and off the power of an electronic device, b) a power supply means for supplying electric power, and c) a power conduction means for coupling the power supply means and a circuit section of the electronic device. d) power holding means for maintaining the state of the power conducting means; and e) power switch means for turning the power on and off, and controlling the power by switching the current that maintains the state of the power conducting means between when the power is on and in a steady state. A power supply control device for electronic equipment, characterized by reducing current consumption of the parts.