JPS62102314A - Protecting device for microcomputer operation in case of momentary power failure - Google Patents

Abstract

PURPOSE:To minimize the voltage drop of a power source by stopping all loads with a signal from a voltage drop detecting device only when an input voltage is lower than a reference voltage. CONSTITUTION:An operation protecting device for a microcomputer 2 is equipped with the voltage drop detecting device 1, which has a reference voltage required by the microcomputer 2 to operate normally. If the voltage of the power source 5 drops below the reference voltage owing to a momentary power failure, the output signal of the detecting device is inverted. When the microcomputer 2 detects the inversion of the signal, all loads are stopped to begin with loads 3a and 3b. Consequently, the operation of the microcomputer 2 is protected by a capacitor 4 and when the momentary power failure ends, the microcomputer 2 operates the loads 3 according to a predetermined means.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for protecting the operation of a microcomputer in the case of a momentary power outage in a saw tool using a microcomputer.

2. Description of the Related Art In general, appliances using microcomputers are provided with means to prevent the microcomputer from running out of control due to a drop in power supply voltage during a momentary power outage.

In the conventional technology, when the power supply voltage falls below a predetermined voltage, a reset is applied or a voltage backup is performed using a large capacitor.

The problem that the invention aims to solve In the method of resetting a microcomputer, the memory and registers inside the microcomputer are initialized, and the previous state cannot be stored.

In addition, large capacity capacitors are generally large in size, making it difficult to make a 2g device smaller and thinner.

The present invention solves these conventional problems and aims to protect the operation of a microcomputer without resetting it or using a back-up capacitor in the event of a momentary power outage.

Means for Solving the Problems The instantaneous power failure microcomputer operation protection device of the present invention includes a voltage drop detection device that inverts the output when the input voltage becomes lower than a reference voltage, and a voltage drop detection device that inverts the output when the input voltage becomes lower than a reference voltage. This invention is equipped with means for receiving signals and stopping the entire load, and is configured to minimize voltage drops during instantaneous power outages. It receives a signal from an inverting voltage drop detection device and stops the entire load only during the time when the input voltage is below the reference voltage, thereby minimizing the voltage drop in the power supply, thereby protecting microcomputer operation during momentary power outages. It is something to do.

Embodiment FIG. 1 is a block diagram showing an embodiment of the present invention, in which 1 is a voltage drop detection device and 2 is a microcomputer. The voltage drop detection device 1 has a reference voltage that is necessary for the microcomputer 2 to operate normally, and its output signal is connected to the microcomputer 2. Due to a momentary power outage, the voltage of the power supply 5 drops, and the voltage drop detection device 1
When the input voltage of the voltage drop detection device 1 becomes lower than the reference voltage, the output signal of the voltage drop detection device 1 is inverted. When the microcomputer 2 detects that the signal from the voltage drop detection device 1 is inverted, it stops all loads including the loads 3a and 3b.

Generally, the current consumption of the microcomputer 2 alone is extremely small, and the operation of the microcomputer 2 is protected by the capacitor 4. When the instantaneous power outage ends, the input voltage of the voltage drop detection device 1 is higher than the reference voltage, and the output signal is inverted again to notify the microcomputer 2 that the instantaneous power outage has ended. The microcomputer 2 moves the load according to predetermined means.

Effects of the Invention As described above, the microcomputer operation protection device in the event of a momentary power outage of the present invention protects the operation of the microcomputer by stopping the entire load in the event of an instantaneous power outage, thereby preventing a voltage drop in the power supply. It has the excellent effect of easily protecting microcomputer operation in the event of a momentary power outage, without requiring a reset or using a large capacitor.

[Brief explanation of drawings]

The drawing is a (b) road diagram showing one embodiment of the present invention. 1...Voltage drop detection device, 2...Microcomputer (means), 3a, 3b...Load, 4...Smoothing capacitor

Claims (1)

[Claims] In the event of a momentary power outage, the method is characterized by comprising a voltage drop detection device having a function of reversing the output when the input voltage becomes lower than a reference voltage, and means for receiving a signal from the voltage drop detection device and stopping the entire load. Microcomputer operation protection device.