JPH09292853A - Notice circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the battery service life and reduce its cost. SOLUTION: When a pulse signal output from an output port P1 of a controller 3 is Lo, transistors Q2 and Q3 enter OFF state, FETQ1 enters ON state, and charging is performed from a battery 5 to a dielectric capacitor C1. Next, when the pulse signal is Hi, the transistors Q2 and Q3 enter ON state, FETQ2 enters OFF state, and the charge voltage of the dielectric capacitor C1 is superimposed on the battery voltage and is output to a 7-segment LED.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a notification circuit, and more particularly to a notification circuit driven by a dynamic drive system.

[0002]

2. Description of the Related Art Conventionally, in gas appliances, a light emitting diode (LED) is often used as a digital display for displaying the time, set value, etc., and as a display lamp for prompting the battery replacement time by lighting. The light emitting diode operates at a low voltage and a small current and consumes a small amount of current. Therefore, the light emitting diode is widely used for a device using a dry battery as a power source.
Further, there is a dynamic driving method as a method for reducing power consumption. In the dynamic driving method, the light emitting diode is not always supplied with electric power, but by repeatedly supplying and cutting off electric power, the display section is made to blink finely, and it is made to appear as if it is lit by the afterimage effect. Therefore, it is possible to reduce the power consumption as compared with the method of always supplying the power.

FIG. 2 shows a schematic configuration diagram of a conventional notification circuit utilizing such dynamic control. This notification circuit is a battery replacement LED that lights up when the battery life is shortened.
1, a 7-segment LED 2 for displaying the time and the like, a controller 3 for outputting a pulse signal from each of the output ports P1, P2, P3, and a battery replacement LED 1, 7-segment L according to the pulse signal output from the controller 3.
And a drive circuit 4 for supplying / cutting off power to / from the ED 2. The battery voltage Vd is boosted by the booster circuit 7 using the DC / DC converter IC 6 by using the two dry batteries 5 connected in series as the power source, and the boosted voltage Ve is output to the controller 3 and the drive circuit 4.

Battery replacement LED 1 and 7-segment LED
Power is supplied to each of the power supplies 2 from the boosted power supply through the drive circuit 4, and the display is controlled by the display control signal line 8 of the controller 3.

As shown in FIG. 3, the controller 3 outputs the output port P1 when the output of the output port P1 is Hi.
2, the output of P3 is Lo, and the output of the output port P2 is H
If it is i, the outputs of the output ports P1 and P3 are Lo,
When the output of the output port P3 is Hi, a pulse signal that outputs Lo of the outputs of the output ports P1 and P2 is output.

The drive circuit 4 supplies and cuts off power from the boosted power source to the one-digit portion of the 7-segment LED 2 in accordance with the pulse signal output from the output port P1 and the output port P2. A circuit B for supplying / shutting off electric power from the boosted power source to the 2-digit part of the 7-segment LED 2 in accordance with the output pulse signal, and the output port P3.
A circuit C for supplying / shutting off the power from the boosted power source to the battery replacement LED 1 according to the pulse signal output from the
Consists of Since the circuits A, B, and C have the same configuration, only the circuit A will be described here. Circuit A
Includes a transistor Q11 whose base is connected to the output port P1 of the controller 3 via the resistor R11, and a transistor Q12 whose base is connected to the collector of the transistor Q11 via the resistor R12. The emitter of the transistor Q12 is connected to the power supply, and the collector is connected to the 7-segment LED2.

Next, regarding the operation of this annunciation circuit,
This will be described with reference to FIG. When the output of the output port P1 is Lo, the base current does not flow in the transistor Q11 and the transistor Q12 is in the OFF state, and the base current does not flow in the transistor Q12 and the transistor is in the OFF state.
The power supply line to the one-digit part of is cut off. Next, when the output of the port P1 becomes Hi, a base current flows through the transistor Q11 to turn it on, and the transistor Q12
Also, since the base current flows and is turned on, power is supplied to the one-digit portion of the 7-segment LED 2. in this way,
The output port P1, P2, P3 outputs the above-mentioned pulse signal, drives the circuit A, the circuit B, the circuit C, and turns on the LED by the dynamic drive method, so that the power of the LED is higher than that of the method of constantly turning on the LED. The consumption can be reduced to about one third.

As described above, in a circuit using a dry battery as a power source,
It is an issue to suppress the power consumption and prolong the life of the dry battery. Therefore, even if the voltage of the dry battery drops due to use, in the case of two dry batteries, the system is required to be operable up to a battery voltage of about 1.9 to 2.0V. However, since the operating voltage of the light emitting diode needs to be at least about 2.2 to 2.3 V depending on the color, the DC / DC converter I is required to boost the battery voltage.
A booster circuit using C was necessary.

[0009]

However, since only the light emitting diode needs the boosted voltage and the controller normally operates up to about 1.9 to 2.0 V, the battery voltage is boosted to cover the entire system with the boosted voltage. Therefore, there is a problem that the battery life is shortened because an excessive voltage is applied and the controller and the booster circuit consume extra power. In addition, the booster circuit has a DC / DC converter IC.
However, there is a problem that the cost becomes high.

The notifying circuit of the present invention is intended to solve the above problems, improve the battery life, and further reduce the cost.

[0011]

A notification circuit of the present invention for solving the above-mentioned problems includes a display section, a controller for outputting a pulse signal, a battery serving as a power source for the display section and the controller, and a pulse signal for the pulse signal. In a notification circuit including a drive unit that cuts off power supply from the battery to the display unit by one of a high level signal and a low level signal, and supplies the power from the battery to the display unit by the other signal, The drive unit includes a capacitor that is charged from the battery by the one signal of the pulse signal and discharged to the display unit by the other signal, and at the time of discharging, the voltage across the capacitor is superimposed on the power supply voltage. The gist is to apply to the display unit.

In the notification circuit of the present invention having the above-mentioned structure, the controller outputs a pulse signal, and the pulse signal charges the capacitor from the battery with one of a high level signal and a low level signal. Here, when the pulse signal switches to the other signal, the minimum operating voltage of the display unit and the minimum operating voltage of the controller can be balanced by superimposing the voltage across the capacitor on the power supply voltage and applying it to the display unit. Therefore, it is not necessary to boost the voltage in the power supply unit, and it is not necessary to apply an extra voltage to the controller.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In order to further clarify the structure and operation of the present invention described above, preferred embodiments of the alarm circuit of the present invention will be described below. FIG. 1 is a schematic configuration diagram of a notification circuit as one embodiment. Although the basic configuration is the same as that of the notification circuit of the conventional example (FIG. 2), the notification circuit of this embodiment (FIG. 1) does not include the booster circuit 7 using the DC / DC converter IC 6 in the power supply part. The battery voltage Vd is directly supplied to the controller 3 and the drive circuit 4. Moreover, the configuration of the drive circuit 4 is different. The same components as those of the conventional gas stove are designated by the same reference numerals, and the description thereof will be omitted.

The drive circuit 4 has the same circuit D,
Since it consists of E and F, only the circuit D will be described here. The circuit D includes a diode D1, an electrolytic capacitor C1 and an FET that are connected in series between the power supply Vd and the ground.
Q1, a transistor D2 connected in parallel to the diode D1 and the electrolytic capacitor C1, and a transistor Q
A transistor Q3 having a base connected to the collector through a resistor R1 and a transistor Q4 having an emitter connected to the positive side of the electrolytic capacitor C1 are provided. The base of the transistor Q3 is connected to the output port P1 of the controller 3. The collector of the transistor Q4 is connected to the 7-segment LED 2 and the base is connected to the power supply Vd.

Next, the operation of the notification circuit of this embodiment will be described using circuit D. When a pulse signal is output from the output port P1 of the controller 3 and the output is Lo, the base current does not flow in the transistor Q3 and the transistor Q3 is in an OFF state.
The state becomes the F state. Since the transistor Q3 is in the OFF state, the gate voltage of the FET Q1 becomes equal to the battery voltage Vd and is in the ON state, and the diode D is generated by the power supply voltage Vd.
1, the electrolytic capacitor C1 is rapidly charged, and the voltage across the electrolytic capacitor C1 becomes substantially equal to the power supply voltage Vd. At this time, the base current does not flow in the transistor Q4 and the transistor Q4 is turned off.

Next, when the pulse signal output from the port P1 of the controller 3 is switched to Hi, a base current flows through the transistor Q3 to turn it on, and a base current also flows through the transistor Q2 to turn on. Further, since the transistor Q3 is in the ON state, the FET Q1
The gate voltage becomes 0, and it is turned off. Since the transistor Q2 is in the ON state, the potential on the negative side of the electrolytic capacitor C1 becomes equal to the power supply voltage Vd, and the voltage across the electrolytic capacitor is about Vd. Therefore, the potential on the positive side of the electrolytic capacitor C1 is about 2Vd. Become. Therefore, the base current flows through the transistor Q4 to be in the ON state, and the discharge of the electrolytic capacitor C1 causes about 2% of the power voltage.
Double voltage 2Vd is applied to the 7-segment LED 2.

As described above, the pulse signal output from the controller 3 is alternately switched to repeat the above operation, and the display operation of the 7-segment LED 2 by the boosted voltage is performed.

As described above, according to the notification circuit of this embodiment, the power consumption of the LED can be reduced by the dynamic drive system using the pulse signal. DC / D
Since the pulse signal output from the controller 3 is used without using the C converter IC6 and the power supply voltage Vd is boosted by the circuit having a simple configuration using the electrolytic capacitor C1, the diode D1, and the FET Q1, the cost can be reduced. By using the boosted voltage only for the LED 2, it is not necessary to apply an extra voltage to the controller 3, and the minimum operating voltage of the LED 2 and the minimum operating voltage of the controller 3 can be balanced, so that wasteful power consumption can be reduced. . Furthermore, because the boosting function works only while the LED2 is being driven,
It is possible to prevent wasteful power consumption due to the boosting operation even when 2 is not driven.

The embodiments of the present invention have been described above.
The present invention is not limited to these embodiments, and a storage battery may be used instead of the dry battery, for example. In addition, in this embodiment, the pulse signal input to the drive unit is Hi.
When the power is supplied to the display, the pulse signal is Lo
It is needless to say that the circuit may be configured to supply power to the display at that time, and can be implemented in various modes without departing from the scope of the present invention.

[0020]

As described in detail above, according to the notification circuit of the present invention, the minimum operating voltage of the controller is displayed by superimposing the voltage across the capacitor during discharge on the power supply voltage and applying it to the display section. Since the balance can be achieved even if there is a difference in the minimum operating voltage of the parts, it is possible to reduce wasteful power consumption by applying an extra voltage to the controller and improve battery life. In addition, since the boosting operation is not performed while the display unit is stopped by boosting the voltage only when the capacitor is discharged, it is possible to reduce unnecessary power consumption and improve the battery life. Further, the voltage can be boosted with a simple configuration in which the voltage across the capacitor during discharge is superimposed on the power supply voltage, so that the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a notification circuit as an example.

FIG. 2 is a schematic configuration diagram of a conventional notification circuit.

FIG. 3 is a graph showing a pulse signal output from a controller.

[Explanation of symbols]

1 ... Battery replacement LED, 2 ... 7-segment LED, 3
... controller, 4 ... drive circuit, 5 ... dry battery, 6 ...
DC / DC converter IC.

Claims (1)

[Claims] 1. A display unit, a controller that outputs a pulse signal, a battery that serves as a power supply for the display unit and the controller, and one of the high level and low level signals of the pulse signal from the battery to the display unit. In the notification circuit including a drive unit that cuts off the power supply to the display unit and supplies the power from the battery to the display unit by the other signal, the drive unit uses the one signal of the pulse signal by the battery unit. A notification circuit, comprising: a capacitor that is charged from the battery and discharged to the display unit by the other signal, and applies a voltage across the capacitor to a power supply voltage to the display unit when discharging.