JPH0923577A - Neon lamp driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to use a neon lamp over a long period of time even if it has a short flashing cycle by driving the neon lamp by the on-control of a transistor. SOLUTION: First, a resistor 4e connected to a microcomputer 1 and a photodiode 2a of a photocoupler 2 are driven and thereby a photo transistor 2b comes to an on-state. When the photo transistor 2b comes to an on-state, base current of a transistor 7 flows and then a transistor 7 comes to a continity-state' and thereby a neon lamp 3 lights up, diodes 5a-5d full-wave rectify AC voltage from an AC commercial power supply 10. The resistor 4a limits the current in the neon lamp 3 and thereby protects the neon lamp 3. In this manner, the neon lamp 3 can be driven without installing a circuit for controlling a contact such as a relay and a TRIAC.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a neon lamp driving device for driving a neon lamp that externally indicates a failure or abnormal state of a showcase or the like, as a control device for a refrigerating showcase, a freezing showcase or the like.

[0002]

2. Description of the Related Art In a conventional neon lamp driving device, for example, as shown in FIG. 3, a contact 14 of a circuit to which an AC commercial power source 10 and a neon lamp 3 are connected is controlled to be turned on and off as an output device of a microcomputer 1. The neon lamp 3 is driven by driving the relay 18 by the transistor 16 that controls the opening and closing.

[0003]

As described above, since the conventional neon lamp driving device drives the neon lamp 3 by using the relay 18, if the blinking cycle of the neon lamp 3 is set to be short, the life of the relay 18 is shortened. However, there is a problem that the driving device cannot be used for a long period of time because it runs out quickly.

On the other hand, although not shown, the above-mentioned relay 18
Even if a triac is used instead of, a circuit for controlling the triac is required. In addition, when a triac is used, leakage current flows from the snubber circuit for triac protection, and the leakage current causes
The neon lamp sometimes turned on regardless of a malfunction or abnormal condition of the refrigerated showcase or the like.

It is an object of the present invention to provide a neon lamp driving device which has a simple structure and can be used for a long period of time even if the blinking cycle of the neon lamp is short.

[0006]

According to the present invention, a neon lamp connected to a power source is used to output a signal in accordance with a predetermined program by using an output device connected to a microcomputer, whereby the neon lamp is provided. In a neon lamp driving device for controlling blinking, a transistor is connected to the output device, a voltage obtained from the power source is rectified, and the neon lamp and the transistor are connected via the rectified power source. A neon lamp driving device is provided which drives the neon lamp by controlling the on / off of the transistor.

According to the present invention, there is also provided a neon lamp driving device characterized in that the rectification is full-wave rectification.

Further, according to the present invention, there is provided a neon lamp driving device characterized in that the rectification is half-wave rectification.

Furthermore, according to the present invention, there is provided a neon lamp driving device characterized by using a photo coupler as an output device of the microcomputer.

That is, according to the present invention, the neon lamp connected to the power source is controlled to blink by outputting a signal according to a predetermined program by using an output device connected to the microcomputer. In a neon lamp driving device for use in the same, a photocoupler as an output device connected to the microcomputer, a transistor whose base terminal is connected to a light receiving element of the photocoupler and whose collector terminal is connected to the neon lamp. And a diode for full-wave rectifying or half-wave rectifying the AC voltage obtained from the power source.

[0011]

The neon lamp driving device of the present invention can drive the neon lamp without providing the above-mentioned relays or other contacts or the circuit for controlling the triac.

The brightness of the neon lamp can be changed by changing the blinking cycle of the neon lamp.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A neon lamp driving device according to an embodiment of the present invention will be described in detail below with reference to the drawings.

A circuit diagram of a neon lamp driving device according to a first embodiment of the present invention is shown in FIG.

A major feature of the neon lamp driving device of the present embodiment is that a transistor is connected to the output device of the microcomputer to perform full-wave rectification of the AC voltage obtained from the commercial power supply, and then the commercial power supply after full-wave rectification is used. The neon lamp is connected to the transistor, and the neon lamp is driven by the on / off control of the transistor.

That is, in the neon lamp driving device of this embodiment, as shown in FIG. 1, a microcomputer 1, a resistor 4e connected to the microcomputer 1, and this resistor 4e as an output device of the microcomputer 1. Connected to the photodiode 2a and the phototransistor 2
b, a transistor 7 whose base terminal is connected to the emitter terminal of a phototransistor 2b of this photocoupler 2, and a neon lamp connected to the collector terminal of this transistor 7 via a resistor 4a. 3 and diodes 5a, 5b, 5c and 5d for full-wave rectifying the AC voltage obtained from the AC commercial power supply 10.
, A capacitor 6 and a resistor 4b, and resistors 4c and 4d for circuit protection.

Now, the operation of the neon lamp driving device of this embodiment will be described. First, the resistor 4e connected to the microcomputer 1 and the photodiode 2a of the photocoupler 2 are driven, and the phototransistor 2b is turned on. Becomes

When the phototransistor 2b becomes conductive, the base current of the transistor 7 flows, and the transistor 7 becomes conductive. Therefore, as a result, the neon lamp 3 is turned on. The diodes 5a, 5
b, 5c, and 5d perform full-wave rectification on the AC voltage obtained from the AC commercial power supply 10. Further, the resistor 4 a limits the current flowing through the neon lamp 3 to protect the neon lamp 3.

As described above, according to the neon lamp drive device of the present embodiment, the neon lamp 3 is not provided without providing a circuit for controlling the contacts such as the relay or the triac described above.
Can be driven.

The blinking cycle of the neon lamp 3 is set to, for example, 1 second O by a program in the microcomputer.
N, 1 second OFF.

In the neon lamp driving device of the present embodiment, it is not necessary to worry about the life of the relay or the like. Therefore, even if the program in the microcomputer is changed to shorten the blinking period of the neon lamp 3, it is used for a long time. it can. Therefore,
By changing the blinking cycle of the neon lamp 3, it is possible to change the brightness of the neon lamp 3.

The photocoupler 2 is used as the output device of the microcomputer 1 in order to improve the insulation between the drive unit of the neon lamp 3 and the microcomputer 1, and the photodiode 2a and the phototransistor 2b. Since signals are exchanged between them by light, it is possible to prevent external noise invading from the AC commercial power source 10 or electrical noise generated in the drive section of the neon lamp 3 from affecting the microcomputer 1. is there.

A circuit diagram of a neon lamp driving device according to a second embodiment of the present invention is shown in FIG.

The basic structure of the neon lamp driving device of this embodiment is substantially the same as that of the neon lamp driving device of the first embodiment described above, and the description of the same parts is omitted.

A major feature of the neon lamp driving device of the second embodiment is that the AC voltage obtained from the AC commercial power source 10 is half-wave rectified, and the neon lamp 3 is rectified via the AC commercial power source 10 after the half-wave rectification. Is to drive.

That is, the neon lamp driving device of the second embodiment has a diode 5a for half-wave rectifying the AC voltage obtained from the AC commercial power source 10, as shown in FIG.

The neon lamp driving device of the second embodiment is
Unlike the first embodiment described above, the diodes 5b, 5
Although c and 5d are not provided, it is easily understood that the same effect as that of the first embodiment can be obtained.

[0028]

As described above, according to the neon lamp driving device of the present invention, it is possible to provide a neon lamp driving device having a simple structure that can be used for a long period of time even if the blinking cycle of the neon lamp is short. can do.

The brightness of the neon lamp can be changed with a simple structure.

Further, unlike the conventional neon lamp driving device, since no contact is provided, a highly reliable neon lamp driving device can be obtained.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a neon lamp driving device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a neon lamp driving device according to a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a conventional neon lamp driving device.

[Explanation of symbols]

 1 Microcomputer 2 Photocoupler 2a Photodiode 2b Phototransistor 3 Neon lamp 4a Resistor 4b Resistor 4c Resistor 4d Resistor 4e Resistor 5a Diode 5b Diode 5c Diode 5d Diode 6 Capacitor 7 Transistor 10 AC commercial power supply

Claims (6)

[Claims] 1. A neon lamp driving device for controlling blinking of the neon lamp by outputting a signal according to a predetermined program to an neon lamp connected to a power source using an output device connected to a microcomputer. In, connecting a transistor to the output device, rectifying the voltage obtained from the power source, and connecting the neon lamp and the transistor via the rectified power source,
A neon lamp driving device, wherein the neon lamp is driven by on / off control of the transistor. 2. The neon lamp driving device according to claim 1, wherein the rectification is full-wave rectification. 3. The neon lamp driving device according to claim 1, wherein the rectification is half-wave rectification. 4. The neon lamp driving device according to claim 1, wherein a photocoupler is used as the output device. 5. A neon lamp driving device for controlling blinking of the neon lamp by outputting a signal according to a predetermined program to the neon lamp connected to a power source using an output device connected to a microcomputer. , A photocoupler as an output device connected to the microcomputer, a transistor whose base terminal is connected to the light receiving element of the photocoupler and whose collector terminal is connected to the neon lamp, and And a plurality of diodes for full-wave rectifying the generated AC voltage. 6. A neon lamp driving device for controlling blinking of the neon lamp by outputting a signal according to a predetermined program to the neon lamp connected to a power source using an output device connected to a microcomputer. , A photocoupler as an output device connected to the microcomputer, a transistor whose base terminal is connected to the light receiving element of the photocoupler and whose collector terminal is connected to the neon lamp, and And a diode for half-wave rectifying the generated AC voltage.