JPS62259390A - Optoelectric automatic flasher - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a photoelectric automatic blinker for automatically blinking lighting equipment such as street lights and security lights.

Conventional technology FIG. 2 shows a circuit diagram of a conventional photoelectric automatic flasher.

In this FIG. 2, reference numeral 21 denotes an optical sensor in which an AC voltage 6 is also connected in parallel to 22, and whose resistance value changes depending on the amount of light.

The optical sensor 21 includes a diode bridge circuit 23 and a resistor 2.
4 series circuits are connected in parallel, and a capacitor 25 and a reed relay are connected between the intermediate connection points of the diode bridge circuit 23.
A parallel circuit with the file 26 is connected. Also, resistance 2
One end of 4 is connected to the gate terminal of a bidirectional thyristor 30 via a capacitor 27, a resistor 28, and a reed relay contact 29. 32 is a bidirectional thyristor 3o, and a capacitor 33 is connected in parallel to the bidirectional thyristor 3o.
is a load connected in series with

In the above configuration, when the resistance value of the optical sensor 21 changes depending on the amount of light incident on the optical sensor 21, the current flowing through the excitation coil 26 of the reed relay changes, opening and closing the contact 29, and as a result, the bidirectional thyristor 30 is turned on and off, and the load 32 is blinked. Problems to be Solved by the Invention In the above configuration, if the resistance value of the resistor 28 is small, the inrush gate current that flows when the contact 29 is turned on is large.
There was a drawback that the contact point 29 was welded.

On the other hand, if the resistance value of the resistor 28 is large, a gate signal is required every half cycle when used in an AC circuit, but the gate current at this time is suppressed and the bidirectional thyristor is turned on as a result. requires a high gate voltage. The voltage difference between this maximum gate voltage and the voltage between the main terminals of the bidirectional thyristor 30 when the bidirectional thyristor 3o is turned on becomes the fluctuating voltage of the load circuit of the photoelectric automatic flasher. There was a drawback that it caused a large inrush current.

Means for Solving the Problems In order to solve the above problems, the present invention provides an optical sensor whose resistance value changes according to changes in the amount of light, a transistor that is turned on and off by the voltage between the terminals of this optical sensor, and this transistor. The excitation coil of the relay is connected in series with the
The device includes a thyristor connected in series to a load, and a series circuit of a coil and a contact of the reed relay connected to the gate terminal of the thyristor.

Function: With the above configuration, the inrush gate current that flows when the reed relay contacts are turned on is significantly suppressed by the coil, the contacts do not weld, and the thyristor can be turned on with a low gate voltage.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIG.

In FIG. 1, 1 is an AC power source, to which a surge absorber 2 is connected. This surge absorber 2 has a diode 3. Resistance 4. A series circuit of Zener diode 5 is connected in parallel, and a capacitor 6 is connected to Zener diode 6.
are connected in parallel. As a result, a half-wave rectified voltage is obtained across the capacitor 60. Resistor 7 is connected to capacitor 6.
The series circuit of the optical sensor 8 and the optical sensor 8 are connected in parallel. The optical sensor 8 probably uses a sensor whose resistance value increases as the amount of light decreases.A series circuit of resistors 9 and 10 is connected in parallel to the resistor 7, and a capacitor 11 is connected in parallel to the resistor 1o. The base and emitter of the transistor 12 are connected. The collector of the first transistor 12 is a resistor 1
3 to one end of the optical sensor 8, and also to the pace of the second transistor 14. 1
A resistor 5 is connected between the connection point between the optical sensor 8 and the resistor 9 and the collector of the second transistor 14 .

An excitation coil 15a of a reed relay is connected to the collector of the second transistor 14. A contact 16b of the reed relay is connected to a gate terminal of a bidirectional thyristor 18 via a coil 17.

19 is a capacitor connected in parallel to the bidirectional thyristor 18, and 20 is a load connected in series to the bidirectional thyristor 18.

In the above configuration, when the incident light of the photoelectric sensor 8 gradually changes from a bright state to a dark state by seconds, the resistance value of the optical sensor 8 gradually becomes smaller, and the branch voltage with the resistor 7 becomes lower.

When this branch voltage becomes low, the first
The base voltage of the transistor 12 becomes low, and the first transistor 12 turns off.

By turning off the first transistor 12, the base voltage of the second transistor 140 increases, and the second transistor 14 turns on.

By turning off the second transistor 14, a current flows through the excitation coil 16a of the reed relay, the contact 16b of the reed relay closes, and the gate current of the bidirectional thyristor 18 flows.

This gate current turns on the bidirectional thyristor 18, and the load current flows.If the load 20 is a circuit that has a component that easily causes inrush current, such as a capacitor or an incandescent lamp, the gate current of the bidirectional thyristor 18 turns on. Ff, VJ, If the coil 17 is not present, the inrush current will rise steeply and weld the contact 16b of the reed relay, but by inserting the coil 17, the inrush current will rise gradually and the inrush current will rise at the contact 16b. Welding is prevented. Furthermore, the gate resistance component also increases from the coil 17. Alternatively, a resistance of several tens of ohms is connected to the coil 17, and a sufficient gate current is obtained without suppressing the gate current, so that the bidirectional cystor 18 is turned on in a state where the gate voltage is low.

As a result, there is no fluctuation in the voltage of the load 20, and a stable load current can be obtained.

Effects of the Invention As described above, according to the present invention, it is possible to prevent welding of the reed relay contacts due to inrush gate current, and to turn on the thyristor in a state where the gate voltage is low.
As a result, there is no load voltage fluctuation and a stable load current is obtained.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a photoelectric automatic flasher showing an embodiment of the present invention, and FIG. 2 is a circuit diagram of a conventional photoelectric automatic flasher. 8... Optical sensor, 12... First transistor, 14... Second transistor, 16a...
... Reed relay coil, 16b... Reed relay contact, 17... Coil, 18...
...Bidirectional thyristor, 20...Load. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 1 Display of the case 1985 Patent Application No. 85380 2 Name of the invention Photoelectric automatic blinker 3 Person who makes amendments Relationship to the case Patent application Address 1006 Kadoma, Kadoma City, Osaka Prefecture Name Name
(582) Matsushita Electric Industrial Co., Ltd. Representative Tani
Akio I 4 Agent 571 Address 6, Matsushita Electric Industrial Co., Ltd., 1006 Oaza Kadoma, Kadoma City, Osaka Contents of amendment (1) "32 is bidirectional" on page 2, line 9 of the specification has been changed to "32 is bidirectional." 3
1 is bidirectional”K correction. (2) In the same book, page 2, line 10, change “capacitor 33” to “
The capacitor, 32, is corrected to ``.

Claims (1)

[Claims] An optical sensor whose resistance value changes according to changes in the amount of light, a transistor that is turned on and off by the voltage between the terminals of this optical sensor, an excitation coil of a reed relay connected in series to this transistor, and an excitation coil connected in series to a load. A photoelectric automatic flasher comprising: a thyristor; and a series circuit of a coil and a contact of the reed relay connected to a gate terminal of the thyristor.