JPH0151872B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an automatic flashing device for a lighting load, which is suitably used for street lights and the like.

[Background technology]

Conventionally, this type of device detects the amount of external light as a change in impedance using a light amount detection means such as CdS, and applies a voltage corresponding to the change to the switch control unit to open and close a bimetal switch to automatically control the lighting load. It's blinking.

However, in such devices, the bimetallic switch opens and closes slowly, making contact between the contacts unstable, and furthermore, the contact pressure becomes almost 0 near the point where the bimetallic switch's contact opens or closes. Because of this, the contacts are left in an unstable state for a long period of time, shortening their lifespan.

In addition, changes in the amount of external light are extremely irregular;
Pulsations may occur due to the presence of clouds, etc., and if such pulsations occur when the contacts are in an unstable region, they can cause the lighting load to flicker unnecessarily.

Therefore, in order to solve this problem, a bimetal switch is constructed with a so-called jump spring.
Switches with hysteresis characteristics have been developed.

However, with such a bimetal switch, it is not possible to provide a mechanism to compensate for the ambient temperature, and as a result, the amount of heat generated by the bimetal switch's heater fluctuates in response to changes in ambient temperature, making operation unstable. . Furthermore, if the bimetal switch mechanism is constructed in a jump-type manner, there are problems such as the structure of the device becoming complicated.

[Purpose of the invention]

The present invention was made in view of the above circumstances, and it is an object of the present invention to provide a new electronic automatic flashing device that can be configured without using a switch spring mechanism. To provide an automatic flashing device for a lighting load, which eliminates an unstable state by reliably opening and closing a switch when the amount of external light reaches a predetermined operating level even when the amount of external light changes.

[Disclosure of the invention]

The configuration of the present invention will be explained below.

FIG. 1 is an embodiment diagram showing the basic configuration of the present invention.

In the figure, 1 is a main switch for blinking a lighting load 2, 3 is a power source, 4 is a light amount detection means, 5 is an auxiliary switch control section, 6 is a voltage variable circuit section including an impedance element 7, and 8 is a main switch. The switch control section 9 indicates an auxiliary switch.

To explain the basic operation of the present invention, the amount of external light is detected by the light amount detection means 4 and its impedance is varied, so that the voltage supplied from the power source 3 to the auxiliary switch control section 5 reaches the operating level of the auxiliary switch 9. When the voltage is reached, the auxiliary switch 9 opens and closes to operate the voltage variable circuit section 6. Then, the voltage supplied to the auxiliary switch control section 5 instantly increases or decreases, and the auxiliary switch 9, which is in the open or closed state, is further operated in the biasing direction, and the switch 9 is brought into a stable state. let As a result, the main switch control section 8 is supplied with a drive voltage that exceeds the operating level of the main switch 1, and the main switch 1 opens and closes to cause the lighting load 2 to blink reliably.

FIG. 2 shows the operating sequence of the present invention, and FIGS. 3a and 3b show operating characteristic diagrams of the auxiliary switch in the present invention.

3a and 3b show the voltage variable circuit section 6.
This is a diagram showing the change in the driving force f that the auxiliary switch 9 receives due to the function of the switch 9 in response to the amount of external light X. In particular, the diagram in FIG. 3a shows that the driving force of the auxiliary switch increases as the amount of external light increases. Characteristic diagram,
Fig. 3b shows a characteristic diagram in which the driving force of the auxiliary switch decreases as the amount of external light increases, and the present invention can realize any of the characteristics as will be clear from the examples described later. .

In the present invention, as shown in these figures, when the amount of external light X reaches a predetermined level (X1, Since the values F1 and F2 at the time of slight opening or contact are instantaneously increased or decreased by △F, once the auxiliary switch 9 reaches the open or closed state, it instantly shifts to a stable state and becomes unstable. Stable conditions are avoided.

In the figure, - indicates a state in which the auxiliary switch switches from closed to open (or from open to closed) - indicates a state in which the auxiliary switch switches from open to closed (or from closed to open). It exhibits such hysteresis characteristics.

FIG. 4 shows a modification of the embodiment shown in FIG. 1, in which the auxiliary switch 9 is replaced by transistors Tr1 and Tr2.
The auxiliary switch control section 5 is composed of a Zener diode ZD connected in series to resistors R1 and R2, and this Zener diode ZD determines the operating level of the transistor Tr2. are doing. Also, D is AC power supply
This is a rectifier diode installed to rectify the EL and obtain power to drive the non-contact circuit.

To explain the operation of this example circuit, when the amount of external light increases, the impedance of CdS decreases, so the Zener diode ZD breaks over and transistor Tr2 turns on, and the transistor
Tr1 is turned off and the voltage variable circuit section 6 is activated. That is, since the transistor Tr1 is turned off, the resistor Rt connected in parallel to the switch control section 5 is disconnected, and the voltage applied to the switch control section 5 further increases rapidly, and the transistor Tr1 is completely turned off at once. Transition to off state. When the transistor Tr1 is turned off, no voltage is supplied to the relay coil RC, so its contact SW opens to ensure that the incandescent lamp La is turned off.

On the other hand, when the amount of external light decreases, the impedance of CdS increases, so the voltage applied to the switch control unit 5 decreases, the Zener diode ZD turns off, the transistor Tr2 turns off, the transistor Tr1 turns on, and the voltage The variable circuit section 6 is activated. That is, since the transistor Tr1 is turned on, the resistor Rt is connected in parallel to the switch control section 5, the voltage applied to the switch control section 5 further decreases rapidly, and the transistor Tr2 is completely turned off at once. . Therefore, the voltage of the power supply 3 is applied to the relay coil RC, thereby surely lighting the incandescent lamp La.

5 and 6, an auxiliary switch control section 5 is connected in parallel to the light amount detection means 4 to form a part of the voltage dividing circuit of the power supply 3. In particular, FIG. 5 shows the light amount detection means 4. A voltage dividing circuit is shown in which a voltage dividing resistor R1 is connected in series to the parallel connection body of the means 4 and the auxiliary switch control section 5.

Further, FIG. 6 shows a series connection body of the light amount detection means 4 and the auxiliary switch control section 5, and the main switch control section 8.
are connected in parallel, and a resistor R1 is connected to these parallel connections.
An example is shown in which the voltage divider circuit of the power supply 3 is configured by connecting the two in series. When the voltage variable circuit section 6 is activated, the bimetal switch BS1 opens and closes, and the heater
For the series connection body of RH1 and CdS, heater RH
2 are connected and disconnected in parallel.

In FIG. 7, a resistor Rt and heaters RH1 and RH2 are connected in series to the light amount detecting means 4, and the resistor Rt is connected or disconnected by opening or closing an auxiliary switch 9. In FIG.

Furthermore, in configuring the device of the present invention, a timer circuit may be added to forcibly turn off the light after a certain period of time after the lighting load is turned on by the switch means. This results in
In the case where the lighting load is, for example, a street light, it goes without saying that the lights can be turned off from late night until early morning, when there are almost no people on the streets, to save power.

FIGS. 8 to 11 show examples in such a case. In these embodiments, the main switch 1 is designed to perform a timed operation, and a timer circuit T is provided for this purpose.

That is, in FIG. 8, the contact SW is closed only during the set time of the timer circuit T.
In FIG. 9, timer circuit T is timer ICT1
The conduction time of the transistor T2 is set.

Furthermore, in FIG. 10, the timer circuit T is
It is constructed using a photothyristor PhT, and the turn-on time can be set in advance. Further, in FIG. 11, the bimetal switch BS2 constituting the main switch 1 can be closed only when the heater RH is heated by the timer circuit T.

In each of the above embodiments, the input terminals of the timer circuit T may of course be directly connected to both ends of the CdS.

It goes without saying that the switch means in the present invention can be applied to either contact or non-contact switch means in addition to the embodiments described above.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to avoid the unstable opening/closing condition of the switch means that operates in response to slow changes in the amount of external light without using a switch with a jump spring mechanism, and to reduce the lighting load. Flashing operation can be performed reliably.

Furthermore, when a contact switch is used as the switching means, it is possible to effectively prevent arc discharge between the contacts and extend the life of the contacts.
A highly reliable automatic flashing device for lighting loads is obtained.

[Brief explanation of drawings]

FIG. 1 is an embodiment diagram showing the basic concept of the present invention.
FIG. 2 is a flowchart showing the operating sequence of the present invention, FIGS. 3a and 3b are operational characteristic diagrams of the auxiliary switch in the present invention, and FIGS. 4 to 11 are electrical diagrams of other examples of the device of the present invention. It is a circuit diagram. 1...Main switch, 2...Load, 3...Power supply,
4... Light amount detection means, 5... Auxiliary switch control section, 6... Voltage variable circuit section, 7... Impedance element, 8... Main switch control section, 9... Auxiliary switch control section.

Claims (1)

[Scope of Claims] 1. An automatic flashing device for a lighting load that automatically flashes a lighting load by sensing the amount of external light, comprising: (a) a main switch that flashes the lighting load; (b) an opening/closing operation of this main switch; (c) A light amount detection means that changes the impedance according to the amount of external light. (d) A main switch control section that is inserted between the main switch control section and the power source.
an auxiliary switch that opens and closes when the voltage supplied through the light amount detection means reaches the operating level; (e) an auxiliary switch control unit that opens and closes this auxiliary switch; (f) once the auxiliary switch is opened or closed; An automatic flashing device for a lighting load, comprising a voltage variable circuit section that instantaneously changes a drive voltage supplied to a switch control section of the auxiliary switch to further operate the auxiliary switch in the energizing direction. 2. The automatic flashing device for a lighting load as claimed in claim 1, wherein the main switch operates in a timed manner.