JPH04216293A - Load controller - Google Patents

Abstract

PURPOSE:To constitute the load controller to individually judge the operational defect of a switch provided for each load without operating the load. CONSTITUTION:As a main switch, a relay RX is provided between a load unit group 24 and a power line 101. An individual contact operation detection part 34 is parallelly connected to a contact (x) of this relay RX. A main contact operation detection part 36 is parallelly connected to the load unit group 24. The defect of the contact (x) is judged by a current flowing in the main contact operation detection part 36 and on the other hand, the defects of respective contacts y1 and y2 in the load unit group 24 are judged by a current flowing in the individual contact operation detection part 34.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load control device, and more particularly to a load control device capable of determining malfunction of a load switch provided for each load.

0002

2. Description of the Related Art In building management systems, home control systems, and the like, load control devices are used to remotely control various load devices (hereinafter referred to as loads).

FIG. 4 shows the configuration of a conventional load control device. In FIG. 4, a plurality of loads (12) are connected in parallel to a power line (10). In order to perform ON/OFF control of this load (12), this load (12) is provided with a relay switch (hereinafter referred to as a relay) (14) for each load. Here, the relay (14) is composed of a contact (14a) that performs switching and a drive section (14b).

[0004] Furthermore, the load (12) and this load (12)
A load unit (16) is constituted by a relay (14) that switches the ing.

[0005] The load unit group configured as described above (
The control in step 18) is performed as follows. That is, Figure 4
The relay drive transistor (22) is turned on by the drive signal from the control unit (20) shown in , and as a result, the relay drive unit (14b) operates. This results in
The contact (14a) closes, power is supplied to the load (12), and the load (12) starts operating.

[0006]

However, in this conventional load control device, the contacts (14) of the relay (14)
There was a problem in that it was not easy to judge defects such as welding in 14a). In other words, in order to properly control the operation of the load, it is necessary to maintain and check the operation of the contacts of the relay (14), but in such cases, the load must be operated each time, which is cumbersome. In addition, there is a problem in that it is difficult to accurately detect contact defects.

[0007] In particular, recently, many loads are often distributed in buildings or homes, and in such cases there is a demand for a device that can easily and remotely inspect each contact for defects. It had been.

The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to turn on/off the operation of each load.
An object of the present invention is to provide a load control device that can remotely and accurately determine malfunction of a controlled switch.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a load unit group in which a plurality of load units each including a load and a load switch for turning ON/OFF the load are connected in parallel to a power line. and a load control device that controls the operation of the load by turning each load switch ON/OFF, a main switch provided between the load unit group and the power line, and connected in parallel with the main switch, a load switch failure detection means that causes current to flow through the load unit group and detects the current when the main switch is open; and load switch failure detection means that is connected in parallel with the load unit group and causes current to flow through the main switch when all the load switches are open. and a main switch failure detection means for detecting the current thereof; and a main switch failure detection means for controlling ON/OFF of each of the load switches and the main switch, and accepting current detection results from the load switch failure detection means and the main switch failure detection means. , and control means for determining malfunction of the load switch and the main switch.

0010

[Operation] According to the above structure, each load switch is inspected for failure as follows. First, the control means closes only the load switch to be inspected. This results in
The load switch failure detection means causes current to flow through the load switch, and the detection result at this time is determined by the control means. In other words, if no current is flowing, it is determined that the load switch to be inspected is defective, that is, it is defective in closing.

On the other hand, when determining that the main switch is defective, first, only the main switch is closed by the control means. As a result, current is caused to flow through the main switch by the main switch failure detection means, and the current detection result at that time is determined by the control means. In this case, if no current is flowing, it is determined that the main switch has a closing failure. Further, failures due to welding of the load switch and main switch are determined by determining the current detection results from the load switch failure detection means and the main switch failure detection means with all the switches open. That is, when all the switches are open, no current normally flows, but if current flows, it is determined from welding or the like.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a relay (RX), which is a component of the main switching section (26), is arranged between the load unit group (24) and one power line (101). Specifically, a contact x of a relay RX is arranged. Here, the load unit group (24) is the load (24) as described above.
8) and a load switch are connected in parallel.

In this embodiment, the load unit is 50
Two units are shown in the figure. Here, a relay RY1 is provided for the load (28), and a relay RY2 is provided for the load (30). In the figure, the contact point of relay RY1 is indicated by y1, and the contact point of relay RY2 is indicated by y1.
The contact point is indicated by y2.

[0015] The main opening/closing part (26) is connected to the load unit group (2
4) performs ON/OFF control of current supply. Therefore, the relay drive transistor Tr1 is connected to the relay RX, and the relay drive transistor Tr1 is connected to the relay RX.
Its operation is controlled by a control section (32) which will be described in detail later.

[0016] Furthermore, the relay RY1 that performs ON/OFF control of the load (28) is controlled by a relay drive transistor Tr2, and also controls the ON/Off of the load (30).
The operation of relay RY2 that performs FF control is controlled by relay drive transistor Tr3. here,
The relay drive transistors Tr2 and Tr3 include a control section (
A relay drive signal is supplied from 32).

In the figure, an individual contact operation detection section (34) is provided in parallel with the relay contact x of the main switching section (26).
When the contact x is opened, a current flows through the load unit group (24) to detect a defective contact of each relay. This individual contact operation detection section (34) is composed of a photocoupler P1, a diode D1, and a resistor R1. Here, the photocoupler P2 detects the current when it flows from the power line (101) to the load unit group (24). Note that the diode D2 is provided to prevent reverse current, and the resistor R2 is provided to prevent overcurrent.

A main contact operation detection section (36) connected in parallel to the load unit group (24) detects malfunction of the contact x. This main contact operation detection section (3
6) is photocoupler P2, diode D2, and resistor R2
It is configured by connecting in series. Here, the photocoupler P2 allows a current to flow from the other power line (102) to the contact x when the contact x is closed, and detects the flowing current. Note that diode D2 and resistor R2
are provided to prevent reverse current and overcurrent, respectively, as described above.

A terminal d of a control section (32) is connected to the collector side of the phototransistor in the photocoupler P1. On the other hand, a terminal e of the control section (32) is connected to the collector side of the phototransistor in the photocoupler P2.
is connected. As a result, the control unit (32) determines the current detection results at the photocouplers P1 and P2.

Between the power lines (101) and (102),
A power supply synchronization circuit (38) is connected. This power synchronization circuit (38) is provided with a photocoupler P3 that detects current in both directions, and thereby determines the zero-crossing point in the AC signal for power supply. The detection pulse at the zero crossing point is sent to the terminal f of the control section (32).

The control section (32) closes each contact during inspection based on the sent detection pulse indicating the zero-crossing point. That is, in this embodiment, the contact is closed during contact inspection near the peak value of the alternating current wave. In other words, by detecting contact defects in a short period of time near the peak value of the alternating current wave, current is not flown unnecessarily through each contact, and defect detection is performed accurately.

The operation of the load control device of this embodiment configured as described above will be explained with reference to FIG. In the following description, in order to simplify the explanation, it is assumed that the two load units shown in FIG. 1 are arranged.

First, in step 201, the control unit (32
) sets its terminals a to c to Lo and turns off all relay drive transistors Tr1 to Tr3. As a result, the contacts x, y1, and y2 of each relay are opened.

In step 202, the level of terminal e in the control section (32) is determined. Here, if the contact point x
If the photocoupler P2 is welded, the light emitting diode in the photocoupler P2 emits light, which causes the potential on the collector side of the phototransistor to drop. Since the terminal e in the control unit (32) is connected to this collector side, the current flowing through the photocoupler P2, that is, the welding of the contact x is detected as a result. Then, when it is determined that the contact x is welded, in step 203,
A display to that effect is displayed on a display section (not shown).

In step 204, similarly to the above, the terminal d
level is determined. Here, if the level is Lo, that is, if either of the contacts y1, y2 is welded or the like and current flows to the photocoupler P1, the control unit (32
), and a message to that effect is displayed on the display section in step 205.

[0026] In step 206, the control unit (32)
Only terminal a is set to Hi, and relay drive transistor Tr1
Turn ON to operate relay RX. Then, the contact x of the relay RX is closed, and as a result, if the contact is normal, current will flow through the photocoupler P2.

In step 207, the photocoupler P
The current flowing through terminal 2 is determined by the level at terminal e. Here, if the level of the terminal e is Hi, it is determined that the contact x is not closed, and in this case, a defect is displayed on the display section in step 208.

At step 209, similarly to the above, only relay RY1 is operated, and contact y1 is closed. Then, in step 210, the control section (32) determines the level of the terminal d. Here, if contact y1 does not close due to some action, photocoupler P
Since no current flows through the terminal 1, the level of the terminal d becomes Hi, and a defect is displayed on the display section in step 211.

In steps 212, 213, and 214, similarly to the above, it is determined that the contact y2 is defective.

Then, in step 215, it is determined whether or not welding or defective contact points have been detected in each of the above steps, and if everything is normal, a message to that effect is displayed on the display section. As described above, the load control device of the present embodiment has the advantage that it is possible to remotely detect and judge contact failures, which could not be done individually in the past, and that it is also possible to accurately detect failures. Therefore, for example, in a building system or a home control system where each load is distributed, each contact point can be inspected extremely easily, and a highly convenient system can be constructed.

FIG. 3 shows the waveforms of each signal in the load control device shown in FIG. 1. put it here,(
A) shows the state of contact y1 or contact y2, and (
B) shows the state of the contact x, and (C) shows the waveform of the signal wave on the power line. Also, in (D),
The output pulse of the power synchronization circuit (36) is shown, (E) shows the state of terminal e in the control section (32), and (F) shows the state of terminal d.

FIG. 3 shows the timing of starting and ending load control, taking into account the relationship between relay RX, which uses a relay with a relatively high withstand voltage, and relays RY1 and RY2, which use relays with a relatively low withstand voltage. It shows the time.

In FIG. 3, when starting load control, contacts y1 and y2 are first closed before contact x to protect contacts y1 and y2. Then, its closure is confirmed by the terminal d of the control section (32).

In this embodiment, considering the time T1 for the contact to completely close, the contact x is closed after the terminal d reaches the Lo level twice. That is, this is to avoid, for example, chattering occurring when the contact is closed, and the contact x being closed in an unstable state. According to such control, it is possible to reliably confirm the closure of the contacts y1 and y2, and furthermore, it is possible to ensure the complete closing time of the contacts y1 and y2, so there is an advantage that each contact can be sufficiently protected.

On the other hand, when the load control is finished, contrary to the above, the contact x is first opened, Lo level is detected twice at the terminal e of the control section (32), and the Lo level is detected at the terminal d. After confirming that the level is Hi level, the contacts y1 and y2 are opened. Similar to the above, such control has the advantage that each contact can be protected and reliable load control can be performed.

[0036] In the above explanation, the focus has been on faulty contacts, but it goes without saying that it is also possible to determine faulty parts such as the drive part of relays, and it is possible to reliably grasp overall malfunctions related to load control. can.

Note that the resistances R1 and R2 in the individual contact operation detection section (34) and the main contact operation detection section (36) are as follows.
It is preferable to use a high-resistance one, and the load control device of this embodiment has the advantage that defects in each contact can be determined based on minute currents. Therefore, it is possible to determine whether a contact is defective by passing a minute current through the load and without operating the load. Further, for example, it is preferable to make the resistor R1 variable and vary it depending on the number of loads. Furthermore, it is also preferable to provide a switch or the like that cuts off the current to the individual contact operation detection section (34) and the main contact operation detection section (36) in cases other than the time of contact failure inspection.

[0038]

As explained above, according to the load control device according to the present invention, malfunctions of load switches connected to each load can be determined individually and reliably. Furthermore, it is possible to detect welding of a load switch, for example, even when the load is not operated, and furthermore, it has the effect that, for example, a failure of the load switch can be detected every time the load is operated. In particular, in building management systems and home control systems where loads are distributed, the operation of each load switch can be comprehensively grasped remotely, making it possible to construct highly reliable and convenient systems. have

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of a load control device according to the present invention.

FIG. 2 is a flowchart showing the process of inspecting each contact for defects.

FIG. 3 is a timing chart showing the waveforms of each signal at the start and end of load control.

FIG. 4 is a circuit diagram showing the configuration of a conventional load control device.

[Explanation of symbols]

(101), (102) Power line (24) Load unit group (26) Main opening/closing part (28), (30) Load (32) Control section (34) Individual contact operation detection section (36) Main contact operation detection section (38) Power synchronization circuit

Claims (1)

[Claims] Claim 1: A load unit comprising a load and a load switch for turning on/off the load, the load unit having a plurality of load unit groups connected in parallel to a power line, and operating the load by turning on/off each of the load switches. In a load control device that performs control, a main switch provided between the load unit group and the power line, and connected in parallel with the main switch,
load switch failure detection means for passing a current through the load unit group and detecting the current when the main switch is opened; and a load switch failure detection means connected in parallel with each of the load unit groups to flow current to the main switch when all the load switches are opened. main switch failure detection means for detecting the current as it flows;
Turn on/off the load switch and the main switch
and a control means that receives current detection results from the load switch failure detection means and the main switch failure detection means and determines malfunctions of the load switch and the main switch. load control device.