JPH0821281B2 - Relay controller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relay control device used for controlling energization of an AC power supply to a load such as a heater.

2. Description of the Related Art Conventionally, a relay control device of this type has a configuration as shown in FIG. In FIG. 6, the AC power supply 1 is connected to the load 2
A relay contact 6 for energizing the
It is configured to operate via the relay coil 3 driven by the relay contact operating means 4. After operating the relay contact 6, the relay contact 6 is passed through the relay contact detecting means 5.
The operating time measuring means 7 measures the time until it detects that the device has actually operated. Specifically, in the input circuit configuration shown in FIG. 7, whether the AC power supply 1 is energized to the load 2 via the contact 6 of the relay is detected by the resistors 13, 14, the diode 15 and the conversion circuit 17. ing. That is, when the contact 6 is closed, the AC waveform shown in FIG. 8a is generated at the point a in FIG. 7, and the resistors 13 and 14 and the diode 15 shape the waveform of FIG. 8a into the waveform of FIG. 8b. To do. A conversion circuit 17 for converting the waveform b shown in FIG. 8 into the waveform c.
Outputs a high voltage only for a certain range of voltage levels when the voltage changes from high to low or low to high. Further, it also outputs a high voltage with respect to the voltage generated at the input side of the conversion circuit when the relay contact 6 is closed. With the configuration shown in FIG. 7, as shown in FIG. 9, the input d to the microcomputer or the like with respect to the output b to the relay coil 3 can be obtained, and therefore the movement of the relay contact 6 can be recognized. That is, the output b to the relay coil 3 is a relay contact drive output, while the relay contact input c is obtained by the input d to the microcomputer or the like. That is, input d
There is always a time t _a which is a high voltage is judged that the time when the relay contact 6 has actually turned on, the time difference between the two is actually operating time of the relay contacts 6 required.

Further, the operation phase of the relay contact operating means 4 is determined based on the measurement time obtained by the operation time measuring means 7 so that the next ON / OFF operation of the relay contact 6 is performed at the optimum phase. ing.

In this way, it is necessary to pay attention to the operating phase of the relay contact 6, as shown in FIG. 10, when the relay contact 6 is turned off, the phase at which the relay contact 6 operates with respect to the half-wave phase of the AC power supply. Arc sparks are generated in the remaining phase (shaded area) of the phase a or the phase b. In order to prevent deterioration of the relay contact 6 as much as possible, the AC power supply should be reduced as much as possible. This is because it is desirable to turn on / off in the vicinity of the zero cross phase of and in the phase before the zero cross phase.

Further, the operating time of the relay is not constant due to the type of the relay, aging, etc., so it is necessary to detect all phases of the relay.

However, in the conventional configuration, since the relay contact operating means 4 is constantly operated to detect the open / closed state of the relay contact 6, other input / output and sequences other than relay control are ignored. However, it is difficult to perform control of other devices and control of relays in parallel with a microcomputer having a small processing capacity.

The present invention has been made in view of the above problems, and an object of the present invention is to enable operation control of a relay together with other input / output or sequence control.

Means for Solving the Problems In order to achieve the above object, the present invention provides a phase detection unit that detects a phase of an AC power supply, a relay contact that controls supply of the AC power supply to a load, and an operation of the relay contact. Relay contact operating means to control and ON / OFF of the relay contact
A relay contact detection means for detecting at a specific phase of the AC power supply,
After the ON / OFF drive, the operation time measuring means for measuring the time until the relay contact ON / OFF is detected by the relay contact detecting means, and the ON / OFF of the relay contact is specified by the output of the operation time measuring means. The relay contact correction means for correcting the ON / OFF drive timing of the relay contact and the ON / OFF detection of the relay contact by the output of the relay contact correction means are detected at the specific phase so that the phase can be detected. A relay contact correction end storage means for storing the information, and the relay contact correction means changes the correction content according to the output of the relay contact correction end storage means.

Action With this configuration, in order to detect the open / closed state of the relay contact, it is not necessary to constantly detect the relay contact operation, and a microcomputer with low processing capacity can effectively control the relay contact in parallel with other loads. It becomes possible to do. In other words, by detecting ON / OFF detection of the relay contact in synchronization with a predetermined phase of the AC power supply, deterioration of the relay contact due to arc sparks, etc. is effectively prevented, while other loads are independent of the relay operation. Moreover, it can be controlled by an inexpensive microcomputer. Further, the relay contact correction end storage means corrects the correction content of the relay contact correction means only when the operation of the relay changes in a predetermined half-wave of the AC power supply, so that the relay contact detection means is inexpensive. Despite the configuration, it is possible to effectively detect the operation time of the relay within the half wave.

EXAMPLES Examples of the present invention will be described below with reference to FIGS. 1 to 5. FIG. 1 shows a block diagram of the relay control device of the present invention. In particular, the relay contact correction end storage means 18 has an appropriate phase of the AC power supply even if the relay contact 6 is once (generation of arc sparks at the relay contact). When the relay contact detecting means 5 detects that the relay contact 6 is actually turned on / off at a phase at which the relay contact 6 can be effectively prevented, for example, the <a> phase of the AC power source 1). It is something to remember. 2 shows an embodiment of the relay contact detecting means used in the present invention. The waveform of each part obtained by this circuit configuration is shown in FIG. 3 according to the open / close state of the relay contact 6. It is shown.

The operation of the above configuration will be described. The relay contact 6
However, when it is open, the current flows only in one direction through the load 12, the resistor 13 and the diode 15, so that the AC waveform a is input in only one direction as shown in section A of FIG. 3d. A signal is generated. On the other hand, when the relay contact 6 is closed,
No alternating current will flow through the diode 15
The divided voltage by 13 and the resistor 14 is generated as an input signal to the microcomputer 16 or the like. There is a slight time lag between the time when the drive signal is applied to the relay coil 3 and the time when the relay contact 6 actually operates, as shown in b and c of FIG. Attention must be paid to the timing of driving of No. 3. In addition, when the relay contact 6 is opened and closed, there is a high possibility that sparks or the like will occur due to the electrical characteristics, and the size of the spark will greatly affect the life of the relay contact 6. Further, noise given to other circuit configurations is also proportional to the size of the spark, and it is desired to open / close the relay contact 6 in a phase in which the spark is less likely to fly. From the past data, the spark is larger when the relay contact 6 is opened than when the relay contact 6 is closed, and the phase around <b> in FIG. 1 is the largest, and the closer the phase is to <a>, It has been confirmed that the spark gradually becomes smaller, and only a very slight spark is emitted at phase <a>. Therefore, a method for realizing the opening / closing operation of the relay contact 6 by using the circuit diagram of FIG. 2 so as to perform the opening and closing operation of <a> of FIG. 1 is specifically shown in the flowchart of FIG. , Here, when the relay contact 6 operates in a specific phase, the correction content for the opening / closing operation of the relay contact 6 can be changed when the relay contact 6 is opened or closed. The time from when the drive control is applied to when the relay contact 6 is actually operated is substantially constant for each relay, and therefore the correction work of the relay contact 6 is possible.

Next, the contents of the flowchart of FIG. 4 will be described. First, when the power of this system is turned on and the system is ready for work, the operating time of the relay is unknown, so an appropriate operating time is initially set.

Next, when actually operating the relay coil 3 to operate the relay contact 6, different input signals such as the section A and the section B are applied to the input terminals of the microcomputer as shown in FIG. It will be a thing. Here, when the opening / closing operation of the relay contact 6 is performed between i = 6 and i = 12 in FIG. 5, the input signal is switched from the low level to the high level depending on the state of the relay contact 6. , The operation of the relay contact can be detected effectively, but if it is done between i = 0 to i = 6, the input signal is
Since it is at the high level (see b and c in FIG. 5), an accurate operating phase cannot be detected. Therefore, if the opening / closing operation of the relay contact 6 is not detected in the phase of i = 6 to i = 12 in FIG. 5 even once, the phase for generating the output signal to the drive of the relay coil 3 is shifted by 180 °. The possibility that the next contact opening / closing operation will be performed between i = 6 and i = 12 is high. Then, when it is carried out between i = 6 and i = 12, when the ideal relay contact operation phase is i = 11, the phase difference from i = 11 becomes the phase of the next relay coil 3 drive. I will give you feedback. Also, even once
The opening / closing operation of the relay contact 6 is an ideal phase (for example, i = 11)
If the relay contact 6 is opened / closed between i = 0 and i = after that, the operation time of the relay depends on each relay as described above.
Since it is almost constant, when the drive of the relay coil 3 is controlled aiming at i = 11, it is highly possible that the relay contact 6 is operating in the range of i = 12 to i = 1. To modify the phase, stop the 180 ° phase width and apply a slight phase width.

In addition, when the relay contact 6 is opened and closed,
Since the operating time of the relay is different,
The correction value is changed.

EFFECTS OF THE INVENTION As is clear from the above examples, according to the present invention,
Realized a relay contact detection circuit with a cheaper configuration than before,
Moreover, since it is not necessary to constantly detect the relay contact, it is possible to sufficiently execute other control even in a microcomputer having a small number of output ports. Further, the relay contact correction end storage means corrects the correction content of the relay contact correction means only when the operation of the relay changes in a predetermined half-wave of the AC power supply, so that the relay contact detection means is inexpensive. Despite the configuration, it is possible to effectively detect the operation time of the relay within the half wave.

[Brief description of drawings]

FIG. 1 is a block diagram of a relay control device showing an embodiment of the present invention, FIG. 2 is a circuit diagram of a detection circuit of the relay contact, FIG. 3 is a timing diagram showing waveforms of respective parts of FIG. FIG. 4 is a flowchart showing the same control, FIG. 5 is a diagram showing voltage waveforms according to the state of the relay contacts, FIG. 6 is a block diagram showing a relay control device of a conventional example, and FIG. 7 is the relay contact detection. FIG. 8 is a circuit diagram of the circuit, FIG. 8 is a waveform diagram of each part of the circuit shown in FIG. 7, FIG. 9 is a timing diagram showing a partial voltage waveform of the circuit of FIG. 7, and FIG. It is a figure explaining the state of an arc spark. 1 ... AC power supply, 2 ... Load, 3 ... Relay coil, 4
...... Relay contact operation means, 5 …… Relay contact detection means,
6 ... relay contact, 7 ... operating time measuring means, 8 ... relay contact correcting means, 16 ... signal input device such as microcomputer,
18: Relay contact correction completion storage means.

Claims (1)

[Claims] 1. A phase detection means for detecting the phase of an AC power supply, a relay contact for controlling the supply of the AC power supply to a load, a relay contact operation means for controlling the operation of the relay contact, and a relay contact for the relay contact. Relay contact detection means for detecting ON / OFF at a specific phase of the AC power supply, and after ON / OFF drive of the relay contact by the relay contact operation means, until ON / OFF detection of the relay contact by the relay contact detection means And a relay that corrects the ON / OFF drive timing of the relay contact so that ON / OFF of the relay contact can be detected at a specific phase by the output of the operation time measuring means. A contact correction means and a relay contact correction end storage means for storing that ON / OFF detection of the relay contact by the output of the relay contact correction means is detected at the specific phase, Serial relay contacts correction means control relays made by changing the correction contents in accordance with the output of the relay contact correction end storage means.