JP2517061B2 - Relay control device - Google Patents

Description

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

2. Description of the Related Art Conventionally, this type of relay control device is provided with a relay contact that energizes an AC power supply when a load is applied, and this relay contact is driven by a relay coil. I was measuring the time until it worked. Here, the operation time of the relay is measured as described above.When the relay contact is turned ON / OFF, depending on the operating point with respect to the phase of the AC power supply, arc sparks may easily occur at the relay contact. The operation time of the relay was measured in order to specify the operation point of the relay coil so that the relay contact could be turned ON / OFF at a specific phase of the power supply.

Problems to be Solved by the Invention In such a conventional configuration, since the relay operating time is different every time due to variations in the relay, variations in parts, or changes over time, the ON / OFF point of the relay contact is always detected. Had to be. Therefore, in order to allow loads other than the relay to proceed at the same time as measuring the operation time of the relay, a microcomputer capable of parallel processing was required.

In view of the above problems, the present invention provides a relay control device capable of controlling operation of a relay that effectively suppresses deterioration of relay contacts with a configuration using an inexpensive computer, and simultaneously performing input / output control of other loads and switches. The purpose is to obtain.

Means for Solving the Problems In order to achieve the above object, the present invention provides 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, and an operation of this relay contact. Relay contact drive means for control, input / output control means for processing input / output other than relays, relay contact detection means for detecting ON / OFF of relay contacts, and relay contact ON / OFF by relay contact drive means After the drive, the operation time measuring means that measures the time until the relay contact ON / OFF is detected by the relay contact detecting means, and the ON / OFF of the relay contact can be detected at a specific phase by the output of this operation time measuring means. A relay contact correction means for correcting the ON / OFF drive timing of the relay contact is provided, and the input / output processing other than the relay by the input / output control means, the relay contact drive means, and the relay contact detection Knowing means, the operating time measuring means, ON / OFF drive processing of the relay contact consisting of the relay contact correcting means is performed in synchronization with a specific phase of the AC power source detected by the phase detecting means, and After the completion of the processing by the entry output control means, it is changed so that it is always detected regardless of the specific phase of the AC power supply.

This configuration does not need to constantly detect the relay contact operation in order to detect the open / closed state of the relay contact, and an inexpensive microcomputer, etc. with a small processing capacity can effectively operate the relay contact in parallel with other loads. It becomes possible to control. That is, the ON / OFF of the relay contact is synchronized with the predetermined phase of the AC power supply, by driving or detecting,
While effectively preventing deterioration of the relay contact due to arc sparks, other loads can be controlled by an inexpensive microcomputer regardless of the operation of the relay. Further, by always detecting the operation of the relay except for the processing time for controlling the input / output other than the relay, it is possible to obtain a control device for the relay that is resistant to noise.

Embodiments Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. Reference numeral 1 is a measuring means for constantly counting the elapsed time, and 2 is a signal output means for outputting a signal when the elapsed time of the measuring means 1 exceeds a certain time. Reference numeral 3 is a load to which the AC power supply 4 is energized via the relay contact 5.
Here, the drive of the relay contact 5 is realized by the relay contact drive means 6, and the open / close state of the relay contact 5 is performed by the relay contact detection means 7. Further, the operation time from the actuation of the relay contact 5 to the change of the open / closed state of the relay contact 5 is measured by the operation time measuring means 8, and 9 also indicates the operation time measured by the operation time measuring means. In addition, it is a relay contact correction means for feeding back the operating point of the relay contact 5 so as to be performed at a specific phase of the AC power supply 4. Reference numeral 10 is a synchronizing means for controlling the drive, detection and operation time of the relay contact 5. Reference numeral 1 is an input / output control means for performing input / output processing other than relays such as switches, LEDs and motors, and 14 is a phase detection means for detecting a phase such as zero cross of the AC power supply 4. Will be corrected.

FIG. 2 is a circuit diagram showing a specific configuration of the present invention. Reference numeral 11 denotes a matrix that controls the input / output loads of A1 to A12 by combining the output ports P01 to P03 and the input ports P11 to P14. P21 is an input port for detecting the open / closed state of the relay contact 5. P31 is an output port for driving the relay contact 5. 12 is a microcomputer that operates the entire system including control of each input / output.

The operation of the relay control device according to the present embodiment configured as described above will be described below.

In order to control the inputs and outputs A1 to A12 of each matrix respectively, the output of output ports P01 to P03 and the input ports P11 to P14
It becomes possible to control by combining the input and output of. Specifically, for example, when operating the load of A1, P01
And P11 should work at the same time. By the way, the outputs A1 to A12 of each matrix are thus P11 to P01 to P03.
Since it is controlled in order by the output of ~ P14, P01 ~ P0
When only specific terminals in 3 can be driven, only the loads connected to specific terminals in P01 to P03 can be controlled among matrix outputs A1 to A12, and all loads can be controlled. Disappear. To avoid such inconvenience, P0
It is necessary that 1 to P03 are always output in order at a fixed cycle.

On the other hand, in order to prevent the relay contact 5 from deteriorating, it is desirable that the relay be controlled so that the opening / closing operation is performed at a specific voltage phase of the AC power supply. For that purpose, from the drive output port P31 of the relay to the relay contact. After the signal of the opening / closing operation of 5 is output, the operation time until the input port P21 detects that the relay contact 5 is actually opened / closed is measured, and the value is fed back at the next relay contact drive output. There is a need to. There are several methods to measure the time until the relay contact 5 actually operates after the drive output of the relay contact 5 is performed. However, if you have a timer for measuring the operation time separately from the microcomputer 12. Although it is possible to use the data of the timer, it is often difficult to use the dedicated timer because the cost needs to be reduced and the microcomputer 12 itself needs to have the timer function. At this time, if the microcomputer 12 is made to perform the timer function operation, depending on the performance of the microcomputer, it is often only possible to perform the timer function work.In that case, the matrix outputs A1 to A12 are input during the timer function operation. It becomes impossible to control the output.

Therefore, as shown in FIG. 3, assuming that the AC power supply is a, the relay contacts are driven and the open / closed state is detected in accordance with the output timings of the time division timings b to d for outputting the matrix outputs A1 to A12. By doing so, it becomes possible to have a timer function at the same time.

Specifically, the relay contact 5 is time-divided (b to d in FIG. 3).
Timing of rising) (eg 1 in FIG. 3)
It is driven according to 3), and the time when the relay contact 5 actually operates is detected at the time-divisional time point as described above. That is, since the detection system of the operation time of the relay can be detected in synchronization with the sampling of the AC power supply 4 divided into three, the accuracy thereof is lower than that in the case of always detecting the operation of the relay, but the relay contact 5 Judging from the viewpoint of preventing the deterioration of the relay contact 5 due to the prevention of the arc spark, the sufficient effect can be obtained. That is, when the load controlled by the relay contact 5 is resistive, the relay contact 5
Is known to cause a large arc spark when it is turned on / off between the time when the zero cross point of the AC power supply 4 is slightly exceeded and the peak time of the AC voltage, and within three divisions before the zero cross time of the AC power supply. ON / OFF of the relay contact at
By doing so, it becomes possible to effectively prevent the deterioration of the relay contact 5. As a method to improve this detection accuracy,
As shown in e of FIG. 3, the number of divisions may be doubled, for example, to operate or detect at the rising edge of each division point. At this time, the outputs of matrix outputs A1 to A12 are
By processing the two divisions shown in FIG. 3e as the division width of one matrix, the time division control of the input and output of the matrix is executed, and at the same time, the measurement accuracy of the operating time of the relay contact 5 is improved. It is possible to improve.

Further, when inputting the open / closed state of the relay contact 5 at the time of rising of each time division, it is necessary to perform more stable detection in order to strengthen against noise and the like.

Therefore, as shown in FIG. 4, the operation of the relay contact 5 is controlled so far in synchronization with each time division time point a (corresponding to the rising time point of the waveforms b to d in FIG. 3). However, after the input / output processing of the matrix other than the relay-related processing is completed (other than the shaded area in Fig. 4b), the relay contacts can be turned ON / OFF even if they are no longer synchronized with the division time point a.
Can be detected at all times, so the detection accuracy of the relay can be improved. That is, the shaded area in FIG. 4b processes, for example, an input signal of matrix input / output,
Processing such as determining the next output signal is performed, but it is possible to reliably detect ON / OFF of the relay contact even if it is not synchronized with the division time a except for the shaded area in Fig. 4b. Moreover, it is possible to operate within the width of three divisions before the zero cross point of the AC power supply. Specifically, in the case of detecting in synchronization with each division time point a, at each time division time point a due to the influence of noise or the like, if the signal related to the relay contact happens to be unstable at the time point of the next division time point, Since the signal related to the relay contact is judged as the definite value for the first time, the operation time of the relay is erroneously judged to be long by three divisions.
It is possible to prevent such erroneous judgments and realize a relay control device that is resistant to noise and the like by constantly detecting ON / OFF of the relay contacts without synchronizing with the division time point a except for the shaded area in FIG. It will be possible.

EFFECTS OF THE INVENTION As is clear from the above embodiments, according to the present invention, the detection signal can be fetched if the relays are operated in synchronization during the period when various control processes are not performed, so the operating time of the relay contacts is measured. It is possible to open and close the relay contacts at a specific voltage phase of the AC power supply in microcomputer control that performs time-division control, and prevent deterioration of the relay contacts due to the opening and closing operations of the relay contacts. An effect that the life can be extended can be obtained.

[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 thereof, and FIGS. 3 and 4 are timing diagrams showing a state of simultaneous division. 1 ... Measuring means, 2 ... Signal output means, 3 ... Load, 4
...... AC power supply, 5 ...... Relay contact, 6 ...... Relay contact driving means, 7 ...... Relay contact detecting means, 8 ...... Operating time measuring means, 9 ...... Relay contact correcting means, 10 ...... Synchronizing means.

Claims (1)

(57) [Claims] 1. A phase detection means for detecting a phase of an AC power supply, a relay contact for controlling supply of the AC power supply to a load,
A relay contact drive unit that controls the operation of this relay contact, an input / output control unit that processes input / output other than the relay, a relay contact detection unit that detects ON / OFF of the relay contact, and a relay by the relay contact drive unit. After the contact is turned ON / OFF, the operation time measuring unit that measures the time until ON / OFF detection of the relay contact by the relay contact detection unit and the output of this operation time measurement unit turns ON / OFF the relay contact in a specific phase. The relay contact correction means for correcting the ON / OFF drive timing of the relay contact so that the relay contact can be detected by the input / output control means other than the relay input / output processing, the relay contact drive means, the relay contact ON / OFF drive processing of the relay contact consisting of the detection means, the operation time measurement means, and the relay contact correction means is synchronized with the specific phase of the AC power source detected by the phase detection means. Together takes place Te, the operation completion by output control means, the control device of the relay to change to sense regardless constantly a specific phase of the AC power source.