CN110763991A - Relay life count measuring device - Google Patents

Abstract

A relay life counting and measuring device includes a controller unit, an action counting unit of L switch groups, a man-machine interface unit, and a relay driving unit. The man-machine interface unit is used to issue a detection command to display the life of the L relay switch groups; the controller unit sends a relay drive signal to the relay drive unit to control the actions of the L relay switch groups; the L switch group action counting units respectively The actions of each relay switch group are counted to obtain L action count values and sent to the controller unit. The device adopts the method of setting a plurality of counters outside the controller unit to count the number of actions of the relay switch group respectively, which can automatically filter out the edge jitter interference in the electrical pulses generated by the action of the relay switch group, and ensure the life detection of the relay. The accuracy of the relay switch group is not limited by the number of internal counters in the controller unit.

Description

Relay life count measuring device

The patent application of the present invention is a divisional application, the original application number is 201711133940.8, the application date is November 16, 2017, and the name of the invention is the relay life count measurement method.

technical field

The invention relates to the field of testing methods and devices, in particular to a relay life count measuring device.

Background technique

The life of the relay is generally tens of thousands to hundreds of thousands of times. Simulate the use conditions of the relay, by controlling the action of the relay to make the switch on and off to generate electric pulses, and then counting the electric pulses, the life of the relay can be tested. The electrical pulses generated by the relay action contain edge jitter, and directly counting the unprocessed pulses will cause great errors. Use the MCU software delay method to remove the influence of the jitter pulse. When the MCU needs to perform life testing on multiple relays at the same time, the MCU software delay method will make the MCU unable to do what it wants.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the life measurement of the existing relays, the present invention provides a relay life counting and measuring device. The device includes a controller unit, an action counting unit of L switch groups, a man-machine interface unit, and a relay driving unit.

The man-machine interface unit is electrically connected to the controller unit for issuing detection commands and displaying the lifespan of the L relay switch groups; the controller unit is electrically connected to the relay driving unit, and sends a relay driving signal to the relay driving unit to control the L relay switch groups. Actions of the relay switch groups; the L switch group action counting units respectively count the actions of the L relay switch groups to obtain L action count values; the switch group action counting units are electrically connected to the controller unit for the controller units to separate Read in the action count values of the L switch group action count units and control the clearing of the action count values of the L switch group action count units.

The switch group action counting unit is electrically connected to the controller unit, and the method for the controller unit to read in the action count values of the L switch group action count units respectively is that the action count values of the L switch group action count units are all three. The output ports of all switch group action counting units are all connected in parallel to the count data input port of the controller unit; the controller unit sends a gating control signal to enable the tri-state buffering of each switch group action counting unit one by one The output port reads the corresponding action count value from the count data input port.

The relay life counting and measuring device further comprises a gating control unit; the controller unit sends a switch group action counting unit address coding signal to the gating control unit, and the gating control unit decodes the switch group action counting unit address coding signal, Get the gating control signal.

The L switch group action counting units all include a pulse generating circuit, an RS flip-flop and a tri-state output counting circuit with the same structure and composition. The pulse generating circuit outputs the first initial pulse and the second initial pulse generated by the action of the relay switch group; the RS trigger converts the input first initial pulse and the second initial pulse into the counting pulse after filtering out the edge jitter interference pulse; The three-state output counting circuit counts the counting pulses and outputs the action count value.

The relay switch group is composed of the relay normally open switch and the relay normally closed switch in the same relay; the level change of the first initial pulse is consistent with the action change of the normally open switch in the relay switch group, and the level change of the second initial pulse is the same as that of the relay switch group. The action changes of the normally closed switches in the relay switch group are consistent; when the normally open switches and normally closed switches in the relay switch group are all disconnected, the state of the first initial pulse and the second initial pulse output by the pulse generating circuit are both RS triggers The invalid signal input status of .

The steps of the relay life count measurement device for performing the relay life count measurement include:

Step 1, initialization, including setting the detection flags of the L relay switch groups to the detection state, clearing the life counter to 0, and sending a clear signal to clear all the L action count values to 0;

Step 2, controlling the L relay switch groups to act once, and simultaneously counting the number of actions of the L relay switch groups to obtain L action count values; the life counter is incremented by 1;

Step 3, read the count value of the current L actions;

Step 4, one by one, judge whether the relay switch group whose detection mark is in the state of inspection is invalid; set the detection mark of the relay switch group that is judged to be invalid this time to the state of stop inspection, and at the same time use the count value of the current life counter as this time. It is judged as the life value of the failure relay switch group;

Step 5, if the detection flags of the L relay switch groups are still in the detection state, return to Step 2, otherwise stop detection.

The method is to judge whether the relay switch group whose detection flag is in the state of inspection is invalid. The method is that the error between the number of times the relay switch group is controlled to be turned on and off and its action count value is less than E, then the relay switch group is not invalid, otherwise Invalid; the M is the maximum count value of the action count value, and the E is an integer greater than or equal to 1 and less than or equal to M/2. The judgment method that the error between the number of times the relay to be judged is controlled on and off and its action count value is less than E is to take the count value of the current life counter to M to obtain the remainder Q; If the action count value is K, the relay to be judged is controlled when it satisfies |K-Q|<E, or |K-(Q-M)|<E, or |K-(Q+M)|<E The error between the number of on and off and its action count value is less than E.

Judging whether the relay switch group whose detection flag is in the state of inspection is invalid, the method is either, when the count value of the current action of the relay switch group to be judged is not in the relationship of incrementing the count value of the previous action, then the relay switch group is invalid. , otherwise it does not fail; method or is, when it is to be judged that the count value of the current action of the relay switch group for S consecutive times and the count value of the previous action are not in the relationship of increasing by 1, then the relay switch group is invalid, otherwise it is not invalid; the S is Integer greater than or equal to 2.

Judging whether the relay switch group whose detection flag is in the state of inspection is invalid, the method is alternatively, when it is to be judged that the current operation count value of the accumulated W times of the relay switch group and the previous operation count value are not in the relationship of increasing by 1, then the relay The switch group fails, otherwise it does not fail; the W is an integer greater than or equal to 2.

The beneficial effects of the invention are: the relay life measurement is carried out in the form of a switch group composed of normally open switches and normally closed switches in the same relay, and the service life of multiple relay switch groups in multiple relays can be detected at the same time; using RS The trigger automatically filters out the edge jitter interference in the electrical pulse generated by the action of the relay switch group, which ensures the accuracy of the relay life detection; multiple counters are set outside the controller unit to count the number of actions of the relay switch group respectively. In this way, the number of relay switch groups that can detect the relay life at the same time is not limited by the number of counters inside the controller unit.

Description of drawings

1 is a block diagram of an embodiment of a relay life count measuring device when L=4;

2 is an embodiment of a switch group action counting unit;

Fig. 3 is 1# pulse generation circuit embodiment;

Fig. 4 is an RS trigger embodiment;

5 is an embodiment of a three-state output counting circuit;

FIG. 6 is an embodiment of a relay driving unit.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings. The relay life counting and measuring device includes a controller unit, an action counting unit of L switch groups, a man-machine interface unit, and a relay driving unit. The man-machine interface unit is electrically connected to the controller unit for issuing detection commands and displaying the lifespan of the L relay switch groups; the controller unit is electrically connected to the relay driving unit, and sends a relay driving signal to the relay driving unit to control the L relay switch groups. The action of the relay switch group; the L switch group action counting units respectively count the action times of the L relays to obtain L action count values; the switch group action counting unit is electrically connected to the controller unit, and the controller unit reads L respectively. The action count value of each switch group action count unit. When the L value is large, the action count values of the L switch group action count units are output in tri-state buffer mode; the tri-state buffer output ports of all switch group action count units are all connected in parallel to the count data input port of the controller unit; The controller unit sends a gating control signal to enable the three-state buffer output ports of the action counting units of each switch group one by one, and reads the corresponding action count value from the counting data input port; the controller unit sends a clear signal to make L switch groups The action count value of the action count unit is cleared to 0. The relay life count measuring device may also include a gating control unit electrically connected to the controller unit; the controller unit sends a switch group action counting unit address coding signal to the gating control unit, and the gating control unit acts on the switch group. The counting unit address coding signal is decoded to obtain a gating control signal, which enables the tri-state buffer output port of the switch group action counting unit corresponding to the switch bank action counting unit address coding signal. 1 relay switch group refers to a switch group consisting of 1 relay normally open switch and 1 relay normally closed switch in the same relay; L relay switch groups can all be in the same relay, or can be separately in the same relay. In several relays, the number of relay switch groups in each relay may be the same or different.

Fig. 1 is a block diagram of an embodiment of a relay life counting measuring device when L=4, including a controller unit 10, 1# switch group action counting unit 11, 2# switch group action counting unit 12, 3# switch group action counting unit 13, 4 #The switch group action counting unit 14, the man-machine interface unit 15, the gating control unit 16, and the relay drive unit 17 can simultaneously measure the life of four relay switch groups.

The man-machine interface unit 15 communicates with the controller unit 10 through the interface I/O1 of the controller unit 10, and is used for the issuance of detection commands, parameter modification and display of the life of each relay switch group; The relay drive unit 17 sends a relay drive signal to control the actions of the 1# to 4# relay switch groups; 1# switch group action counting unit 11, 2# switch group action counting unit 12, 3# switch group action counting unit 13, 4# The switch group action counting unit 14 respectively performs electrical pulse generation, filtering and counting the number of actions for the 4 relay switch groups; the controller unit 10 sends the address code of the switch group action counting unit to be gated to the gating control unit 16 through the output port OUT1 signal, the gating control unit 16 decodes the address coding signal of the switch group action counting unit, and obtains the gating control signals CS1, CS2, CS3, CS4, and controls the 1# switch group action counting unit 11 and the 2# switch group action count respectively. Unit 12, 3# switch group action count unit 13, 4# switch group action count unit The action count values CV1, CV2, CV3, CV4 of the switch group action count unit are sent to the controller unit 10 through the input port IN1, and IN1 is the count data input of the controller unit Port; controller unit 10 sends a clear signal to 1# switch group action counting unit 11, 2# switch group action counting unit 12, 3# switch group action counting unit 13, 4# switch group action counting unit 14 through output port OUT3 CLR; When the clear signal CLR is valid, the action count values of the 4 switch group action count units are all cleared to 0.

Figure 2 is a block diagram of an embodiment of the 1# switch group action counting unit. In FIG. 2, the 1# pulse generation circuit 100 outputs the first initial pulse P11 and the second initial pulse P12 generated by the action of the 1# relay switch group; the RS flip-flop 101 will input the first initial pulse P11 and the second initial pulse P11 and the second initial pulse P12 is converted into the counting pulse P13 after filtering out the edge jitter interference pulse; the three-state output counting circuit 102 counts the counting pulse P13, controlled by the gating control signal CS1, and outputs the action count value CV1 of the 1# relay switch group; three The three-state output counting circuit 102 is also controlled by the clear-to-zero signal CLR. When the clear-to-zero signal CLR is valid, the action count value in the three-state output count circuit 103 is cleared to zero.

FIG. 3 is an embodiment of a 1# pulse generating circuit. 1# Relay switch group includes normally open switch KA1-1 and normally closed switch KA1-2; KA1-1 is connected in series with load resistor R11, and then connected in parallel to DC power supply +VCC1 and common ground GND; resistor R13 and resistor R14 form a voltage divider The circuit divides the voltage on the load resistor R11, and outputs the first initial pulse P11 generated by the opening and closing of the normally open switch KA1-1 in the 1# relay switch group; the diode VD1 acts as a unidirectional conduction protection, and the diode TVS1 acts as a limit Amplitude and reverse protection. After KA1-2 is connected in series with the load resistor R12, it is connected in parallel to the power supply +VCC1 and the common ground GND; the resistor R13 and the resistor R14 form a voltage divider circuit to divide the voltage on the load resistor R12, and the output is connected to the 1# relay switch group. Close the second initial pulse P12 generated by the on-off of the switch KA1-2; the diode VD2 plays the role of unidirectional conduction protection, and the diode TVS2 plays the role of limiting and reverse protection. Diodes TVS1 and TVS2 select Zener diodes or TVS tubes. By changing the size of the load resistors R11 and R12, the magnitude of the resistive DC load current of the normally open switch KA1-1 and normally closed switch KA1-2 in the relay switch group to be detected can be adjusted. The voltage dividing ratio of the two voltage dividing circuits needs to be comprehensively considered according to the size of the power supply + VCC1 and the allowable high level and low level ranges of P11 and P12.

When the load of the relay switch group to be detected needs to be powered by an AC power supply, in the embodiment of the 1# pulse generation circuit shown in FIG. 3, the DC power supply +VCC1 and GND can be replaced by the AC power supply AC1 and AC2. When the potential of AC1 is higher than that of AC2 is a positive half wave. When the normally open switch KA1-1 is turned on, the first initial pulse P11 outputs a pulse wave with a period of 20ms and a duty cycle of less than 50%; when the normally open switch KA1-1 is turned off, the first initial pulse P11 outputs Low level; when the normally closed switch KA1-2 is turned on, the second initial pulse P12 outputs a pulse wave with a period of 20ms and a duty cycle of less than 50%; when the normally closed switch KA1-2 is turned off, the second The initial pulse P12 outputs a low level; when the 1# relay switch group performs the action to switch the switch state, the beginning and end of the pulse wave with a period of 20ms and a duty cycle of less than 50% may generate jitter pulses with variable width and interval. Similarly, by changing the size of the load resistors R11 and R12, the magnitude of the resistive AC load current of the normally open switch KA1-1 and the normally closed switch KA1-2 in the relay switch group to be detected can be adjusted. The voltage dividing ratio of the two voltage dividing circuits needs to be comprehensively considered according to the peak value of AC1 and AC2 of the AC power supply, as well as the allowable high level and low level ranges of P11 and P12. The load resistors R11 and R12 can also be changed to inductive loads or capacitive loads.

FIG. 4 is an embodiment of an RS flip-flop. In FIG. 4 , the NOR gates FO1 and FO2 form an RS flip-flop, the first initial pulse P11 is the set signal of the RS flip-flop, and the second initial pulse P12 is the reset signal of the RS flip-flop, both of which are active high. When the normally open switch KA1-1 in the 1# relay switch group is disconnected and the normally closed switch KA1-2 is closed, P11 is low level, and the high level or positive pulse of P12 will set the count pulse P13 output from FO2 to 0; When the normally open switch KA1-1 in the 1# relay switch group is closed and the normally closed switch KA1-2 is disconnected, P12 is low level, and the high level or positive pulse of P11 will set the counting pulse P13 to 1; in the relay switch group When the normally open switch and normally closed switch are in action, they are both broken first and then closed. In the process of the 1# relay switch group being electrified or de-energized in its relay coil, the normally open switch KA1-1 and the normally closed switch KA1 -2 is in the state of all disconnection for a short time, at this time, P11 and P12 are both low level, and the state of count pulse P13 is maintained; when the normally open switch is turned from OFF to ON, the normally closed switch has been disconnected and reset The signal is invalid, even if there is a jitter pulse when the normally open switch is turned from off to on, the jitter pulse is also a valid set signal, and P13 is set to 1; similarly, when the normally closed switch is turned from off to on, The normally open switch has been turned off, and the set signal is invalid. Even if there is a jitter pulse when the normally closed switch is turned from off to on, the jitter pulse is a valid reset signal, and P13 is set to 0. In FIG. 4, the output terminal of the NOR gate FO2 is the non-inverting output terminal of the RS flip-flop; the count pulse P13 can also be output from the inverting output terminal of the RS flip-flop, that is, the output terminal of the NOR gate FO1.

The RS flip-flops can also use other forms of RS flip-flops other than those shown in FIG. 4 , and the pulse generating circuit can also use other forms of circuits other than those shown in FIG. 3 . Since the first initial pulse and the second initial pulse output by the pulse generating circuit are used as the input signals of the RS flip-flop, the RS flip-flop does not allow the input set signal and reset signal to be valid at the same time. Therefore, the pulse generating circuit generates the first initial pulse, The principle of the second initial pulse is: when the normally open switch and normally closed switch of the relay switch group are all disconnected during the process of electrification or power loss of the relay coil, the first initial pulse, the second initial pulse output by the pulse generation circuit The states of the two initial pulses are both the invalid signal input states of the RS flip-flop. For example, when the set signal and reset signal input by the RS flip-flop are both active at high level, when the normally open switches and normally closed switches in the relay switch group are all disconnected, the first initial pulse and the second initial pulse are both Low level; when both the set signal and reset signal input by the RS trigger are active at low level, when the normally open switches and normally closed switches in the relay switch group are all disconnected, the first initial pulse, the second initial pulse are high level.

FIG. 5 is an embodiment of a three-state output counting circuit. Figure 5(a) is the first embodiment of the three-state output counting circuit, which is composed of a counter FC1 and a non-gate FN1, and FC1 is an 8-bit binary counter 74HC590 with a three-state output. FC1's counting enable terminal CCKEN inputs 0, and the clearing control terminal CCLR is the input terminal of the clearing signal CLR of the tri-state output counting circuit; the clearing signal CLR is active at low level, that is, the clearing signal CLR output by the controller unit is low power Usually, the action count value in the counter FC1 is cleared to 0; when the clear signal CLR output by the controller unit is at a high level, FC1 works in the counting state, and the counting pulse P13 is directly connected to the counting pulse input terminal CCK of FC1, and FC1 is in the counting state. The rising edge of the count pulse P13 is counted up by 1 to obtain the action count value. The count pulse P13 is connected to the data latch terminal RCK of FC1 through the NOT gate FN1, and the content of the internal counter of FC1 is latched to the output latch at the falling edge of the count pulse P13. The strobe control signal CS1 is connected to the output enable control terminal G of FC1. When CS1 is low, FC1 outputs the action count value CV1 in the output latch from Q7-Q0; when CS1 is high, Q7- of FC1 Q0 is in a high-impedance state. The action count value output by the three-state output counting circuit Embodiment 1 is an 8-bit binary count value.

Figure 5(b) shows the second embodiment of the tri-state output counting circuit, which is composed of a counter FC2 and a tri-state buffer FB1, FC2 is a 4-bit binary counter 74HC161, and FB1 is a tri-state buffer 74HC244. The counting control terminals CTP and CTR of FC2, and the number setting control terminal LD are connected to 1, and the clearing control terminal CR is the input terminal of the clearing signal CLR of the three-state output counting circuit; the clearing signal CLR is active at low level, that is, the control When the clearing signal CLR output by the controller unit is low level, the action count value in the counter FC2 is cleared to 0; when the clearing signal CLR outputted by the controller unit is high level, FC2 works in the counting state, and the counting pulse P13 is directly connected To the count pulse input terminal CP of FC2, FC2 adds 1 count on the rising edge of count pulse P13 to obtain the action count value. The 4-bit data input terminals A3-A0 of the tri-state buffer FB1 are respectively connected to the 4-bit count value output terminals Q3-Q0 of the counter FC2, the gating control signal CS1 is connected to the output enable control terminal 1G of FB1, and CS1 is low power Usually, FB1 outputs the action count value CV1 output by the counter FC2 from Y3-Y0; when CS1 is at a high level, Y3-Y0 of FB1 is in a high-impedance state. The action count value output by Embodiment 2 of the three-state output counting circuit is a 4-bit binary count value.

In the embodiment of the relay life counting measuring device when L=4, the 2# switch group action counting unit, the 3# switch group action counting unit and the 4# switch group action counting unit use the same circuit composition as the 1# switch group action counting unit and Structure, that is, all switch group action counting units include pulse generating circuit, RS flip-flop and tri-state output counting circuit; all pulse generating circuits, RS trigger and tri-state output counting circuit have the same composition and structure.

FIG. 6 is an embodiment of a relay driving unit. Figure 6(a) is an embodiment when the relay coil is powered by a DC power supply, which is composed of a triode VT, a freewheeling diode VD, and a base resistor R61; the coil of the relay to be detected is connected in parallel to nodes A1 and A2, and the DC power supply of the relay coil The power supply is +V. Assuming that the four relay switch groups in the embodiment of FIG. 1 are included in two relays, in FIG. 6( a ), only two relay coils J1 and J2 are connected in parallel. When the relay drive signal C1 sent by the controller unit is at a high level, all the relay coils connected in parallel to nodes A1 and A2 are energized; when the relay drive signal C1 sent by the controller unit is at a low level, the parallel connection between nodes A1 and A2 All relay coils on the switch are de-energized; the relay drive signal C1 sent by the controller unit changes for one pulse period, and the relay switch group in all the relays on the nodes A1 and A2 in parallel with the coils acts once. When the number of relay coils is large and the triode VT in Fig. 6(a) is not enough to drive all of them, the same or similar drive circuit can be added to expand the drive capability.

Figure 6(b) is an embodiment when the relay coil is powered by an AC power supply, which consists of a current-driven solid-state relay SSR1, a varistor RU1, and a current limiting resistor R62; the coils of the relays to be detected are connected in parallel on nodes B1 and B2, and the relays The AC power supply of the coil is AC0; +VCC is the current drive power supply of SSR1. Assuming that the four relay switch groups in the embodiment of FIG. 1 are included in two relays, in FIG. 6(b), only two relay coils J3 and J4 are connected in parallel. When the relay drive signal C2 sent by the controller unit is at low level, all the relay coils connected in parallel on nodes B1 and B2 are energized; when the relay drive signal C2 sent by the controller unit is at high level, they are connected in parallel at nodes B1 and B2. All the relay coils on the node are de-energized; the relay drive signal C2 sent by the controller unit changes for one pulse period, and the relay switch groups in all the relays on the nodes B1 and B2 in parallel with the coils act once. When the number of relay coils is large and the solid state relay SSR1 in Figure 6(b) is not enough to drive all of them, the same or similar drive circuit can be added to expand the drive capability.

When there are relay coils powered by DC power supply and relay coils powered by AC power supply in the relay where the L relay switch groups are located, the circuits in Figure 6(a) and Figure 6(b) can be used to classify and drive at the same time. The relay drive unit can also use other circuits as required.

The human-machine interface unit preferably uses a touch screen, and uses RS485 or RS232 to communicate with the controller unit. The man-machine interface unit can also be composed of a key circuit and a liquid crystal display.

The action count values of all switch group action count units are output in tri-state buffer mode; the tri-state buffer output ports of all switch group action count units are all connected in parallel to the count data input port of the controller unit, and the controller unit sends a gating control signal The tri-state buffer output port of each switch group action counting unit is respectively enabled, and the action count value output by the enabled tri-state buffer output port is read from the count data input port. The action count value in Embodiment 1 of the tri-state output counting circuit is 8-bit binary data, and the tri-state buffer output port of the action counting unit of the switch group and the count data input port of the controller unit are both 8-bit parallel ports; the tri-state output count The action count value in the circuit embodiment 2 is 4-bit binary data, and the tri-state buffer output port of the switch group action count unit and the count data input port of the controller unit are both 4-bit parallel ports. When the L value is small and the number of digits of the action count value is small, the action count value of the action count unit of the switch group may not be output in the three-state buffer mode, but the action count value output ports of the action count unit of each switch group are directly connected respectively. To different parallel ports of the controller unit; for example, when L=4 and the action count value is a 4-bit binary value, directly connect the action count value output ports of the 4 switch group action count units to different parallel ports of the controller unit, It only needs to consume a total of 16-bit I/O lines of the controller unit, that is, 2 8-bit input ports.

The controller unit sends a gating control signal through the gating control unit. The gating control unit is a decoder circuit, which decodes the address coding signal of the switch group action counting unit sent by the controller unit to obtain the gating control signal. In the embodiment of FIG. 1, the address of the switch group action counting unit corresponding to the 1# switch group action counting unit 11, 2# switch group action counting unit 12, 3# switch group action counting unit 13, and 4# switch group action counting unit The encoded signals are binary 00, 01, 10, and 11, respectively, and the decoded output is CS1, CS2, CS3, CS4; the controller unit enables CS1, CS2, CS3, CS4 one by one, and enables the three-state operation of each switch group action counting unit Buffer the output port, and then read the corresponding action count value from the count data input port IN1. In the embodiment, the decoder circuit of the gating control unit may select 74HC139, or 74HC138, or be composed of gate circuits. When the L value is large, the decoder circuit can be composed of multiple pieces of 74HC139, or a multi-level cascade circuit composed of 74HC138, etc., or composed of multiple gate circuits. When the L value is small, the gating control unit can also be omitted, and the controller unit directly sends gating control signals to the action counting units of each switch group through the output port. For example, in the embodiment of FIG. 1 , the gating control signals CS1 and CS2 , CS3, CS4 can be directly issued by the controller unit 10, without using a gating control unit.

The controller unit is used to control the whole relay life counting and measuring device, so as to realize the counting measurement of the relay life. The controller unit is preferably composed of a single-chip microcomputer as the core, and the core of the controller unit can also be selected from ARM, DSP, or programmable logic controller. The count measurement of relay life consists of the following steps:

Step 1, initialization, including setting the detection flags of the L relay switch groups to the detection state, clearing the life counter to 0, and sending a clear signal to clear all the L action count values to 0;

Step 2, controlling the L relay switch groups to act once, and simultaneously counting the number of actions of the L relay switch groups to obtain L action count values; the life counter is incremented by 1;

Step 3, read the count value of the current L actions;

Step 4, one by one, judge whether the relay switch group whose detection mark is in the state of inspection is invalid; set the detection mark of the relay switch group that is judged to be invalid this time to the state of stop inspection, and at the same time use the count value of the current life counter as this time. It is judged as the life value of the failure relay switch group;

Step 5, if the detection flags of the L relay switch groups are still in the detection state, return to Step 2, otherwise stop detection.

Controlling the on-off of L relay switch groups means that the controller unit sends a signal to make the relay switch group act once through the relay drive unit. For example, the relay drive signal C1 sent by the controller unit in Fig. 6(a) changes by one pulse period , or the relay drive signal C2 sent by the controller unit in Fig. 6(b) changes one pulse period. The life counter is a software counter in the controller unit, the controller unit sends out a signal to make L relay switch groups act once, and the count value of the life counter is incremented by 1. At the same time, the on-off times of the L relays are respectively counted to obtain L action count values, which are respectively performed by the L switch group action count units outside the controller unit.

The method is to judge whether the relay switch group whose detection flag is in the state of inspection is invalid. The method is that the error between the number of times the relay switch group is controlled to be turned on and off and its action count value is less than E, then the relay switch group is not invalid, otherwise invalid. The specific judgment method is to take the count value of the current life counter modulo M to obtain the remainder Q; set the read action count value of the current relay switch group to be judged as K, then when |K-Q|<E is satisfied, or When |K-(Q-M)|<E, or one of |K-(Q+M)|<E, the error between the number of times the relay switch group is controlled to be on and off and its action count value is less than E. The action count value adopts the cyclic counting method. After the action count value reaches the maximum value M of the tri-state output counting circuit, adding 1 will overflow to 0; the 4-bit binary action count output by the tri-state output counting circuit embodiment 2 For example, the maximum count value M is 1111, and the count value of the next action is 0; in the above judgment expression, the comparison between K and Q-M is to offset the K value plus the count overflow, which is smaller and the Q value is larger. Influence; Comparing K with Q+M is to offset the larger K value and the smaller influence of the Q value on M modulo. Since E is an integer greater than or equal to 1 and less than or equal to M/2, after determining the error E, the maximum count value of the action count value must be greater than 2 times of E; for example, if E is determined to be 3, then the maximum count value of the action count value It must be greater than 6. At this time, the decimal BCD counter or the binary counter with more than 3 digits can meet the requirements. Among the L action count values read at the current time, the controller unit will no longer judge and process the action count values of the relays whose detection flags are in the stop-check state.

The following method can also be used to judge whether the relay switch group whose detection flag is in the state of inspection is invalid: when it is judged that the current action count value of the relay switch group to be judged is not related to the previous action count value, then the relay switch group Invalid, otherwise it is not invalid; or, if it is to be judged that the current action count value of the relay switch group for S consecutive times and the previous action count value are not in the relationship of incrementing by 1, then the relay switch group is invalid, otherwise it is not invalid; the S is Integer greater than or equal to 2. Since the action count value adopts the cyclic counting method, after the action count value reaches the maximum value of the tri-state output counting circuit, adding 1 will overflow to 0; Taking the count value as an example, its maximum value is 1111, and the next on-off count value that satisfies the relationship of increment by 1 is 0.

The following method can also be used to judge whether the relay switch group whose detection flag is in the state of inspection is invalid: when it is judged that the current operation count value of the relay switch group accumulatively reaching W times and the previous operation count value are not in the relationship of incrementing by 1, then The relay switch group fails, otherwise it does not fail; the W is an integer greater than or equal to 2.

The controller unit and the man-machine interface unit can realize the adjustment and display of the NO and NC duty ratio of the relay switch group (that is, to set the ratio of the pull-in time and the release time), the selection of the failure judgment method, and the setting and display of the failure judgment parameters. The action cycle setting and display of the switch group, etc. The relay life count measuring device can also add a temperature monitoring unit to monitor the temperature of the relay during the test.

Except for the technical features described in the specification, they are all conventional technologies mastered by those skilled in the art. For example, select the controller of the controller unit, design the relevant peripheral control circuit and compile the program to realize its function; select or design the gating control unit circuit to meet the requirements of decoding gating; select or design the drive circuit of the relay drive unit, Realizing the requirements for controlling the L relay switch groups; selecting the composition and circuit structure of the man-machine interface unit, connecting it with the controller unit, and realizing the corresponding functions; etc., are all conventional techniques mastered by those skilled in the art.

Claims (5)

1. A relay life count measuring device is characterized in that: the system comprises a controller unit, L switch group action counting units, a human-computer interface unit and a relay driving unit;

the human-computer interface unit is electrically connected to the controller unit and used for sending out a detection command and displaying the service life of the L relay switch groups; the controller unit is electrically connected to the relay driving unit and sends a relay driving signal to the relay driving unit to control the actions of the L relay switch groups; the L switch group action counting units respectively count the actions of the L relay switch groups to obtain L action counting values; the switch group action counting unit is electrically connected to the controller unit and used for respectively reading action counting values of the L switch group action counting units and controlling the clear 0 of the action counting values of the L switch group action counting units by the controller unit.

2. The relay life count measuring device according to claim 1, characterized in that: the switch group action counting unit is electrically connected to the controller unit, and the method for the controller unit to respectively read in the action counting values of the L switch group action counting units is that the action counting values of the L switch group action counting units are all output in a three-state buffer mode; the tri-state buffer output ports of all the switch group action counting units are all connected in parallel to the counting data input port of the controller unit; the controller unit sends out gating control signals to enable the three-state buffer output ports of the switch group action counting units one by one, and corresponding action counting values are read in from the counting data input port.

3. The relay life count measuring device according to claim 2, characterized in that: the device also comprises a gating control unit; the controller unit sends an address coding signal of the switch group action counting unit to the gating control unit, and the gating control unit decodes the address coding signal of the switch group action counting unit to obtain a gating control signal.

4. A relay life count measuring device according to any one of claims 1 to 3, wherein: the L switch group action counting units respectively comprise a pulse generating circuit, an RS trigger and a three-state output counting circuit, wherein the pulse generating circuit, the RS trigger and the three-state output counting circuit have the same structure and composition;

the pulse generating circuit outputs a first initial pulse and a second initial pulse generated by the action of the relay switch group; the RS trigger converts the input first initial pulse and the second initial pulse into a counting pulse after the edge jitter interference pulse is filtered; the tri-state output counting circuit counts the counting pulse and outputs an action counting value.

5. The relay life count measuring device according to claim 4, characterized in that: the relay switch group consists of a relay normally open switch and a relay normally closed switch in the same relay; the level change of the first initial pulse is consistent with the action change of a normally open switch in the relay switch group, and the level change of the second initial pulse is consistent with the action change of a normally closed switch in the relay switch group; when the normally open switch and the normally closed switch in the relay switch group are in all off states, the states of the first initial pulse and the second initial pulse output by the pulse generating circuit are both invalid signal input states of the RS trigger.

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