Testing device for electrical performance test

Abstract

The utility model belongs to the technical field of aeronautical manufacturing, and relates to an electrical performance test device, an airborne disc box piece comprises a plurality of relays and freewheeling diodes CR, the freewheeling diodes CR are connected in parallel at two ends of a relay coil RL, the test device comprises a plurality of test units connected in parallel, the number of the test units is the same as that of the relays of the airborne disc box piece, and the relays are connected in parallel. According to the utility model, the oscilloscope is adopted to check the performance of the fly-wheel diode in which the relay coil is connected in parallel, so that the open-circuit characteristic of the fly-wheel diode caused by manufacturing processes such as welding overheating and the like can be quickly diagnosed; a relay contact on-off inspection mode is innovated, a three-purpose meter resistance gear conduction method is replaced by lightening of light-emitting diodes with different colors, the on-off state of the relay contact is judged visually, and the test efficiency and safety are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of aviation manufacturing and relates to an electrical performance test device which is used for electrical performance test of airborne disk box parts. Background Art

[0002] Airborne trays and boxes are mainly used to control the states of various signals when airborne equipment is cross-linked. There are many types of them, and the signal control is complex, including relay boxes, landing gear signal boxes, centralized key-destroying relay boxes, etc. The quality of their performance directly affects the state conversion of various signals, and may cause flight accidents in serious cases. At present, when testing airborne trays and boxes, the relay coil is directly powered on the relevant pins and sockets of the tray and box electrical connector, and the relay contact isolation switch state conversion, diode characteristics and other parameters are directly measured on the relevant pins and sockets using a multimeter to judge the performance of the airborne tray and box. Its disadvantages are that the number of pins of the airborne tray and box electrical connector is large, the specifications are different, and the distance is close. When powered on, short circuits and poor contact may occur, and the test safety is poor; it is not easy to find the required measurement points, and the test efficiency is low. There is a lack of effective detection means for the diode (i.e., freewheeling diode) connected in parallel with the relay coil, because the forward and reverse resistance values ​​of the freewheeling diode are generally greater than or similar to the resistance value of the coil, and the resistance range of the multimeter cannot be used to judge the quality of the freewheeling diode. Utility Model Content

[0003] The purpose of the utility model is to provide an electrical performance test device, which innovates the inspection method for the on-off of the freewheeling diode and the relay contact of the onboard disk box, and judges the performance of the freewheeling diode by the waveform change of the oscilloscope connected in parallel at both ends of the relay coil at the moment of power failure of the relay; innovates the on-off state inspection method of the relay contact, and uses a light-emitting diode and a parallel step-down current-limiting resistor as the load of the relay contact circuit. The on-off state of the normally open contact and the normally closed contact of the relay when the coil is powered on and off can be judged by observing the lighting and extinguishing of the light-emitting diode. The inspection method of the device of the utility model is intuitive, reliable, and easy to operate, and is convenient for the inter-process inspection and final inspection of the electrical performance of the onboard disk box.

[0004] Technical solution:

[0005] An electrical performance test device, an onboard disk box includes a plurality of relays and a freewheeling diode CR, the freewheeling diode CR is connected in parallel at both ends of a relay coil RL, the test device includes a plurality of parallel test units, the number of the test units is the same as the number of relays of the onboard disk box, the test units are connected one-to-one with the relays of the onboard disk box, and the test units are connected to an oscilloscope.

[0006] Furthermore, the test unit includes a DC power supply, a fuse F, an isolating switch K, a plurality of light-emitting diodes D, and a voltage-dividing and current-limiting resistor R whose number is the same as the number of light-emitting diodes D. The positive electrode of the DC power supply is connected to the negative electrode of the freewheeling diode CR via the fuse F and the isolating switch K, and the negative electrode of the DC power supply is connected to the positive electrode of the freewheeling diode CR; the positive electrode of the DC power supply returns to the negative electrode of the DC power supply via the fuse F, the contacts of the relay, the light-emitting diode D, and the voltage-dividing and current-limiting resistor R.

[0007] Furthermore, the positive electrode of the DC power supply is connected to the static contact of the relay via a fuse F, each moving contact of the relay is respectively connected to the positive electrode of the corresponding light-emitting diode D, and the negative electrode of the light-emitting diode D is connected to the negative electrode of the DC power supply via a voltage-dividing and current-limiting resistor R.

[0008] Further, the positive electrode of the oscilloscope probe is connected to the negative electrode of the freewheeling diode CR, and the negative electrode of the oscilloscope probe is connected to the positive electrode of the freewheeling diode CR.

[0009] Furthermore, the DC power supply is +28V.

[0010] Furthermore, a power-on indicator light H is included, and the power-on indicator light H is connected in parallel to both ends of the freewheeling diode CR.

[0011] Furthermore, the number of the light emitting diodes D and the number of the voltage-dividing and current-limiting resistors R are both four.

[0012] Beneficial effects:

[0013] Compared with the prior art, the utility model has the following advantages: the utility model uses an oscilloscope to check the performance of the freewheeling diode in parallel with the relay coil, so as to quickly diagnose the open circuit characteristics of the freewheeling diode caused by the manufacturing process such as welding overheating; an innovative relay contact on-off inspection method is used, in which the lighting of light-emitting diodes of different colors is used instead of the resistance conduction method of a multimeter, so that the on-off state of the relay contact can be judged intuitively, thereby improving the test efficiency and safety; with different process cables, the utility model can complete the electrical performance tests of various types of airborne disk boxes and has wide versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the test unit of the utility model;

[0015] Figure 2 It is the electrical principle diagram of the utility model;

[0016] Figure 3 This is the electrical schematic diagram of a certain type of relay box;

[0017] Figure 4 An electrical schematic diagram for testing a certain type of relay box using the utility model;

[0018] Figure 5 The utility model is used to test the process cable connection diagram of a certain type of relay box. DETAILED DESCRIPTION

[0019] Combined with the accompanying drawings, an electrical performance test device of the present invention is described in detail to check the electrical performance of a certain type of relay box:

[0020] A certain type of relay box consists of 9 relays and 28 sets of contacts. Its electrical schematic is shown in Figure 3 In order to use this device to complete the performance inspection test of this type of relay box, a test relationship configuration table should be established in the relay box test process file. The configuration table should clearly define the measurement points of the reverse electromotive force of each relay coil in the relay box on the universal test device, and the corresponding relationship between the normally open and normally closed contacts of each relay and the light-emitting diode of the universal test device. The basis for establishing the configuration table is the schematic diagram of the relay box and a universal test device for electrical performance testing of an onboard disk box, see respectively Figure 3 and Figure 2 The test relationship configuration table of a certain type of relay box is shown in Table 1. The electrical schematic diagram of a certain type of relay box is checked using a general test device for electrical performance test of an onboard panel box. Figure 4 .

[0021] Table 1 Corresponding configuration table of a certain type of relay box test

[0022]

[0023]

[0024] During the test, the J0 socket of a general test device for the electrical performance test of an onboard panel box is connected to the J1, J2, and J3 sockets of a certain type of relay box using a process cable. The connection diagram is shown in Figure 5 The J0 plug of the process cable is connected to the J0 socket of a general test device for electrical performance test of an onboard disk box, and the other end of the cable is divided into three-way plugs J0-1, J0-2, and J0-3, which are respectively connected to the J1, J2, and J3 sockets of a certain type of relay box.

[0025] Connect Figure 4The K0 switch in the relay box supplies a DC 28V power supply to the contacts of a certain type of relay box. The 28 green LEDs with odd numbers among the D1~D56 LEDs light up, and the 28 red LEDs with even numbers do not light up, indicating that when the relay coil of a certain type of relay box is not powered, all normally closed contacts are connected and all normally open contacts are disconnected; turn on the K1 switch to power the relay coil RL1. At this time, the green LEDs D1, D3, D5, D7, D9, and D11 should go out, and the red LEDs D2, D4, D6, D8, D10, and D13 should light up, indicating that the conversion status of the 6 groups of contacts controlled by the coil RL1 is normal, the normally closed contacts are disconnected, and the normally open contacts are connected; connect the positive pole of the oscilloscope probe to the RL1-1 test hole and the negative pole of the probe to the RL1-2 test hole, disconnect the K1 switch, and observe whether there is an instantaneous high-voltage reverse electromotive force on the oscilloscope. If not, it means that the characteristics of the CR1 freewheeling diode connected in parallel with the RL1 coil are intact. According to the corresponding configuration table in Table 1, connect K2~K9 respectively, check whether the corresponding freewheeling diode characteristics and contact conversion relationship are normal, and complete the electrical performance inspection of a certain type of relay box.

[0026] For different types of airborne disk boxes, different process cables are equipped and a test correspondence configuration table is established in the test process file. The device can be used to complete the electrical performance test of different types of airborne disk boxes, and has wide versatility.

[0027] The test method for the freewheeling diode is as follows: based on the role of the freewheeling diode in the onboard disk box, the test is carried out in two states: with and without the freewheeling diode in the relay coil, and the voltage change at both ends of the relay coil when the power is off in the two states is measured with an oscilloscope. During the inspection, an isolating switch needs to be set between the relay and the DC power supply to isolate the induced electromotive force from the DC power supply, so as to facilitate the measurement of the characteristics of the induced electromotive force with an oscilloscope; during measurement, the oscilloscope should be set to the "single scan" mode to capture the rapidly changing induced electromotive force.

[0028] When a certain type of relay coil used in the test is not connected in parallel with a freewheeling diode, the reverse peak value of the induced electromotive force generated at the moment of power failure can reach 300V. The peak value is determined by parameters such as the iron core material and cross-sectional area of ​​the relay electromagnet, and the number of coil turns. When a freewheeling diode is connected in parallel at both ends of the coil, the reverse peak value at the moment of power failure is about 640mV, which is consistent with the forward conduction voltage drop of the diode.

[0029] Judgment basis: Using an isolating switch and an oscilloscope can effectively check the open circuit fault of the freewheeling diode in parallel with the relay coil. If the freewheeling diode is open, it cannot provide a discharge circuit for the induced electromotive force. There will be a higher reverse peak voltage on the oscilloscope. If the freewheeling diode is short-circuited, fuse F will burn out when the relay coil is energized.

[0030] The method for checking the on / off state of the relay contacts is as follows: use the light-emitting diode and the voltage-limiting current-limiting resistor as the load of the main circuit of the contact, power on the main circuit of the contact, and determine the on / off state of the corresponding contact by whether the light-emitting diode is lit or not. Set a green light-emitting diode to the normally closed contact circuit of the relay, and a red light-emitting diode to the normally open contact circuit of the relay. When the relay coil is not powered, the green light-emitting diode lights up and the red light-emitting diode does not light up, indicating that the normally closed contact is connected and the normally open contact is disconnected; when the relay coil is powered, the green light-emitting diode goes out and the red light-emitting diode lights up, indicating that the normally closed contact is disconnected and the normally open contact is connected. The judgment of the on / off state conversion of the relay contacts is intuitive and clear at a glance.

Claims

1. An electrical performance test device, used for electrical performance test of onboard disk box, the onboard disk box includes a number of relays and a freewheeling diode CR, the freewheeling diode CR is connected in parallel at both ends of the relay coil RL, characterized in that: The test device comprises a plurality of test units connected in parallel, the number of the test units is the same as the number of relays of the onboard disk box, the test units are connected to the relays of the onboard disk box in a one-to-one correspondence, and the test units are connected to an oscilloscope; Among them, the test unit includes a DC power supply, a fuse F, an isolating switch K, a plurality of light-emitting diodes D and a voltage-dividing and current-limiting resistor R whose number is the same as the number of light-emitting diodes D. The positive electrode of the DC power supply is connected to the negative electrode of the freewheeling diode CR via the fuse F and the isolating switch K, and the negative electrode of the DC power supply is connected to the positive electrode of the freewheeling diode CR; the positive electrode of the DC power supply returns to the negative electrode of the DC power supply via the fuse F, the contacts of the relay, the light-emitting diode D and the voltage-dividing and current-limiting resistor R.

2. An electrical performance test device according to claim 1, characterized in that: The positive electrode of the DC power supply is connected to the static contact of the relay via a fuse F, each moving contact of the relay is respectively connected to the positive electrode of the corresponding light-emitting diode D, and the negative electrode of the light-emitting diode D is connected to the negative electrode of the DC power supply via a voltage-dividing current-limiting resistor R.

3. An electrical performance test device according to claim 1, characterized in that: The positive electrode of the oscilloscope probe is connected to the negative electrode of the freewheeling diode CR, and the negative electrode of the oscilloscope probe is connected to the positive electrode of the freewheeling diode CR.

4. The electrical performance test device according to claim 1, characterized in that: The DC power supply is +28V.

5. The electrical performance test device according to claim 1, characterized in that: The device also includes a power-on indicator light H, which is connected in parallel to both ends of the freewheeling diode CR.

6. The electrical performance test device according to claim 1, characterized in that: The number of the light emitting diodes D and the number of the voltage dividing and current limiting resistors R are both four.

Images