Novel electronic current relay control system

Abstract

The utility model discloses a novel electronic current relay control system which comprises a current relay J, a switching tube Q, a holding circuit S, a comparator A, a reference voltage circuit H, a transformer T1, a sampling resistor R1 and a current transformer T2. The primary side of the transformer T1 and the primary side of the current transformer T2 are connected with the current input terminal I; the secondary side of the transformer T1 provides a working power supply for the current relay J, the reference voltage circuit H and the comparator A; the sampling resistor R1 is connected to the secondary side of the current transformer T2; the first input end of the comparator A is connected with the sampling resistor R1, and the second input end of the comparator A is connected with the reference voltage circuit H. The utility model provides a novel electronic current relay control system which does not need an auxiliary power supply, can directly replace a coil armature type current relay and can ensure the precision performance of the electronic current relay.

Description

Technical Field

[0001] The utility model relates to a novel electronic current relay control system, belonging to the technical field of electronic current relays. Background Art

[0002] At present, a current relay is an electrical device that causes a predetermined step change in the controlled quantity in the electrical output circuit when the change in the input quantity of the loop current (excitation current value) reaches the specified requirement.

[0003] The existing current relay is a coil-armature relay. When the current passing through the coil reaches the set value, the electrical contacts are driven by the action of the armature. When used on rail vehicles, the coil-armature relay is greatly affected by the vibration of the vehicle. The resistance of the relay contact changes greatly during the operation of the vehicle, which easily leads to unstable feedback signals. Summary of the invention

[0004] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a novel electronic current relay control system which does not require an auxiliary power supply, can directly replace the coil-armature current relay and can ensure the precision performance of the electronic current relay.

[0005] In order to solve the above technical problems, the technical solution of the utility model is:

[0006] A novel electronic current relay control system includes a current relay J, a switch tube Q, a holding circuit S, a comparator A, a reference voltage circuit H, a transformer T1, a sampling resistor R1 and a current transformer T2;

[0007] The primary side of the transformer T1 and the primary side of the current transformer T2 are both connected to the current input terminal I;

[0008] The secondary side of the transformer T1 provides working power for the current relay J, the reference voltage circuit H and the comparator A;

[0009] The sampling resistor R1 is connected to the secondary side of the current transformer T2;

[0010] The first input terminal of the comparator A is connected to the sampling resistor R1, and the second input terminal of the comparator A is connected to the reference voltage circuit H;

[0011] The input end of the holding circuit S is connected to the output end of the comparator A, and the output end of the holding circuit S is connected to the switch tube Q;

[0012] The switch tube Q is connected to the control end of the current relay J.

[0013] Furthermore, the transformer T1 is a through-type source transformer.

[0014] Furthermore, the current transformer T2 is a through-hole precision current transformer.

[0015] Furthermore, a rectification module D1 is connected to the secondary side of the transformer T1.

[0016] Furthermore, a rectification module D2 is connected to the secondary side of the current transformer T2.

[0017] Furthermore, both the rectification module D1 and the rectification module D2 adopt rectification chips.

[0018] Furthermore, a filter capacitor C1 is connected to the secondary side of the transformer T1.

[0019] With the above technical solution, the utility model adds a through-hole source-taking transformer to the control circuit of the current relay, so that the current relay does not require an auxiliary power supply, and the current relay can be applied to more occasions. In addition, through sampling by a through-hole precision current transformer and precise current control by a comparator, the accuracy and stability of the current relay can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a circuit schematic diagram of a novel electronic current relay control system of the utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to make the content of the utility model easier to be clearly understood, the following further details the utility model according to specific embodiments and in conjunction with the drawings.

[0022] As Figure 1 shown, this embodiment provides a novel electronic current relay control system, which includes a current relay J, a switching tube Q, a holding circuit S, a comparator A, a reference voltage circuit H, a transformer T1, a sampling resistor R1 and a current transformer T2.

[0023] The transformer T1 is a through-hole source-taking transformer, and the current transformer T2 is a through-hole precision current transformer.

[0024] The primary sides of both the transformer T1 and the current transformer T2 are connected to the current input terminal I.

[0025] The secondary side of the transformer T1 provides a working power supply for the current relay J, the reference voltage circuit H and the comparator A.

[0026] The sampling resistor R1 is connected to the secondary side of the current transformer T2;

[0027] The first input terminal of comparator A is connected to sampling resistor R1, and the second input terminal of comparator A is connected to reference voltage circuit H. The input voltage of comparator A for comparison comes from reference voltage REF and sampling resistor R1 of current transformer T2. The chip model of comparator A in this embodiment is CD4013.

[0028] The input terminal of holding circuit S is connected to the output terminal of comparator A, and the output terminal of holding circuit S is connected to switching transistor Q. The on / off state of switching transistor Q is controlled by the output of comparator A and the subsequent holding circuit S. Holding circuit S is implemented by combining a resistor-capacitor delay with a trigger circuit, which is equivalent to a delay circuit. Since the novel electronic current relay control system in this embodiment is applied to a rail train, upon receiving requirements from the traction system, the relay needs to act when there is overcurrent, and at the same time, a holding time of 30 ms is required.

[0029] Switching transistor Q is connected to the control terminal of current relay J, and the control terminal of current relay J is controlled by switching transistor Q.

[0030] As Figure 1 shown, a rectification module D1 is connected to the secondary side of transformer T1 in this embodiment, and a rectification module D2 is connected to the secondary side of current transformer T2. The outputs of the secondary sides of transformer T1 and current transformer T2 are rectified by rectification module D1 and rectification module D2 respectively. Rectification modules D1 and D2 in this embodiment both use rectification chips, and the model of the rectification chip is MB10S.

[0031] As Figure 1 shown, a filter capacitor C1 is connected to the secondary side of transformer T1 in this embodiment, and the secondary side of transformer T1 is filtered by filter capacitor C1.

[0032] The working principle of the present utility model is as follows:

[0033] When the current terminal I is powered on to connect the circuit, the through-core extraction transformer T1 provides the working power supply for the current relay J, eliminating the requirement for an external auxiliary power supply. At the same time, the current value flowing through is detected by the through-core precision current transformer T2, compared with the set threshold by comparator A, and then the output of the current relay J is controlled to meet the requirement of precise current control.

[0034] In the above specific embodiments, the technical problems solved, technical solutions, and beneficial effects of the present utility model are further described in detail. It should be understood that the above are only specific embodiments of the present utility model and are not used to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A new type of electronic current relay control system, characterized in that: It includes a current relay J, a switch tube Q, a holding circuit S, a comparator A, a reference voltage circuit H, a transformer T1, a sampling resistor R1 and a current transformer T2; The primary side of the transformer T1 and the primary side of the current transformer T2 are both connected to the current input terminal I; The secondary side of the transformer T1 provides working power for the current relay J, the reference voltage circuit H and the comparator A; The sampling resistor R1 is connected to the secondary side of the current transformer T2; The first input terminal of the comparator A is connected to the sampling resistor R1, and the second input terminal of the comparator A is connected to the reference voltage circuit H; The input end of the holding circuit S is connected to the output end of the comparator A, and the output end of the holding circuit S is connected to the switch tube Q; The switch tube Q is connected to the control end of the current relay J.

2. The novel electronic current relay control system according to claim 1 is characterized in that: The transformer T1 is a through-type source transformer.

3. The novel electronic current relay control system according to claim 1 is characterized in that: The current transformer T2 is a through-type precision current transformer.

4. The novel electronic current relay control system according to claim 1 is characterized in that: The secondary side of the transformer T1 is connected to a rectifier module D1 .

5. The novel electronic current relay control system according to claim 4 is characterized in that: The secondary side of the current transformer T2 is connected to a rectifier module D2.

6. The novel electronic current relay control system according to claim 5 is characterized in that: The rectifier module D1 and the rectifier module D2 both use rectifier chips.

7. The novel electronic current relay control system according to claim 1 is characterized in that: The secondary side of the transformer T1 is connected to a filter capacitor C1.

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