Fault alarm circuit for redundant power supply

Abstract

The utility model belongs to the field of switching power supplies, and discloses a fault alarm circuit for a redundant power supply, which comprises a multi-input voltage detection circuit, a logic judgment circuit and an execution circuit, the multi-input voltage detection circuit comprises a voltage sampling circuit, a reference voltage generation circuit and a comparator. The voltage sampling circuit is connected with the first input end of the comparator and is used for sampling multiple input voltages of the redundant power supply, converting the input voltages into first voltages and inputting the first voltages into the comparator; the reference voltage generation circuit is connected with the second input end of the comparator and used for generating reference voltage and inputting the reference voltage to the comparator; the comparator compares the first voltage with a reference voltage and outputs a second voltage according to a comparison result; the logic judgment circuit is connected with the comparator and the execution circuit and used for controlling the execution circuit to be turned off or turned on according to the second voltage. Detection of a plurality of input voltage points is realized through a single comparator, required components are few, and reduction of design cost and improvement of circuit reliability are facilitated.

Description

Technical Field

[0001] The utility model belongs to the field of switching power supplies, and in particular relates to a fault alarm circuit for a redundant power supply. Background Art

[0002] With the development of the power electronics industry, intelligence and high efficiency have become the inevitable trend of the development of switching power supplies. At the same time, the occasions in which power supplies can be applied are getting better and better, which poses a great challenge to the reliability of power supplies. In order to provide system reliability, it is often required to use multiple power supplies to form a redundant system. When an individual power supply fails, the redundant system can still work normally. In order to identify power failures and replace power supplies in time, the redundant system is required to have an input voltage abnormality (DC OK) alarm function. In order to solve this problem, the power supply often uses multiple power supply voltage points to make a judgment on the DC OK alarm function, but multiple voltage points mean that the design difficulty is further increased, reliability is difficult to guarantee, and cost is difficult to reduce. The utility model circuit uses a detection circuit to simplify the voltage detection of the switching power supply and realize the input voltage abnormality alarm function, thereby improving the design reliability of the power supply. Utility Model Content

[0003] The utility model aims to overcome the problem of using multiple comparators to compare multiple voltage points in the above-mentioned prior art, which results in complex circuits and high costs, and provides a single comparator to compare multiple voltage points to solve the problems of complex circuits and high costs; at the same time, it overcomes the problem of only being able to detect a single input voltage in the above-mentioned prior art, and provides a variable reference voltage, thereby realizing the input voltage abnormality alarm function for a wide input voltage.

[0004] The utility model provides a fault alarm circuit for redundant power supply, which comprises: a multi-input voltage detection circuit, a logic judgment circuit and an execution circuit;

[0005] The multi-input voltage detection circuit includes a voltage sampling circuit, a reference voltage generating circuit and a comparator; the voltage sampling circuit is connected to the first input terminal of the comparator, and the voltage sampling circuit is used to sample multiple input voltages of the redundant power supply and convert the sampled multiple input electrical signals into a first voltage and input it to the comparator; the reference voltage generating circuit is connected to the second input terminal of the comparator, and the reference voltage generating circuit is used to generate a reference voltage and input it to the comparator; the comparator compares the first voltage with the reference voltage and outputs a second voltage according to the comparison result;

[0006] The logic judgment circuit is connected to the comparator and the execution circuit respectively, and the logic judgment circuit is used to control the execution circuit to be turned off or on according to the second voltage.

[0007] Preferably, the reference voltage generating circuit collects the output voltage of the redundant power supply and converts the output voltage into a reference voltage.

[0008] Preferably, the reference voltage generating circuit includes a resistor R4 and a resistor R5; the voltage sampling circuit includes a resistor R1, a resistor R2 and a resistor R3; one end of the resistor R1 and one end of the resistor R2 are respectively connected to the first input end of the comparator, one end of the resistor R3 is connected to the first input end of the comparator, the other end of the resistor R3 is connected to one end of the resistor R4, and one end of the resistor R5 is respectively connected to the second input end of the comparator and the other end of the resistor R4, wherein the first input end of the comparator is the positive input end, the second input end of the comparator is the reverse input end, the voltage at the connection point of the resistor R1 and the resistor R3 is used as the first voltage, and the voltage at the connection point of the resistor R4 and the resistor R5 is used as the reference voltage.

[0009] Preferably, the logic judgment circuit includes a switch tube and a resistor R6, the first end of the switch tube is connected to the output end of the comparator through the resistor R6, the second end of the switch tube is connected to the execution circuit, and the third end of the switch tube is connected to the voltage source.

[0010] Preferably, the execution circuit is a relay or an optocoupler device.

[0011] The utility model also provides a fault alarm circuit for redundant power supply, which comprises: a multi-input voltage detection circuit, a logic judgment circuit and an execution circuit;

[0012] The multi-input voltage detection circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5 and a comparator, one end of the resistor R1 and one end of the resistor R2 are respectively connected to the positive input end of the comparator, one end of the resistor R3 is connected to the positive input end of the comparator, the other end of the resistor R3 is connected to one end of the resistor R4, and one end of the resistor R5 is respectively connected to the negative input end of the comparator and the other end of the resistor R4;

[0013] The logic judgment circuit includes a switch tube and a resistor R6, a first end of the switch tube is connected to the output end of the comparator through the resistor R6, a second end of the switch tube is connected to the execution circuit, and a third end of the switch tube is connected to the voltage source.

[0014] The utility model further provides a redundant power supply failure alarm circuit, which is characterized by comprising: a multi-input voltage detection circuit, a logic judgment circuit and an execution circuit;

[0015] The voltage sampling circuit includes a resistor R1, a resistor R2, a resistor R3 and a controllable precision voltage-stabilizing source, one end of the resistor R1 and one end of the resistor R2 are respectively connected to the reference end of the controllable precision voltage-stabilizing source, one end of the resistor R3 is connected to the reference end of the controllable precision voltage-stabilizing source, the other end of the resistor R3 is connected to the anode of the controllable precision voltage-stabilizing source, and the other end of the resistor R3 is connected to the ground;

[0016] The logic judgment circuit includes a switch tube and a resistor R6. The first end of the switch tube is connected to the cathode of a controllable precision voltage-stabilizing source, the second end of the switch tube is connected to the execution circuit, the third end of the switch tube is connected to the voltage source, one end of the resistor R6 is connected to the voltage source, and the other end of the resistor R6 is connected to the cathode of the controllable precision voltage-stabilizing source.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] (1) Multiple input voltage point detection is achieved through a single comparator, which requires fewer components and helps reduce design costs and improve circuit reliability.

[0019] (2) Existing fault alarm circuits generally have a given reference voltage, that is, the reference voltage is fixed. When the input is in a wide voltage range, a low voltage or undervoltage fault alarm cannot be realized. In the fault alarm circuit of the utility model, the reference voltage is obtained by dividing the output voltage. When the output voltage is high, the detection threshold of the input voltage is also increased, and the low voltage or undervoltage fault alarm function can be realized when the input is in a wide voltage range. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Attached Figure 1 A redundant system diagram used in the fault alarm circuit of the utility model;

[0021] Attached Figure 2 This is a circuit diagram of the first embodiment of the fault alarm circuit of the utility model;

[0022] Attached Figure 3 This is a circuit diagram of the second embodiment of the fault alarm circuit of the utility model. DETAILED DESCRIPTION

[0023] The present invention and its beneficial effects will be further described in detail below in conjunction with specific implementations and the accompanying drawings of the specification, but the specific implementations of the present invention are not limited thereto.

[0024] First embodiment

[0025] refer to Figure 1 , attached Figure 1 This is a redundant system diagram used in the fault alarm circuit of the utility model. The redundant system includes power supply 1, power supply 2, redundant power supply and load. Power supply 1 and power supply 2 are connected to the load through the redundant power supply.

[0026] refer to Figure 2 The fault alarm circuit provided in this embodiment is a fault alarm circuit used in a redundant power supply, which includes a multi-input voltage detection circuit 10, a logic judgment circuit 20 and an execution circuit 30.

[0027] The multi-input voltage detection circuit 10 includes a voltage sampling circuit 101, a reference voltage generating circuit 102 and a comparator U1; the voltage sampling circuit 101 is connected to the positive input terminal (first input terminal) of the comparator U1, and the voltage sampling circuit 101 is used to sample the input voltage V1+ and the input voltage V2+ of the redundant power supply and convert the sampled input voltage V1+ and the input voltage V2+ into a first voltage Va and input it to the comparator U1; the reference voltage generating circuit 102 is connected to the reverse input terminal (second input terminal) of the comparator U1, and the reference voltage generating circuit 102 is used to generate a reference voltage Vb and input it to the comparator U1; the comparator U1 is used to compare the first voltage Va with the reference voltage Vb and output a second voltage Vc according to the comparison result; in this embodiment, the reference voltage generating circuit 102 collects the output voltage Vo of the redundant power supply, and converts the output voltage Vo into a reference voltage Vb through resistors R4 and R5.

[0028] The logic judgment circuit 20 is connected to the comparator U1 and the execution circuit 30 respectively. The logic judgment circuit 20 is used to control the execution circuit 30 to be turned off or on according to the second voltage Vc.

[0029] Specifically, the voltage sampling circuit 101 includes a resistor R1, a resistor R2 and a resistor R3, and the reference voltage generating circuit 102 includes a resistor R4 and a resistor R5; one end of the resistor R1 and one end of the resistor R2 are respectively connected to the positive input terminal of the comparator U1, one end of the resistor R3 is connected to the first input terminal of the comparator U1, the other end of the resistor R3 is connected to one end of the resistor R4, and one end of the resistor R5 is respectively connected to the reverse input terminal of the comparator U1 and the other end of the resistor R4, wherein the voltage at the connection point of the resistor R4 and the resistor R5 is used as the reference voltage Vb, the voltage at the connection point of the resistor R1 and the resistor R3 is used as the first voltage Va, and the output end of the comparator U1 is used as the output point of the second voltage Vc.

[0030] The resistors R1, R2, and R3 serve to sample the input voltages V1+ and V2+, and the resistors R4 and R5 serve to sample the output voltage Vo, wherein the first voltage Va is:

[0031]

[0032] The reference voltage Vb is:

[0033]

[0034] It can be seen from the formula that when the input voltage V1+ or the input voltage V2+ is undervoltage, the level of the first voltage Va becomes smaller, then the first voltage Va is less than the reference voltage Vb, and the comparator U1 outputs a high level, that is, the second voltage Vc is a high level; when the input voltage V1+ or the input voltage V2+ is overvoltage, the reference voltage Vb becomes larger, then the first voltage Va is less than the reference voltage Vb, and the comparator U1 outputs a high level, that is, the second voltage Vc is a high level; when the input voltage V1+ or the input voltage V2+ is normal, the first voltage Va becomes larger, then the first voltage Va is greater than the reference voltage Vb, and the comparator U1 outputs a low level, that is, the second voltage Vc is a low level.

[0035] The logic judgment circuit 20 includes a transistor Q1 (switch tube) and a resistor R6. The first end (base) of the transistor Q1 is connected to the output end of the comparator U1 through the resistor R6, the second end (collector) of the transistor Q1 is connected to the execution circuit 30, and the third end (emitter) of the transistor Q1 is connected to the voltage source VCC. When the second voltage Vc output by the comparator U1 becomes low, the BE junction of the transistor Q1 is forward biased, and the transistor Q1 is saturated and turned on. When the second voltage Vc becomes high, the BE junction of the transistor Q1 is reverse biased, and the transistor Q1 is not turned on.

[0036] The execution circuit 30 is a relay K1. When the voltage at the second end of the transistor Q1 (the voltage at point d) is high, the 1st and 2nd pins of the relay K1 are energized, and the input voltage abnormality signal indicates normal. When the voltage at point d is low, the 1st and 2nd pins of the relay are disconnected, and the input voltage abnormality signal indicates abnormality. Through this characteristic, the fault signals of the input voltage V1+ and the input voltage V2+ can be detected. In this embodiment, the execution circuit 30 is a relay K1. In other embodiments, the execution circuit 30 can be an optical coupler device.

[0037] Compared with the prior art, the utility model has the following beneficial effects:

[0038] (1) The fault alarm circuit provided by the utility model realizes multiple input voltage point detection through a single comparator U1, which requires fewer components and is conducive to reducing design costs and improving circuit reliability.

[0039] (2) The fault alarm circuit provided by the present invention has a reference voltage Vb obtained by dividing the output voltage Vo. When the output voltage Vo is high, the detection thresholds (comparison thresholds) of the input voltage V1+ and the input voltage V2+ are also increased, thereby realizing the low voltage and undervoltage fault alarm function when the input is in a wide voltage range.

[0040] Second embodiment

[0041] refer to Figure 3This embodiment provides a fault alarm circuit, which includes a multi-input voltage detection circuit 10, a logic judgment circuit 20 and an execution circuit 30.

[0042] The multi-input voltage detection circuit 10 includes a resistor R1, a resistor R2, a resistor R3 and a controllable precision voltage regulator U1, one end of the resistor R1 and one end of the resistor R2 are respectively connected to the reference end of the controllable precision voltage regulator U1, one end of the resistor R3 is connected to the reference end of the controllable precision voltage regulator U1, the other end of the resistor R3 is connected to the anode of the controllable precision voltage regulator U1, and the other end of the resistor R3 is connected to the ground.

[0043] The logic judgment circuit 20 includes a switch tube Q1 and a resistor R6, a first end of the switch tube Q1 is connected to the cathode of the controllable precision voltage regulator U1, a second end of the switch tube Q1 is connected to the execution circuit 30, a third end of the switch tube Q1 is connected to the voltage source VCC, one end of the resistor R6 is connected to the voltage source VCC, and the other end of the resistor R6 is connected to the cathode of the controllable precision voltage regulator U1. The execution circuit 30 includes a relay K1. The fault alarm circuit provided in this embodiment can realize the alarm function of a narrow voltage range.

Claims

1. A fault alarm circuit for a redundant power supply, characterized in that: include: Multi-input voltage detection circuit, logic judgment circuit and execution circuit; The multi-input voltage detection circuit includes a voltage sampling circuit, a reference voltage generating circuit and a comparator; The voltage sampling circuit is connected to the first input terminal of the comparator, and the voltage sampling circuit is used to sample multiple input voltages of the redundant power supply and convert the sampled multiple input voltages into a first voltage and input it to the comparator; The reference voltage generating circuit is connected to the second input terminal of the comparator, and the reference voltage generating circuit is used to generate a reference voltage and input it into the comparator; The comparator compares the first voltage with the reference voltage and outputs a second voltage according to the comparison result; The logic judgment circuit is connected to the comparator and the execution circuit respectively, and the logic judgment circuit is used to control the execution circuit to be turned off or on according to the second voltage.

2. The fault alarm circuit for redundant power supply according to claim 1, characterized in that: The reference voltage generating circuit collects the output voltage of the redundant power supply and converts the output voltage into the reference voltage.

3. The fault alarm circuit for redundant power supply according to claim 1, characterized in that: The reference voltage generating circuit includes a resistor R4 and a resistor R5; the voltage sampling circuit includes a resistor R1, a resistor R2 and a resistor R3; one end of the resistor R1 and one end of the resistor R2 are respectively connected to the first input end of the comparator, one end of the resistor R3 is connected to the first input end of the comparator, the other end of the resistor R3 is connected to one end of the resistor R4, and one end of the resistor R5 is respectively connected to the second input end of the comparator and the other end of the resistor R4, wherein the first input end of the comparator is a positive input end, the second input end of the comparator is a reverse input end, the voltage at the connection point of the resistor R1 and the resistor R3 is used as the first voltage, and the voltage at the connection point of the resistor R4 and the resistor R5 is used as the reference voltage.

4. The fault alarm circuit for redundant power supply according to claim 1, characterized in that: The logic judgment circuit includes a switch tube and a resistor R6, the first end of the switch tube is connected to the output end of the comparator through the resistor R6, the second end of the switch tube is connected to the execution circuit, and the third end of the switch tube is connected to the voltage source.

5. The fault alarm circuit for redundant power supply according to claim 1, characterized in that: The execution circuit is a relay or an optocoupler device.

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