Output voltage detection circuit

Abstract

The utility model relates to an output voltage detection circuit which comprises a detection circuit electrically connected with a voltage output end and an isolation control circuit. The detection circuit is electrically connected with the isolation control circuit; the output end of the isolation control circuit is electrically connected with an execution circuit which is electrically connected with a power supply circuit. The execution circuit is electrically connected to output a detection result. The device is reasonable in design, compact in structure and convenient to use.

Description

TECHNICAL FIELD

[0001] The utility model relates to output voltage detection circuit, especially in a kind of detection circuit of whether the output voltage of multiple combination power supply is normal. BACKGROUND

[0002] In the combination power supply of direct current to direct current multi-output, due to the number of output is more, and distribution to the multiple system use of rear stage, go to complex, thus frequently need to monitor the output of one or several, to judge whether each output is normal work, whether the required voltage is provided normally.

[0003] At present, the detection method commonly used in market is that output voltage is directly outputted after passing through current-limiting resistance, and the circuit is relatively simple, but there are more reference ground, cannot be isolated, energy consumption is higher, and the output efficiency is lowered and the like defects.Simultaneously in the application of multiple combination output power supply, there is often the case of tens of output or even dozens of output, when more of them are monitored, the existing scheme in market is used, and more connector point number is occupied, and connection is difficult. UTILITY MODEL CONTENT

[0004] The utility model wants to solve the technical problem and provides an output voltage detection circuit.The utility model scheme realizes higher precision, high reliability, low cost by fewer components, and sampling voltage and detection signal can be isolated, and 2-way or more outputs can be monitored in series according to demand, that is, when any one output is powered off, fault signal can be outputted, and the defects of the general scheme in market are effectively avoided.

[0005] To solve the above problems, the technical scheme adopted by the utility model is:

[0006] An output voltage detection circuit, including the detection circuit of electric connection voltage output end and isolation control circuit;Detection circuit and isolation control circuit are electrically connected;

[0007] The execution line is electrically connected to the output end of isolation control circuit, and the execution line is electrically connected to the power supply line;Execution line is electrically connected for outputting detection result.

[0008] As a further improvement of the above technical scheme:

[0009] The execution line includes a plurality of parallel execution units;

[0010] Isolation control circuit includes a plurality of independent isolation control units;

[0011] Detection circuit includes a plurality of independent detection units.

[0012] One input terminal is connected to optocoupler U1 through current-limiting resistor R3 and Zener diode D1. One output terminal of optocoupler U1 is connected to the external detection signal reference ground as a reference, and the other is connected to the gate of MOSFET Q1. The source of MOSFET Q1 outputs the detection result. The drain of MOSFET Q1 is connected to a 5V power supply through a common current-limiting resistor R1. The 5V power supply is connected to the gate of MOSFET Q1 through a pull-down resistor R2. Resistor R4 is electrically connected between the source and gate of MOSFET Q1.

[0013] The detection unit includes a current-limiting resistor R3 and a Zener diode D1 that are electrically connected.

[0014] The isolation control unit includes an optocoupler U1;

[0015] The execution unit includes MOSFET Q1 and resistors R2 and R4.

[0016] The resistance value of the current limiting resistor R3 is: (output voltage - 1V - Zener voltage of Zener diode D1) / (normal conduction current of optocoupler U1).

[0017] The power supply line includes a 5V power supply and a current-limiting resistor R1 that is electrically connected to the 5V power supply.

[0018] The output terminal of the execution line is equipped with a decoupling capacitor C1, which is located between the 5V power supply and the detection signal reference ground.

[0019] This invention achieves high precision, high reliability, and low cost with fewer components. It also isolates the sampling voltage and detection signal, and allows for cascade monitoring of two or more outputs as needed. Its advantages include low cost and high reliability. Attached Figure Description

[0020] Figure 1 This is a block diagram of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0022] like Figure 1 , Figure 2 This utility model includes a detection circuit electrically connected to the voltage output terminal and an isolation control circuit; the detection circuit and the isolation control circuit are electrically connected.

[0023] The output of the isolation control line is electrically connected to the execution line, and the execution line is electrically connected to the power supply line; the execution line is electrically connected to output the detection result.

[0024] The execution circuit consists of several parallel execution units;

[0025] The isolation control circuit includes several independent isolation control units;

[0026] The detection circuit comprises several independent detection units;

[0027] As Figure 2 The execution unit is preferably 5 groups, corresponding to the respective isolated control units;

[0028] The five detection units respectively comprise voltage stabilizing tubes D1, D2, D3, D4 and D5, which can be selected according to the output voltages of the corresponding outputs 1, 2, 3, 4 and 5. If high detection precision is required, a model with a voltage close to the output voltage can be selected, and if low detection precision is required, a model with a large difference from the output voltage can be selected.

[0029] The five corresponding isolated control units respectively comprise optocouplers U1, U2, U3, U4 and U5, which can be selected to have a relatively high transmission and provide more current to the subsequent stage.

[0030] Further, the five detection units are respectively provided with current limiting resistors R3, R6, R9, R12 and R15, and the current limiting resistors R3, R6, R9, R12 and R15 are selected to have a resistance value of (output voltage-1V-voltage stabilizing value of voltage stabilizing tube) / (normal conduction current of optocoupler).

[0031] In the execution circuit, Q1, Q2, Q3, Q4 and Q5 are MOS tubes, which should be selected to have a small size and a low opening voltage.

[0032] R2, R4, R5, R7, R8, R10, R11, R13, R14 and R16 respectively provide driving voltages for the MOS tubes Q1, Q2, Q3, Q4 and Q5, and it should be noted that their values should satisfy upper arm / lower arm=1 / 3 to meet the normal opening voltage of the MOS tubes.

[0033] The power supply circuit provides a 5V power supply, and R1 is a current limiting resistor which is selected according to the required current of the external detection signal.

[0034] The output end of the execution circuit is provided with a decoupling capacitor C1 to prevent the detection signal from being disturbed by external noise signals.

[0035] The scheme of the utility model carries out sampling detection on the output voltage with high precision, compares with the set value, and then performs control action on the TTL level through the isolated control part. When the output voltage is at a normal value, the detection result outputs a high level to the outside; when the output voltage is lower than the normal value, the detection result outputs a low level to the outside; and an external LED lamp can monitor the output result.

[0036] As a specific application, in the first road, the input end passes through the current limiting resistor R3, the voltage stabilizing tube D1 and accesses the optical coupler U1, the output end of the optical coupler U1 is externally connected with the detection signal reference ground, as a reference, one road accesses the gate of the MOS transistor Q1, the source of the MOS transistor Q1 outputs the detection result, the drain of the MOS transistor Q1 accesses the 5V power supply through the shared current limiting resistor R1, the 5V power supply accesses the gate of the MOS transistor Q1 through the pull-down resistor R2, and the resistor R4 is electrically connected between the source and the gate of the MOS transistor Q1;

[0037] The reference voltage is set by the one-way external connection of the detection signal reference ground of the output end of the optical coupler U1, the input signal passes through the current limiting resistor R3 and the voltage stabilizing tube D1, and then the signal enters the optical coupler U1, when the input signal is greater than the set threshold, the optical coupler U1 is turned on, the MOS transistor Q1 is triggered to be turned on, so that the detection result output is realized.

[0038] The second road to the fifth road is the same as the first road, and details are not repeated.

[0039] The utility model fully describes is in order to disclose more clearly, and for prior art is not enumerated one by one again.

[0040] Finally, it should be pointed out that: the above examples are only used to illustrate the technical scheme of the utility model, and are not limited thereto; although the utility model has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical scheme recorded in the foregoing examples, or make equivalent replacement to part of the technical features; as it is obvious for those skilled in the art to combine the plurality of technical schemes of the utility model. And these modifications or replacements do not make the essence of the corresponding technical scheme deviate from the spirit and scope of the technical scheme of the utility model embodiment. The technical content not described in the utility model is all known technology.

Claims

1. An output voltage detection circuit, characterized by: The detection circuit is electrically connected with the voltage output end, and the isolation control circuit is electrically connected with the detection circuit; The execution circuit is electrically connected with the power supply circuit; The execution circuit is electrically connected with the power supply circuit; 2. The output voltage detection circuit according to claim 1, characterized in that: The execution circuit is electrically connected with the power supply circuit; The execution circuit includes a plurality of parallel execution units; The isolation control circuit includes a plurality of independent isolation control units; The detection circuit includes a plurality of independent detection units.

3. The output voltage detection circuit according to claim 2, wherein: the input end is connected to the optocoupler U1 through the current-limiting resistor R3 and the voltage stabilizing tube D1, one way of the output end of the optocoupler U1 is connected to the detection signal reference ground as a reference, and the other way is connected to the gate of the MOS tube Q1; the source of the MOS tube Q1 outputs the detection result; the drain of the MOS tube Q1 is connected to the 5V power supply through the shared current-limiting resistor R1; the 5V power supply is connected to the gate of the MOS tube Q1 through the pull-down resistor R2; and the resistor R4 is electrically connected between the source and the gate of the MOS tube Q1.

4. The output voltage detection circuit according to claim 3, wherein: the detection unit includes the current-limiting resistor R3 and the voltage stabilizing tube D1 which are electrically connected; The isolation control unit includes the optocoupler U1; The execution unit includes the MOS tube Q1 and the resistors R2 and R4. The resistance value of the current-limiting resistor R3 is: (output voltage-1V-voltage stabilizing value of the voltage stabilizing tube D1) / (normal conduction current of the optocoupler U1).

5. The output voltage detection circuit of claim 3, wherein: The power supply circuit includes the 5V power supply and the current-limiting resistor R1 which is electrically connected with the 5V power supply.

6. The output voltage detection circuit of claim 5, wherein: The execution circuit output end is provided with the decoupling capacitor C1, and the decoupling capacitor C1 is arranged between the 5V power supply and the detection signal reference ground.

7. The output voltage detection circuit of claim 5, wherein: ​

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