CN219247461U - Protection circuit - Google Patents
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- CN219247461U CN219247461U CN202223425225.0U CN202223425225U CN219247461U CN 219247461 U CN219247461 U CN 219247461U CN 202223425225 U CN202223425225 U CN 202223425225U CN 219247461 U CN219247461 U CN 219247461U
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Abstract
The utility model discloses a protection circuit which comprises a sampling circuit, a pre-stage filter circuit, a full-wave rectifying and proportional amplifying circuit and a control circuit, wherein the sampling circuit is connected with the pre-stage filter circuit; the sampling circuit collects electric signals; the pre-stage filter circuit performs transient suppression and RC filtering on the electric signal and then transmits the electric signal to the full-wave rectifying and proportional amplifying circuit; the full-wave rectification and proportional amplification circuit is used for full-wave rectification of the current signal and then amplifying the current signal, and the amplified direct current signal is transmitted to the control circuit; the control circuit comprises an MCU circuit and a power supply control circuit, and the MCU circuit controls the on-off of the power supply control circuit according to the amplified direct current signal. By collecting the output voltage value and the load current value and comparing the upper limit threshold value, the lower limit threshold value and the overload threshold value, the simultaneous ignition, short circuit and overload protection are realized, other circuits are not needed, and the circuit manufacturing cost is reduced.
Description
Technical Field
The utility model relates to the field of high-voltage power supply protection, in particular to a protection circuit.
Background
The static eliminating rod is fixed static eliminating equipment, has the characteristics of metal casing, firmness, beautiful appearance, strong wind power, quick and fast static eliminating and dust eliminating, and is suitable for automatic static eliminating and dust eliminating device.
However, when an ac high-voltage power supply is configured for the static electricity eliminating rod, the high-voltage power supply is often in an open loop state, and no high-voltage power supply protection measures are taken, so that overload, short circuit, high-voltage wire ignition or needle point ignition of the high-voltage power supply can occur, explosion or fire disaster can occur in a flammable and explosive or dusty working environment, and production safety accidents such as property loss, casualties and the like are caused.
Aiming at the problem of ignition of a high-voltage power supply, china patent CN106655084A discloses an ignition protection device of the high-voltage generator, but the ignition protection device can only realize ignition protection, but cannot realize overload and short-circuit protection of the high-voltage power supply.
Disclosure of Invention
The utility model aims to provide a protection circuit which can prevent explosion or fire of a high-voltage power supply in overload, short circuit and sparking working states.
In order to solve the technical problems, the utility model provides a protection circuit, which comprises a sampling circuit, a pre-stage filter circuit, a full-wave rectifying and proportional amplifying circuit and a control circuit;
the sampling circuit collects electric signals;
the pre-stage filter circuit performs transient suppression and RC filtering on the electric signal and then transmits the electric signal to the full-wave rectifying and proportional amplifying circuit;
the full-wave rectification and proportional amplification circuit is used for full-wave rectification of the current signal and then amplifying the current signal, and the amplified direct current signal is transmitted to the control circuit;
the control circuit comprises an MCU circuit and a power supply control circuit, and the MCU circuit controls the on-off of the power supply control circuit according to the amplified direct current signal.
Further, the sampling circuit comprises a high-voltage resistor; the high-voltage resistor is a high-voltage glass glaze resistor; the sampling circuit collects the electric signals of the high-voltage resistor.
Further, the sampling circuit further comprises a first resistor, and the high-voltage resistor and the first resistor are connected in series and then grounded.
Further, the pre-stage filter circuit comprises a bidirectional trigger diode, a first operational amplifier input follower, a second resistor, a first capacitor, a second capacitor, a third capacitor and a fourth capacitor;
the two ends of the diac are connected in parallel with the two ends of the first capacitor, the first capacitor is connected with the second capacitor in parallel, one ends of the first capacitor and the second capacitor are grounded, and the second resistor is connected between the other ends of the first capacitor and the second capacitor; the second resistor is connected with the positive input end of the first operational amplifier input follower, the negative input end of the first operational amplifier input follower is connected with the output end of the first operational amplifier input follower, and the output end of the first operational amplifier input follower is connected with the input end of the full-wave rectifying and proportional amplifying circuit; and the power supply of the first operational amplifier input follower is connected with the power supply voltage and grounded through the fourth capacitor and the fifth capacitor respectively.
Further, the full-wave rectifying and proportional amplifying circuit comprises a first operational amplifier, a second operational amplifier, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a fifth capacitor, a sliding rheostat, a first diode and a second diode;
the output end of the first operational amplifier input follower is connected with the third resistor; the third resistor, the fourth resistor, the fifth resistor and the sixth resistor are sequentially connected in series, and the seventh resistor is connected in parallel with the fourth resistor, the fifth resistor and the sixth resistor and then connected in series with the ninth resistor and the slide rheostat which are mutually connected in series;
the first diode and the second diode are connected in series and then connected in parallel with the fifth resistor; the negative input end of the first operational amplifier is connected with the negative electrode of the first diode and is connected between the fourth resistor and the fifth resistor; the positive input end of the first operational amplifier is grounded through the eighth resistor; the output end of the first operational amplifier is connected between the cathode of the second diode and the anode of the first diode;
one end of the fifth capacitor is connected between the seventh resistor and the ninth resistor, and the other end of the fifth capacitor is connected with the sliding end of the sliding rheostat;
the negative input end of the second operational amplifier is connected with one end of the ninth resistor, the positive input end of the second operational amplifier is grounded through the tenth resistor, the output end of the second operational amplifier is connected with the sliding end of the sliding rheostat, and the output end of the second operational amplifier is connected with the control circuit and outputs amplified direct current signals.
Further, the filter circuit further comprises a post-stage filter circuit; the input end of the post-stage filter circuit is connected with the output end of the second operational amplifier;
the rear-stage filter circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor, a sixth capacitor and a second operational amplifier follower;
the output end of the second operational amplifier is connected with the eleventh resistor, and the eleventh resistor is connected with the twelfth resistor in series and then is connected with the positive input end of the second operational amplifier follower; one end of the sixth capacitor is connected between the eleventh resistor and the twelfth resistor, and the other end of the sixth capacitor is grounded; the negative input end of the second operational amplifier follower is connected with the output end; and the thirteenth resistor is connected with the output end of the second operational amplifier follower and then outputs the amplified direct current signal.
Further, the post-stage filter circuit further comprises a seventh capacitor, a third diode and a fourth diode; the third diode is connected in series with the fourth diode, the positive electrode of the fourth diode is grounded, and the negative electrode of the third diode is connected with a power supply voltage; and the thirteenth resistor is connected between the third diode and the fourth diode and then outputs an amplified direct current signal, and the third diode and the fourth diode are grounded through the seventh capacitor.
Further, the power supply control circuit comprises a fourteenth resistor, a fifteenth resistor, a triode, a relay and a fifth diode; the output end of the MCU circuit is connected with the fourteenth resistor, and one ends of the fourteenth resistor and the fifteenth resistor are connected with the base electrode end of the triode; the other end of the fifteenth resistor is connected with the emitter of the triode and grounded; the collector of the triode is connected with the first end of the relay, and the second end of the relay is connected with a power supply voltage; the negative electrode of the fifth diode is connected with the power supply voltage, and the positive electrode of the fifth diode is connected with the first end of the relay; the relay controls the on-off of the power supply control circuit.
Further, the MCU circuit comprises a singlechip, the singlechip is provided with an ADC input end and a RELAY output end, the ADC input end is connected with the amplified direct current signal, and the RELAY output end is connected with the input end of the power supply control circuit.
Compared with the prior art, the utility model has at least the following beneficial effects:
collecting an electric signal through a sampling circuit, performing transient suppression and RC (resistance capacitance) filtering on the electric signal, transmitting the electric signal to a full-wave rectifying and proportional amplifying circuit, performing full-wave rectifying on a current signal, amplifying the current signal, and transmitting an amplified direct current signal to a control circuit; MCU circuit in the control circuit controls the break-make of power supply control circuit according to the direct current signal after amplifying, through gathering output voltage value and load current value and upper threshold, lower limit threshold and overload threshold carry out the comparison, realizes carrying out spark, short circuit and overload protection simultaneously, need not to establish other circuits in addition, has reduced the cost of circuit manufacture.
Furthermore, the discrete values are led out from the ADC input end of the singlechip peripheral equipment and compared with different thresholds, and the high-voltage power supply under different protection states can be switched off only by setting the different thresholds, so that the high-voltage power supply is protected, and the aim of simultaneously carrying out three kinds of protection is fulfilled.
Drawings
FIG. 1 is a circuit diagram of an overload protection circuit according to an embodiment of the present utility model;
fig. 2 is a circuit diagram of a short-circuit protection circuit and a spark protection circuit according to an embodiment of the present utility model.
Detailed Description
The protection circuit of the present utility model will be described in more detail below in conjunction with the schematic drawings, in which preferred embodiments of the present utility model are shown, it being understood that one skilled in the art can modify the utility model described herein while still achieving the advantageous effects of the utility model. Accordingly, the following description is to be construed as broadly known to those skilled in the art and not as limiting the utility model.
The utility model is more particularly described by way of example in the following paragraphs with reference to the drawings. Advantages and features of the utility model will become more apparent from the following description and from the claims. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the utility model.
Referring to fig. 1, the present utility model provides a protection circuit, which includes a sampling circuit, a pre-stage filter circuit, a full-wave rectifying and proportional amplifying circuit, and a control circuit.
The sampling circuit is used for collecting electric signals; so that the collected electric signals can be compared with a threshold value to judge whether short circuit, overload and the like exist. Specifically, the sampling circuit comprises a first high-voltage resistor; the high-voltage resistor R16 is a high-voltage glass glaze resistor; the sampling circuit collects the electric signals of the high-voltage resistor. The sampling circuit further comprises a first resistor R1, and the high-voltage resistor R16 and the first resistor R1 are connected in series and then grounded.
In this embodiment, the pre-stage filtering circuit performs transient suppression and RC filtering on the electric signal, and then transfers the electric signal to the full-wave rectifying and proportional amplifying circuit.
Specifically, the pre-stage filter circuit includes a diac D1, a first op-amp input follower U1A, a second resistor R2, a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4.
The two ends of the diac D1 are connected in parallel with the two ends of the first capacitor C1, the first capacitor C1 is connected in parallel with the second capacitor C2, one ends of the first capacitor C1 and the second capacitor C2 are grounded, and the second resistor R2 is connected between the other ends; the second resistor R2 is connected with the positive input end of the first operational amplifier input follower U1A, the negative input end of the first operational amplifier input follower U1A is connected with the output end of the first operational amplifier input follower U1A, and the output end of the first operational amplifier input follower U1A is connected with the input end of the full-wave rectifying and proportional amplifying circuit; the power supply of the first operational amplifier input follower U1A is connected with the power supply voltage and grounded through the fourth capacitor C4 and the third capacitor C3 respectively.
The bidirectional trigger diode D1 of the pre-stage filter circuit is used for performing transient suppression on the electric signal, preventing damage caused by transient high-energy impact and protecting circuit elements; the RC filter formed by the second resistor R2, the first capacitor C1 and the second capacitor C2 is used for carrying out RC filter on the electric signal and filtering the electric signal, so that the signal is clean and preparation is made for rectification and amplification of the electric signal.
Specifically, the diac D1 may perform transient suppression, and when the electric signal flowing through the diac D1 is too large, the diac D1 will be broken down, so that the electric signal will directly flow to the ground; further, the first op-amp input follower U1A may increase the input impedance so that the input signal is cleaner.
In this embodiment, the full-wave rectifying and proportional amplifying circuit full-wave rectifies the current signal, amplifies the dc signal, and transmits the amplified dc signal to the control circuit.
Specifically, the full-wave rectifying and proportional amplifying circuit includes a first operational amplifier U1B, a second operational amplifier U1C, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a fifth capacitor C5, a sliding resistor VR1, a first diode D2, and a second diode D3.
The output end of the first operational amplifier input follower U1A is connected with the third resistor R3; the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are sequentially connected in series, and the seventh resistor R7 is connected in parallel with the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 and then connected in series with the ninth resistor R9 and the sliding resistor VR1 which are mutually connected in series.
In addition, the first diode D2 and the second diode D3 are connected in series and then connected in parallel with the fifth resistor R5; the negative input end of the first operational amplifier U1B is connected with the negative electrode of the first diode D2 and is connected between the fourth resistor R4 and the fifth resistor R5; the positive input end of the first operational amplifier U1B is grounded through the eighth resistor R8; the output end of the first operational amplifier U1B is connected between the cathode of the second diode D3 and the anode of the first diode D2.
Further, one end of the fifth capacitor C5 is connected between the seventh resistor R7 and the ninth resistor R9, and the other end is connected to the sliding end of the sliding resistor VR 1; the negative input end of the second operational amplifier U1C is connected with one end of the ninth resistor R9, the positive input end of the second operational amplifier U1C is grounded through the tenth resistor R10, the output end of the second operational amplifier U1C is connected with the sliding end of the sliding variable resistor VR1, and the output end of the second operational amplifier U1C is connected with the control circuit and outputs amplified direct current signals.
The full-wave rectification and proportional amplification circuit is used for full-wave rectification of the electric signal to obtain a stable direct current signal, and then the proportional amplification circuit is used for amplifying the direct current signal, so that subsequent comparison judgment or other processing is facilitated, and preparation is made for comparison of the electric signal and a threshold value.
Specifically, the first diode D2, the second diode D3 and the second operational amplifier U1C perform a full-wave rectification function in the full-wave rectification and proportional amplification circuit, the first operational amplifier U1B performs an electric signal amplification function in the full-wave rectification circuit, and the sliding resistor VR1 may adjust the amplification factor of the first operational amplifier U1B.
To further filter signal noise, in a specific example, the protection circuit further includes a post-stage filter circuit; and the input end of the post-stage filter circuit is connected with the output end of the second operational amplifier U1C.
Specifically, the post-stage filter circuit comprises an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a sixth capacitor C6 and a second operational amplifier follower U1C; the output end of the second operational amplifier U1C is connected with the eleventh resistor R11, and the eleventh resistor R11 is connected with the twelfth resistor R12 in series and then is connected with the positive input end of the second operational amplifier follower U1C; one end of the sixth capacitor C6 is connected between the eleventh resistor R11 and the twelfth resistor R12, and the other end of the sixth capacitor C is grounded; the negative input end of the second operational amplifier follower U1C is connected with the output end; and the thirteenth resistor R13 is connected with the output end of the second operational amplifier follower U1C and outputs an amplified direct current signal.
Further, the post-stage filter circuit further comprises a seventh capacitor C7, a third diode D4 and a fourth diode D5; the third diode D4 is connected with the fourth diode D5 in series, the positive electrode of the fourth diode D5 is grounded, and the negative electrode of the third diode D4 is connected with a power supply voltage; the thirteenth resistor R13 is connected between the third diode D4 and the fourth diode D5, and outputs an amplified dc signal, and the third diode D4 and the fourth diode D5 are grounded through the seventh capacitor C7.
In this embodiment, after the post-stage filtering circuit is connected to the full-wave rectifying and proportional amplifying circuit, the post-stage filtering circuit filters the amplified dc signal again to obtain a cleaner electrical signal, so that in order to prepare for obtaining a more accurate discrete value by the ADC outside the single-chip microcomputer in the subsequent control circuit, the ADC is convenient to compare with a threshold value.
Specifically, the eleventh resistor R11, the twelfth resistor R12, and the second op-amp follower U1C are used for filtering. The second operational amplifier follower U1C is connected with a clamping circuit to protect the singlechip from being burnt out.
In this embodiment, the control circuit includes an MCU circuit and a power supply control circuit, where the MCU circuit controls on/off of the power supply control circuit according to the amplified dc signal.
The MCU circuit comprises a singlechip, wherein the singlechip is provided with an ADC input end and a RELAY output end, the ADC input end is connected with the amplified direct current signal, and the RELAY output end is connected with the input end of the power supply control circuit. The MCU circuit compares the ADC value with a threshold value according to the acquired ADC value, and outputs a control signal through a RELAY output end so as to control the on-off of the RELAY power supply control circuit.
Furthermore, the single chip microcomputer peripheral ADC is a 10-bit ADC value.
In addition, the power supply control circuit comprises a fourteenth resistor R14, a fifteenth resistor R15, a triode Q1, a relay K1 and a fifth diode Q5; the output end of the MCU circuit is connected with the fourteenth resistor R14, and one end of the fourteenth resistor R14 and one end of the fifteenth resistor R15 are connected with the base end of the triode Q1; the other end of the fifteenth resistor R15 is connected with the emitter of the triode Q1 and grounded; the collector electrode of the triode Q1 is connected with the first end of the relay K1, and the second end of the relay K1 is connected with a power supply voltage; the negative electrode of the fifth diode Q5 is connected with the power supply voltage, and the positive electrode of the fifth diode Q5 is connected with the first end of the relay K1; and the relay K1 controls the on-off of the power supply control circuit.
Furthermore, in another aspect of the present embodiment, an overload protection method is provided, using the protection circuit as described above, please refer to fig. 1; the overload protection method comprises the following steps:
sampling and outputting a load current value in real time through a sampling circuit;
the load current value is processed by the protection circuit, an amplified direct current signal is obtained and transmitted to the MCU circuit, and compared with an overload threshold value, and whether the acquired load current value exceeds the overload threshold value is judged;
if the overload threshold is exceeded, the MCU circuit controls the power supply control circuit to cut off a high-voltage power supply so as to realize overload protection;
and if the load current value does not exceed the overload threshold value, the high-voltage power supply supplies power normally.
Furthermore, the present embodiment also proposes a short-circuit protection method according to the protection circuit described above, that is, based on the protection circuit of fig. 1, the sampling circuit in the short-circuit protection circuit needs to add a high-voltage resistor R16 and a first resistor R1, please refer to fig. 2, and the high-voltage resistor R16 and the first resistor are connected in series and then grounded; the short-circuit protection method comprises the following steps:
converting high voltage output by a high-voltage power supply into a small voltage signal with a proportional relation through a resistor voltage division sampling method, and sampling the small voltage signal in real time through a sampling circuit to obtain an output voltage value;
comparing the output voltage value with a lower limit threshold value to determine whether to cut off a power supply;
the output voltage value is processed by the protection circuit to obtain an amplified direct current signal, the amplified direct current signal is transmitted to the MCU circuit and compared with the lower limit threshold value, and whether the acquired output voltage value is lower than the lower limit threshold value or not is judged;
if the acquired output voltage value is lower than the lower limit threshold value, the power supply control circuit cuts off the high-voltage power supply to realize short-circuit protection;
and if the acquired output voltage value is not lower than the lower limit threshold value, normally supplying power to the high-voltage power supply.
On the other hand, this embodiment also proposes a spark protection circuit according to the protection circuit described above, and the same way, that is, on the basis of the protection circuit of fig. 1, the sampling circuit in the short-circuit protection circuit needs to add a high voltage resistor R16 and a first resistor R1, please refer to fig. 2, the high voltage resistor R16 and the first resistor R1 are connected in series and then grounded, and the spark protection method includes the following steps:
converting high voltage output by a high-voltage power supply into a small voltage signal with a proportional relation through a resistor voltage division sampling method, and sampling the small voltage signal in real time through a sampling circuit to obtain an output voltage value;
comparing the output voltage value with an upper limit threshold value and a lower limit threshold value to determine whether to cut off a power supply;
the output voltage value is processed by the protection circuit to obtain an amplified direct current signal, the amplified direct current signal is transmitted to the MCU circuit and compared with the upper limit threshold value and the lower limit threshold value, and whether the acquired output voltage value exceeds the range of the upper limit threshold value and the lower limit threshold value is judged;
if the acquired output voltage value exceeds the range of the upper limit threshold value and the lower limit threshold value, the power supply control circuit cuts off the high-voltage power supply to realize the sparking protection;
and if the acquired output voltage value does not exceed the range of the upper limit threshold value and the lower limit threshold value, the high-voltage power supply supplies power normally.
Specifically, if the circuit is in overload, short circuit or ignition state, the control terminal P1 of the relay K1 is connected with the zero line;
if the circuit is in a normal working state, the control terminal P1 of the relay K1 is connected with the live wire.
In summary, the protection circuit provided in this embodiment collects an electrical signal through the sampling circuit, performs transient suppression and RC filtering on the electrical signal, then transmits the electrical signal to the full-wave rectifying and proportional amplifying circuit, performs full-wave rectification on the current signal, then amplifies the current signal, and transmits the amplified direct current signal to the control circuit; MCU circuit in the control circuit controls the break-make of power supply control circuit according to the direct current signal after amplifying, through gathering output voltage value and load current value and upper threshold, lower limit threshold and overload threshold carry out the comparison, realizes carrying out spark, short circuit and overload protection simultaneously, need not to establish other circuits in addition, has reduced the cost of circuit manufacturing, avoids causing production safety accidents such as loss of property and casualties.
Furthermore, the discrete values are led out from the ADC input end of the singlechip peripheral equipment and compared with different thresholds, and the high-voltage power supply under different protection states can be switched off only by setting the different thresholds, so that the high-voltage power supply is protected, and the aim of simultaneously carrying out three kinds of protection is fulfilled.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present utility model without departing from the spirit or scope of the utility model. Thus, it is intended that the present utility model also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
Claims (9)
1. The protection circuit is characterized by comprising a sampling circuit, a pre-stage filter circuit, a full-wave rectifying and proportional amplifying circuit and a control circuit;
the sampling circuit collects electric signals;
the pre-stage filter circuit performs transient suppression and RC filtering on the electric signal and then transmits the electric signal to the full-wave rectifying and proportional amplifying circuit;
the full-wave rectification and proportional amplification circuit is used for full-wave rectification and amplification of the electric signal and transmitting the amplified direct current signal to the control circuit;
the control circuit comprises an MCU circuit and a power supply control circuit, and the MCU circuit controls the on-off of the power supply control circuit according to the amplified direct current signal.
2. The protection circuit of claim 1, wherein the sampling circuit comprises a high voltage resistor sampling circuit; the high-voltage resistor is a high-voltage glass glaze resistor; the sampling circuit collects the electric signals of the high-voltage resistor.
3. The protection circuit of claim 2, wherein the sampling circuit further comprises a first resistor, the high voltage resistor and the first resistor being connected in series and then connected to ground.
4. The protection circuit of claim 1, wherein the pre-stage filter circuit comprises a diac, a first op-amp input follower, a second resistor, a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor;
the two ends of the diac are connected in parallel with the two ends of the first capacitor, the first capacitor is connected with the second capacitor in parallel, one ends of the first capacitor and the second capacitor are grounded, and the second resistor is connected between the other ends of the first capacitor and the second capacitor; the second resistor is connected with the positive input end of the first operational amplifier input follower, the negative input end of the first operational amplifier input follower is connected with the output end of the first operational amplifier input follower, and the output end of the first operational amplifier input follower is connected with the input end of the full-wave rectifying and proportional amplifying circuit; and the power supply of the first operational amplifier input follower is connected with the power supply voltage and grounded through the fourth capacitor and the fifth capacitor respectively.
5. The protection circuit of claim 1, wherein the full-wave rectifying and proportional amplifying circuit comprises a first operational amplifier, a second operational amplifier, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a fifth capacitor, a slide rheostat, a first diode, and a second diode;
the output end of the first operational amplifier input follower is connected with the third resistor; the third resistor, the fourth resistor, the fifth resistor and the sixth resistor are sequentially connected in series, and the seventh resistor is connected in parallel with the fourth resistor, the fifth resistor and the sixth resistor and then connected in series with the ninth resistor and the slide rheostat which are mutually connected in series;
the first diode and the second diode are connected in series and then connected in parallel with the fifth resistor; the negative input end of the first operational amplifier is connected with the negative electrode of the first diode and is connected between the fourth resistor and the fifth resistor; the positive input end of the first operational amplifier is grounded through the eighth resistor; the output end of the first operational amplifier is connected between the cathode of the second diode and the anode of the first diode;
one end of the fifth capacitor is connected between the seventh resistor and the ninth resistor, and the other end of the fifth capacitor is connected with the sliding end of the sliding rheostat;
the negative input end of the second operational amplifier is connected with one end of the ninth resistor, the positive input end of the second operational amplifier is grounded through the tenth resistor, the output end of the second operational amplifier is connected with the sliding end of the sliding rheostat, and the output end of the second operational amplifier is connected with the control circuit and outputs amplified direct current signals.
6. The protection circuit of claim 5, further comprising a post-stage filter circuit; the input end of the post-stage filter circuit is connected with the output end of the second operational amplifier;
the rear-stage filter circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor, a sixth capacitor and a second operational amplifier follower;
the output end of the second operational amplifier is connected with the eleventh resistor, and the eleventh resistor is connected with the twelfth resistor in series and then is connected with the positive input end of the second operational amplifier follower; one end of the sixth capacitor is connected between the eleventh resistor and the twelfth resistor, and the other end of the sixth capacitor is grounded; the negative input end of the second operational amplifier follower is connected with the output end; and the thirteenth resistor is connected with the output end of the second operational amplifier follower and then outputs the amplified direct current signal.
7. The protection circuit of claim 6, wherein the post-stage filter circuit further comprises a seventh capacitor, a third diode, and a fourth diode; the third diode is connected in series with the fourth diode, the positive electrode of the fourth diode is grounded, and the negative electrode of the third diode is a power supply voltage; and the thirteenth resistor is connected between the third diode and the fourth diode and then outputs an amplified direct current signal, and the third diode and the fourth diode are grounded through the seventh capacitor.
8. The protection circuit of claim 1, wherein the power control circuit comprises a fourteenth resistor, a fifteenth resistor, a triode, a relay, and a fifth diode; the output end of the MCU circuit is connected with the fourteenth resistor, and one ends of the fourteenth resistor and the fifteenth resistor are connected with the base electrode end of the triode; the other end of the fifteenth resistor is connected with the emitter of the triode and grounded; the collector of the triode is connected with the first end of the relay, and the second end of the relay is connected with a power supply voltage; the negative electrode of the fifth diode is connected with the power supply voltage, and the positive electrode of the fifth diode is connected with the first end of the relay; the relay controls the on-off of the power supply control circuit.
9. The protection circuit of claim 1, wherein the MCU circuit comprises a single-chip microcomputer having an ADC input terminal and a RELAY output terminal, the ADC input terminal being connected to the amplified dc signal, the RELAY output terminal being connected to the input terminal of the power control circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223425225.0U CN219247461U (en) | 2022-12-20 | 2022-12-20 | Protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223425225.0U CN219247461U (en) | 2022-12-20 | 2022-12-20 | Protection circuit |
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| Publication Number | Publication Date |
|---|---|
| CN219247461U true CN219247461U (en) | 2023-06-23 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202223425225.0U Active CN219247461U (en) | 2022-12-20 | 2022-12-20 | Protection circuit |
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| Country | Link |
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| CN (1) | CN219247461U (en) |
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2022
- 2022-12-20 CN CN202223425225.0U patent/CN219247461U/en active Active
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