CN109149514B - Output protection circuit and control method of power supply and building interphone - Google Patents
Output protection circuit and control method of power supply and building interphone Download PDFInfo
- Publication number
- CN109149514B CN109149514B CN201810959841.3A CN201810959841A CN109149514B CN 109149514 B CN109149514 B CN 109149514B CN 201810959841 A CN201810959841 A CN 201810959841A CN 109149514 B CN109149514 B CN 109149514B
- Authority
- CN
- China
- Prior art keywords
- analog
- voltage
- digital conversion
- digital quantity
- digital
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
- H04B1/40—Circuits
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
The invention relates to an output protection circuit of a power supply, a control method and a building interphone, comprising the following steps: the device comprises a main controller, a voltage sampling module and a switch module. The main controller is used for comparing a digital quantity difference value of the first digital quantity and the second digital quantity with a digital quantity threshold value corresponding to a preset load current, and outputting a control signal for controlling the switch module to communicate the input power supply with the external equipment when the digital quantity difference value is smaller than the digital quantity threshold value corresponding to the preset load current; and when the digital quantity difference value is greater than or equal to the digital quantity threshold value corresponding to the preset load current, outputting a control signal for controlling the switch module to disconnect the input power supply and the external equipment. Therefore, the output of the power supply can be protected through the first analog-to-digital conversion detection end and the second analog-to-digital conversion detection end of the main controller and the control logic in the main controller, the control is flexible, the application range is wide, the realization by using a large number of hardware circuits is avoided, and the hardware cost is reduced.
Description
Technical Field
The invention relates to the field of power supply output protection, in particular to an output protection circuit of a power supply, a control method of the output protection circuit of the power supply and a building interphone.
Background
At present, a power supply of an extension part of a building intercom system (namely, a building intercom) is controlled to output to supply power to external equipment (equivalent to a load), the controlled output part of the power supply generally comprises a switching tube and an overload short-circuit protection circuit, the overload short-circuit protection circuit is mainly realized through a hardware circuit, and the following schemes are mainly adopted: 1) a safety tube or a quick recovery tube is added at the power output; 2) a complex short circuit feedback circuit is used for sending a control signal to the switching tube so as to control the switching tube to be switched on and off; 3) the high-power switch tube is not used for protection, the 3 schemes are widely applicable to occasions, but the hardware cost is higher; 4) the overload short-circuit protection circuit formed by the scheme can cause large voltage fluctuation by adding the current-limiting resistor, so that the overload short-circuit protection circuit is only suitable for occasions with small current.
Disclosure of Invention
Accordingly, it is necessary to provide an output protection circuit for a power supply, a control method for the output protection circuit for a power supply, and an output protection device for a power supply, which can reduce hardware costs without depending on a hardware circuit entirely, and which can be applied to a wide range.
The utility model provides an output protection circuit of power, is applied to the building intercom, the building intercom includes intercom body and peripheral hardware, the intercom body includes main control unit and is used for giving the power output interface of peripheral hardware power supply, the circuit is used for control the power is right the power supply of peripheral hardware, its characterized in that, the circuit includes: the main controller, the voltage sampling module and the switch module;
the input end of the voltage sampling module is connected with an input power supply, the output end of the voltage sampling module is connected with the input end of the switch module, and the output end of the switch module is connected with the peripheral; the voltage sampling module is used for collecting voltage values at two sides of the voltage sampling module;
the main controller comprises a first analog-to-digital conversion detection end, a second analog-to-digital conversion detection end and an output end, the first analog-to-digital conversion detection end is connected with the input end of the voltage sampling module, the second analog-to-digital conversion detection end is connected with the output end of the voltage sampling module, and the output end of the main controller is connected with the controlled end of the switch module; the first analog-to-digital conversion detection end is used for acquiring a voltage value of one side of the voltage sampling module, which is connected with the input power supply; the second analog-to-digital conversion detection end is used for acquiring a voltage value of one side of the voltage sampling module, which is connected with the switch module;
the main controller is used for performing analog-to-digital conversion according to the voltage value acquired by the first analog-to-digital conversion detection end to obtain a first digital quantity, performing analog-to-digital conversion according to the voltage value acquired by the second analog-to-digital conversion detection end to obtain a second digital quantity, comparing a digital quantity difference value of the first digital quantity and the second digital quantity with a digital quantity threshold value corresponding to a preset load current, and outputting a control signal for communicating the input power supply with the peripheral equipment by the control switch module when the digital quantity difference value is smaller than the digital quantity threshold value; when the digital quantity difference is larger than or equal to the digital quantity threshold, outputting a control signal for controlling a switch module to disconnect the input power supply and the peripheral equipment; and the digital quantity difference value is a digital quantity corresponding to the load current in the output protection circuit.
In one embodiment, the system further comprises an anti-reverse connection module, wherein the anti-reverse connection module is connected between the switch module and the peripheral in series and used for preventing the switch module from being reversely connected.
In one embodiment, the voltage sampling module includes a sampling resistor R1.
In one embodiment, the voltage sampling module further includes a voltage dividing resistor R2, a voltage dividing resistor R3, a voltage dividing resistor R4, and a voltage dividing resistor R5, one end of the sampling resistor R1 is connected to the voltage dividing resistor R2 and the voltage dividing resistor R3 and then grounded, the other end of the sampling resistor R1 is connected to the voltage dividing resistor R4 and the voltage dividing resistor R5 and then grounded, the voltage dividing resistor R3 is connected to one end of the voltage dividing resistor R2 and connected to the first analog-to-digital conversion detection end, and the voltage dividing resistor R5 is connected to one end of the voltage dividing resistor R4 and connected to the second analog-to-digital conversion detection end.
In one embodiment, the switch module includes a resistor R8, an NPN transistor Q2, a resistor R6, a resistor R7, and a PNP transistor Q1, the resistor R8 is connected in series between the output terminal of the main controller and the base of the NPN transistor Q2, the emitter of the NPN transistor Q2 is grounded, one end of the resistor R7 is connected to the collector of the NPN transistor Q2, the other end of the resistor R7 is connected to the resistor R6 and the base of the PNP transistor Q1, the emitter of the PNP transistor Q1 and the resistor R6 are both connected to the output terminal of the voltage sampling module, and the collector of the PNP transistor Q1 is connected to the external device.
In one embodiment, the analog-to-digital conversion according to the voltage value obtained by the first analog-to-digital conversion detection end to obtain a first digital quantity satisfies a formula:
D＝V*B/Vf
wherein D is the first digital quantity, V is the voltage value obtained by the first analog-to-digital conversion detection end, B is the resolution of the analog-to-digital conversion, and V isfIs a reference voltage for analog-to-digital conversion.
In one embodiment, the reverse connection prevention module comprises a diode D1, the anode of the diode D1 is connected with the output end of the switch module, and the cathode of the diode D1 is connected with the peripheral.
In one embodiment, the main controller is further configured to output a control signal for controlling the switch module to connect the input power source and the peripheral again within a preset time after outputting a control signal for controlling the switch module to disconnect the input power source and the peripheral, so as to verify a comparison result between the digital quantity difference and the digital quantity threshold again, and the main controller includes an MCU.
On the other hand, the invention also provides a building interphone which comprises an interphone body and a peripheral, wherein the peripheral is powered by the interphone body, and the interphone body comprises the output protection circuit of the power supply in any embodiment of the embodiment.
On the other hand, the invention also provides a control method of the output protection circuit of the power supply, the output protection circuit of the power supply is applied to a building interphone, the building interphone comprises an interphone body and a peripheral device, the interphone body comprises a main controller and a power output interface for supplying power to the peripheral device, the output protection circuit of the power supply comprises the main controller, a voltage sampling module and a switch module, the voltage sampling module is used for controlling the power supply of the power supply to the peripheral device, the input end of the voltage sampling module is connected with an input power supply, the output end of the voltage sampling module is connected with the input end of the switch module, the output end of the switch module is connected with the peripheral device, the main controller comprises a first analog-to-digital conversion detection end, a second analog-to-digital conversion detection end and an output end, and the output end of the main;
the method comprises the following steps:
the voltage sampling module collects voltage values at two sides of the voltage sampling module;
the first analog-to-digital conversion detection end acquires a voltage value of one side of the voltage sampling module, which is connected with an input power supply;
the second analog-to-digital conversion detection end acquires a voltage value of one side of the voltage sampling module, which is connected with the switch module;
performing analog-to-digital conversion according to the voltage value obtained by the first analog-to-digital conversion detection end to obtain a first digital quantity;
performing analog-to-digital conversion according to the voltage value obtained by the second analog-to-digital conversion detection end to obtain a second digital quantity;
comparing the digital quantity difference value of the first digital quantity and the second digital quantity with a digital quantity threshold value corresponding to preset load current, and outputting a control signal for controlling a switch module to communicate the input power supply with the peripheral equipment if the digital quantity difference value is smaller than the digital quantity threshold value; otherwise, outputting a control signal for controlling the switch module to disconnect the input power supply and the peripheral equipment; and the digital quantity difference value is a digital quantity corresponding to the load current in the output protection circuit.
The output protection circuit of above-mentioned power is applied to the building intercom, and the building intercom includes intercom body and peripheral hardware, and the intercom body includes main control unit and is used for the power output interface for the peripheral hardware power supply, and the output protection circuit of this power is used for controlling the power supply of power supply to the peripheral hardware, includes: the device comprises a main controller, a voltage sampling module and a switch module. The main controller is used for performing analog-to-digital conversion according to the voltage value acquired by the first analog-to-digital conversion detection end to obtain a first digital quantity, performing analog-to-digital conversion according to the voltage value acquired by the second analog-to-digital conversion detection end to obtain a second digital quantity, comparing the difference value of the digital quantities of the first digital quantity and the second digital quantity with the digital quantity threshold value corresponding to the preset load current, and outputting a control signal for communicating the input power supply and the peripheral equipment by the control switch module when the difference value of the digital quantities is smaller than the digital quantity threshold value corresponding to the preset load current; and when the digital quantity difference value is greater than or equal to the digital quantity threshold value corresponding to the preset load current, outputting a control signal for controlling the switch module to disconnect the input power supply and the external equipment. Therefore, the existing main controller in the building interphone is utilized, the output of the power supply can be protected through the first analog-to-digital conversion detection end and the second analog-to-digital conversion detection end of the main controller and the control logic in the main controller, the control is flexible, the application range is wide, the realization of a large number of hardware circuits is avoided, and the hardware cost is reduced.
Drawings
FIG. 1 is a block diagram of an output protection circuit of a power supply in one embodiment;
FIG. 2 is a circuit diagram of an output protection circuit of a power supply in one embodiment;
FIG. 3 is a flow diagram of a method for controlling an output protection circuit of a power supply in one embodiment.
Detailed Description
In order that the invention may be more fully understood, reference will now be made to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
FIG. 1 is a block diagram of an output protection circuit for a power supply in one embodiment.
In this embodiment, the output protection circuit of the power supply is applied to a building interphone, the building interphone comprises an interphone body (not shown in the figure) and a peripheral (for example, a light assembly), the interphone body comprises a main controller 10 and a power output interface (not shown in the figure) for supplying power to the peripheral, the output protection circuit of the power supply is used for controlling the power supply of an input power supply to the peripheral, and the output protection circuit comprises: a main controller 10, a voltage sampling module 20 and a switch module 30.
The input end of the voltage sampling module 20 is connected with an input power supply, the output end of the voltage sampling module 20 is connected with the input end of the switch module 30, and the output end of the switch module 30 is connected with an external device. The voltage sampling module 20 is used for collecting voltage values at two sides of the voltage sampling module.
The main controller 10 includes a first analog-to-digital conversion detecting terminal (not shown), a second analog-to-digital conversion detecting terminal (not shown) and an output terminal (not shown), the first analog-to-digital conversion detecting terminal is connected to the input terminal of the voltage sampling module 20, the second analog-to-digital conversion detecting terminal is connected to the output terminal of the voltage sampling module 20, and the output terminal of the main controller 10 is connected to the controlled terminal of the switch module 30. The first analog-to-digital conversion detection end is used for acquiring the voltage value of the voltage sampling module 20 connected with the input power supply side, and the second analog-to-digital conversion detection end is used for acquiring the voltage value of the voltage sampling module 20 connected with the switch module 30 side.
The main controller 10 is configured to perform analog-to-digital (AD) conversion according to a voltage value obtained by the first analog-to-digital conversion detection end to obtain a first digital quantity, perform analog-to-digital conversion according to a voltage value obtained by the second analog-to-digital conversion detection end to obtain a second digital quantity, compare a digital quantity difference between the first digital quantity and the second digital quantity with a digital quantity threshold corresponding to a preset load current, and output a control signal for communicating an input power supply and an external device by the control switch module 30 when the digital quantity difference is smaller than the digital quantity threshold corresponding to the preset load current; when the digital quantity difference is greater than or equal to a preset digital quantity threshold corresponding to the load current, the output control switch module 30 outputs a control signal for disconnecting the input power supply from the external device, where the digital quantity difference is a digital quantity corresponding to the load current in the output protection circuit, and the preset digital quantity threshold corresponding to the load current is a digital quantity corresponding to the load current that has been set in advance. In one embodiment, the preset digital threshold corresponding to the load current is a digital value corresponding to a current value of the circuit, which is allowed to have the maximum load current, and the current value of the circuit, which is allowed to have the maximum load current, includes current values during short circuit and overload.
The output protection circuit of above-mentioned power is applied to the building intercom, and the building intercom includes intercom body and peripheral hardware, and the intercom body includes main control unit 10 and is used for the power output interface for the peripheral hardware power supply, and the output protection circuit of this power is used for controlling the power supply of power supply to the peripheral hardware, includes: a main controller 10, a voltage sampling module 20 and a switch module 30. The main controller 10 is configured to perform analog-to-digital conversion according to a voltage value obtained by the first analog-to-digital conversion detection end to obtain a first digital quantity, perform analog-to-digital conversion according to a voltage value obtained by the second analog-to-digital conversion detection end to obtain a second digital quantity, compare a digital quantity difference value between the first digital quantity and the second digital quantity with a digital quantity threshold value corresponding to a preset load current, and output a control signal for communicating an input power supply and an external device by the control switch module 30 when the digital quantity difference value is smaller than the digital quantity threshold value corresponding to the preset load current; when the digital quantity corresponding to the load current is greater than or equal to the preset digital quantity threshold corresponding to the load current, a control signal for controlling the switch module 30 to disconnect the input power supply from the external device is output. Therefore, the existing main controller 10 in the building interphone is utilized, the output of the power supply can be protected through the first analog-to-digital conversion detection end and the second analog-to-digital conversion detection end of the main controller 10 and the control logic in the main controller 10, the control is flexible, the application range is wide, the realization by using a large number of hardware circuits is avoided, and the hardware cost is reduced.
In one embodiment, the output protection circuit of the power supply further includes an anti-reverse connection module 40, and the anti-reverse connection module 40 is connected in series between the switch module 30 and the peripheral device for preventing the switch module 30 from being reversely connected.
Referring to fig. 1 and 2, in one embodiment, the voltage sampling module 20 includes a sampling resistor R1.
IN an embodiment, the voltage sampling module further includes a voltage dividing resistor R2, a voltage dividing resistor R3, a voltage dividing resistor R4, and a voltage dividing resistor R5, one end of the sampling resistor R1 is connected to the ground after being connected to the voltage dividing resistor R2 and the voltage dividing resistor R3, the other end of the sampling resistor R1 is connected to the ground after being connected to the voltage dividing resistor R4 and the voltage dividing resistor R5, the voltage dividing resistor R3 is connected to one end of the voltage dividing resistor R2 and is connected to the first analog-to-digital conversion detection terminal AD _ IN1, and the voltage dividing resistor R5 is connected to one end of the voltage dividing resistor R4 and is connected to the second analog.
In one embodiment, the reverse connection prevention module 40 includes a diode D1, an anode of the diode D1 is connected to the output terminal of the switch module 30, and a cathode of the diode D1 is connected to the peripheral devices.
IN one embodiment, the master controller 10 includes an MCU, the first analog-to-digital conversion detection terminal AD _ IN1 and the second analog-to-digital conversion detection terminal AD _ IN2 are 2 functional ports commonly used IN the MCU, and the output port PWR _ CTR L of the MCU outputs a control signal to the controlled terminal of the switch module 30 for controlling the on/off of the switch module 30, and the on/off of the switch module 30 is controlled by the 2 functional ports commonly used IN the MCU and the control logic, which is very convenient and flexible.
In one embodiment, the switch module 30 includes a resistor R8, an NPN transistor Q2, a resistor R6, a resistor R7, and a PNP transistor Q1, the resistor R8 is connected in series between the output terminal of the main controller 10 and the base of the NPN transistor Q2, the emitter of the NPN transistor Q2 is grounded, one end of the resistor R7 is connected to the collector of the NPN transistor Q2, the other end of the resistor R7 is connected to the resistor R6 and the base of the PNP transistor Q1, the emitter of the PNP transistor Q1 and the resistor R6 are both connected to the output terminal of the voltage sampling module, and the collector of the PNP transistor Q1 is connected to an external device.
With reference to fig. 2, a voltage drop is generated across the sampling resistor R1, the first analog-to-digital conversion detection terminal AD _ IN1 obtains a voltage value at one side of the input power source through the sampling resistor R1 after voltage division by the voltage dividing resistor R2 and the voltage dividing resistor R3, the second analog-to-digital conversion detection terminal AD _ IN2 obtains a voltage value at the other side of the sampling resistor R1 (i.e., at one side of the connection switch module 30) after voltage division by the voltage dividing resistor R4 and the voltage dividing resistor R5, the MCU performs analog-to-digital conversion according to the voltage value obtained at the first analog-to-digital conversion detection terminal AD _ IN1 to obtain a first digital quantity, performs analog-to-digital conversion according to the voltage value obtained at the second analog-to-digital conversion detection terminal AD _ IN2 to obtain a second digital quantity, compares the digital quantity difference between the first digital quantity and the second digital quantity with a digital quantity threshold corresponding to a preset load current, and controls only the input power source PWR _ IN a wide-output voltage range of the NPN transistor, and the PNP transistor 368.
In one embodiment, a first digital quantity obtained by performing analog-to-digital conversion according to the voltage value obtained by the first analog-to-digital conversion detection terminal (the same applies to the second digital quantity) satisfies the formula:
D＝V*B/Vf
wherein D is a first digital quantity, V is a voltage value obtained by a first analog-to-digital conversion detection end, B is the resolution of analog-to-digital conversion, and VfIs a reference voltage for analog-to-digital conversion.
In one embodiment, the first digital quantity and the second digital quantity may be obtained by using a multi-sampling averaging algorithm or other filtering algorithm, so as to improve the accuracy of the obtained first digital quantity and second digital quantity.
In one embodiment, the preset digital threshold corresponding to the load current is a digital quantity corresponding to a current value of the circuit at which the allowable load current is maximum, and can be obtained by the following formula:
ΔDmax＝ΔImax*Rf*K*B/Vf
wherein Δ Dmax is a digital threshold corresponding to a maximum current value of a load current allowed in the circuit, Δ Imax is the maximum load current allowed, Rf is a resistance value of the sampling resistor R1, K is a resistance value ratio of the voltage dividing resistor R2 and the voltage dividing resistor R3 (the resistance value ratio of the voltage dividing resistor R2 and the voltage dividing resistor R3 is equal to the resistance value ratio of the voltage dividing resistor R4 and the voltage dividing resistor R5), B is a resolution of analog-to-digital conversion, and V is a resolution of analog-to-digital conversionfIs a reference voltage for analog-to-digital conversion.
For example: the input power supply voltage is +12V, the sampling resistor R1 is 1 ohm, the voltage division ratio is 1/4, the maximum load protection current is 1A, the resolution of analog-to-digital conversion with 10-bit accuracy (i.e. 1024), and the reference voltage of analog-to-digital conversion is 5V, then the digital quantity threshold Δ Dmax corresponding to the maximum current value of the load current allowed in the circuit is:
ΔDmax＝ΔImax*Rf*K*B/Vf＝1*1*0.25*1024/5＝51.2
in one embodiment, the main controller 10 is further configured to output a control signal (e.g., a high level) for controlling the switch module 30 to connect the input power and the peripheral again within a preset time after outputting a control signal (e.g., a low level) for controlling the switch module 30 to disconnect the input power and the peripheral, so as to verify the comparison result of the digital quantity difference value and the digital quantity threshold corresponding to the preset load current again. That is, after the power source and the load are disconnected, the main controller 10 outputs a control signal (e.g., a high level) again to connect the power source and the peripheral devices within a preset time, so that the main controller 10 measures a digital quantity corresponding to the load current in the circuit again, thereby implementing the cycle detection. And if the detected digital quantity difference value is smaller than a digital quantity threshold value corresponding to the preset load current, keeping the power supply and the peripheral in a connection state. And if the detected digital quantity difference value is greater than or equal to the digital quantity threshold value corresponding to the preset load current, disconnecting the power supply and the peripheral equipment.
On the other hand, the invention also provides a building interphone, which comprises an interphone body and a peripheral, wherein the peripheral is powered by the interphone body, and the interphone body comprises the output protection circuit of the power supply in any embodiment of the embodiment.
In another aspect, the present invention further provides a control method for an output protection circuit of a power supply, where the output protection circuit of the power supply is applied to a building interphone, the building interphone includes an interphone body and a peripheral device, and the interphone body includes a main controller and a power supply output interface for supplying power to the peripheral device. The output protection circuit of the power supply comprises a main controller, a voltage sampling module and a switch module and is used for controlling the power supply of the power supply to the peripheral equipment. The input end of the voltage sampling module is connected with the input power supply, the output end of the voltage sampling module is connected with the input end of the switch module, the output end of the switch module is connected with the peripheral, the main controller comprises a first analog-to-digital conversion detection end, a second analog-to-digital conversion detection end and an output end, and the output end of the main controller is connected with the controlled end of the switch module. In one embodiment, the first analog-to-digital conversion detection terminal is connected with the input terminal of the voltage sampling module, and the second analog-to-digital conversion detection terminal is connected with the output terminal of the voltage sampling module.
The method comprises the following steps:
and S100, the voltage sampling module collects voltage values at two sides of the voltage sampling module.
S200, the first analog-to-digital conversion detection end obtains a voltage value of one side of the voltage sampling module, which is connected with the input power supply.
And S300, the second analog-to-digital conversion detection end acquires the voltage value of one side of the voltage sampling module connected with the switch module.
S400, according to the voltage value obtained by the first analog-to-digital conversion detection end, analog-to-digital conversion is carried out to obtain a first digital quantity.
And performing Analog-to-Digital (AD) conversion according to the voltage value acquired by the first AD conversion detection end to obtain a first Digital quantity. In one embodiment, the main controller performs Analog-to-Digital (AD) conversion according to the voltage value obtained by the first AD conversion detection terminal to obtain a first Digital quantity.
And S500, performing analog-to-digital conversion according to the voltage value acquired by the second analog-to-digital conversion detection end to obtain a second digital quantity.
And performing Analog-to-Digital (AD) conversion according to the voltage value acquired by the second AD conversion detection end to obtain a second Digital quantity. In one embodiment, the main controller performs Analog-to-Digital (AD) conversion according to the voltage value obtained by the second AD conversion detection terminal to obtain a second Digital quantity.
S600, judging whether the difference value of the first digital quantity and the second digital quantity is smaller than a preset digital quantity threshold value corresponding to the load current.
And comparing the digital quantity difference value of the first digital quantity and the second digital quantity with the digital quantity threshold value corresponding to the preset load current, if the digital quantity difference value is smaller than the digital quantity threshold value corresponding to the preset load current, entering the step S700, and if the digital quantity difference value is larger than or equal to the digital quantity threshold value corresponding to the preset load current, entering the step S800. And the digital quantity difference value is a digital quantity corresponding to the load current in the output protection circuit.
In one embodiment, the main controller determines whether a difference between the first digital quantity and the second digital quantity is less than a digital quantity threshold corresponding to a preset load current.
And S700, outputting a control signal for controlling the switch module to communicate the input power supply with the external equipment.
If the digital quantity difference is smaller than a digital quantity threshold corresponding to the preset load current, a control signal for communicating the input power supply and the peripheral equipment is output by the control switch module.
And S800, outputting a control signal for controlling the switch module to disconnect the input power supply and the peripheral equipment.
And if the digital quantity difference value is greater than or equal to a digital quantity threshold value corresponding to the preset load current, outputting a control signal for controlling the switch module to disconnect the input power supply and the external equipment. In one embodiment, the main controller outputs a control signal that controls the switch module to disconnect the input power source from the peripheral devices.
According to the control method of the output protection circuit of the power supply, analog-to-digital conversion is carried out according to the voltage value obtained by the first analog-to-digital conversion detection end to obtain a first digital quantity, analog-to-digital conversion is carried out according to the voltage value obtained by the second analog-to-digital conversion detection end to obtain a second digital quantity, the difference value of the digital quantities of the first digital quantity and the second digital quantity is compared with the digital quantity threshold value corresponding to the preset load current, and when the difference value of the digital quantities is smaller than the digital quantity threshold value corresponding to the preset load current, a control signal for communicating the input power supply and the peripheral equipment is output by the control switch module; and when the digital quantity difference value is greater than or equal to a digital quantity threshold value corresponding to the preset load current, outputting a control signal for controlling the switch module to disconnect the input power supply and the external equipment. Therefore, the output of the power supply can be protected through the first analog-to-digital conversion detection end, the second analog-to-digital conversion detection end and the control logic, the control is flexible, the application range is wide, the realization by using a large number of hardware circuits is avoided, and the hardware cost is reduced.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (8)
1. The utility model provides an output protection circuit of power, is applied to the building intercom, the building intercom includes intercom body and peripheral hardware, the intercom body includes main control unit and is used for giving the power output interface of peripheral hardware power supply, the circuit is used for control the power is right the power supply of peripheral hardware, its characterized in that, the circuit includes: the main controller, the voltage sampling module and the switch module;
the input end of the voltage sampling module is connected with an input power supply, the output end of the voltage sampling module is connected with the input end of the switch module, and the output end of the switch module is connected with the peripheral; the voltage sampling module is used for collecting voltage values at two sides of the voltage sampling module;
the main controller comprises a first analog-to-digital conversion detection end, a second analog-to-digital conversion detection end and an output end, the first analog-to-digital conversion detection end is connected with the input end of the voltage sampling module, the second analog-to-digital conversion detection end is connected with the output end of the voltage sampling module, and the output end of the main controller is connected with the controlled end of the switch module; the first analog-to-digital conversion detection end is used for acquiring a voltage value of one side of the voltage sampling module, which is connected with the input power supply; the second analog-to-digital conversion detection end is used for acquiring a voltage value of one side of the voltage sampling module, which is connected with the switch module;
the main controller is used for performing analog-to-digital conversion according to the voltage value acquired by the first analog-to-digital conversion detection end to obtain a first digital quantity, performing analog-to-digital conversion according to the voltage value acquired by the second analog-to-digital conversion detection end to obtain a second digital quantity, comparing a digital quantity difference value of the first digital quantity and the second digital quantity with a digital quantity threshold value corresponding to a preset load current, and outputting a control signal for communicating the input power supply with the peripheral equipment by the control switch module when the digital quantity difference value is smaller than the digital quantity threshold value; when the digital quantity difference is larger than or equal to the digital quantity threshold, outputting a control signal for controlling a switch module to disconnect the input power supply and the peripheral equipment; the digital quantity difference value is a digital quantity corresponding to the load current in the output protection circuit;
the voltage sampling module comprises a sampling resistor R1, a voltage dividing resistor R2, a voltage dividing resistor R3, a voltage dividing resistor R4 and a voltage dividing resistor R5, one end of the sampling resistor R1 is connected with the voltage dividing resistor R2 and the voltage dividing resistor R3 and then grounded, the other end of the sampling resistor R1 is connected with the voltage dividing resistor R4 and the voltage dividing resistor R5 and then grounded, the voltage dividing resistor R3 is connected with one end of the voltage dividing resistor R2 and is connected with the first analog-to-digital conversion detection end, the voltage dividing resistor R5 is connected with one end of the voltage dividing resistor R4 and is connected with the second analog-to-digital conversion detection end, and the resistance ratio of the voltage dividing resistor R2 to the voltage dividing resistor R3 is equal to the resistance ratio of the voltage dividing resistor R4 to the voltage;
the preset digital quantity threshold value corresponding to the load current is a digital quantity corresponding to a current value with the maximum load current allowed in the circuit, and is obtained through the following formula:
ΔDmax＝ΔImax*Rf*K*B/Vf
wherein Δ Dmax is a digital threshold corresponding to a maximum current value of a load current allowed in the circuit, Δ Imax is the maximum load current allowed, Rf is a resistance value of the sampling resistor R1, K is a resistance ratio of the voltage dividing resistor R2 and the voltage dividing resistor R3, B is a resolution of analog-to-digital conversion, V is a resolution of analog-to-digital conversion, and V is a resolution of the analog-to-digital conversionfIs a reference voltage for analog-to-digital conversion.
2. The output protection circuit of claim 1, further comprising a reverse connection prevention module connected in series between the switch module and the peripheral device for preventing reverse connection of the switch module.
3. The output protection circuit of claim 1, wherein the switch module comprises a resistor R8, an NPN transistor Q2, a resistor R6, a resistor R7, and a PNP transistor Q1, the resistor R8 is connected in series between the output terminal of the main controller and the base of the NPN transistor Q2, the emitter of the NPN transistor Q2 is grounded, one end of the resistor R7 is connected to the collector of the NPN transistor Q2, the other end of the resistor R7 is connected to the resistor R6 and the base of the PNP transistor Q1, the emitter of the PNP transistor Q1 and the resistor R6 are both connected to the output terminal of the voltage sampling module, and the collector of the PNP transistor Q1 is connected to the peripheral device.
4. The output protection circuit of claim 1, wherein the first digital value obtained by performing the analog-to-digital conversion according to the voltage value obtained by the first analog-to-digital conversion detection terminal satisfies a formula:
D＝V*B/Vf
wherein D is the first digital quantity, V is the voltage value obtained by the first analog-to-digital conversion detection end, B is the resolution of the analog-to-digital conversion, and V isfIs a reference voltage for analog-to-digital conversion.
5. The output protection circuit of claim 2, wherein the reverse connection prevention module comprises a diode D1, an anode of the diode D1 is connected to the output terminal of the switch module, and a cathode of the diode D1 is connected to the peripheral device.
6. The output protection circuit of claim 1, wherein the main controller is further configured to output the control signal for controlling the switch module to connect the input power source and the peripheral again within a preset time after outputting the control signal for controlling the switch module to disconnect the input power source and the peripheral, so as to verify the comparison result between the digital quantity difference and the digital quantity threshold again, and the main controller comprises an MCU.
7. A building interphone comprising an interphone body and peripheral equipment powered by the interphone body, characterized in that the interphone body comprises an output protection circuit of the power supply according to any one of claims 1 to 6.
8. A control method of an output protection circuit of a power supply is characterized in that the output protection circuit of the power supply comprises a main controller, a voltage sampling module and a switch module and is used for controlling the power supply of the power supply to peripheral equipment, the input end of the voltage sampling module is connected with an input power supply, the output end of the voltage sampling module is connected with the input end of the switch module, the output end of the switch module is connected with the peripheral equipment, the main controller comprises a first analog-to-digital conversion detection end, a second analog-to-digital conversion detection end and an output end, and the output end of the main controller is connected with a controlled end of the switch module;
the method comprises the following steps:
the voltage sampling module collects voltage values at two sides of the voltage sampling module;
the first analog-to-digital conversion detection end acquires a voltage value of one side of the voltage sampling module, which is connected with an input power supply;
the second analog-to-digital conversion detection end acquires a voltage value of one side of the voltage sampling module, which is connected with the switch module;
performing analog-to-digital conversion according to the voltage value obtained by the first analog-to-digital conversion detection end to obtain a first digital quantity;
performing analog-to-digital conversion according to the voltage value obtained by the second analog-to-digital conversion detection end to obtain a second digital quantity;
comparing the digital quantity difference value of the first digital quantity and the second digital quantity with a digital quantity threshold value corresponding to preset load current, and outputting a control signal for controlling a switch module to communicate the input power supply with the peripheral equipment if the digital quantity difference value is smaller than the digital quantity threshold value; otherwise, outputting a control signal for controlling the switch module to disconnect the input power supply and the peripheral equipment; the digital quantity difference value is a digital quantity corresponding to the load current in the output protection circuit;
the voltage sampling module comprises a sampling resistor R1, a voltage dividing resistor R2, a voltage dividing resistor R3, a voltage dividing resistor R4 and a voltage dividing resistor R5, one end of the sampling resistor R1 is connected with the voltage dividing resistor R2 and the voltage dividing resistor R3 and then grounded, the other end of the sampling resistor R1 is connected with the voltage dividing resistor R4 and the voltage dividing resistor R5 and then grounded, the voltage dividing resistor R3 is connected with one end of the voltage dividing resistor R2 and is connected with the first analog-to-digital conversion detection end, the voltage dividing resistor R5 is connected with one end of the voltage dividing resistor R4 and is connected with the second analog-to-digital conversion detection end, and the resistance ratio of the voltage dividing resistor R2 to the voltage dividing resistor R3 is equal to the resistance ratio of the voltage dividing resistor R4 to the voltage;
the preset digital quantity threshold value corresponding to the load current is a digital quantity corresponding to a current value with the maximum load current allowed in the circuit, and is obtained through the following formula:
ΔDmax＝ΔImax*Rf*K*B/Vf
wherein Δ Dmax is a digital threshold corresponding to a maximum current value of a load current allowed in the circuit, Δ Imax is the maximum load current allowed, Rf is a resistance value of the sampling resistor R1, K is a resistance ratio of the voltage dividing resistor R2 and the voltage dividing resistor R3, B is a resolution of analog-to-digital conversion, V is a resolution of analog-to-digital conversion, and V is a resolution of the analog-to-digital conversionfIs a reference voltage for analog-to-digital conversion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810959841.3A CN109149514B (en) | 2018-08-21 | 2018-08-21 | Output protection circuit and control method of power supply and building interphone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810959841.3A CN109149514B (en) | 2018-08-21 | 2018-08-21 | Output protection circuit and control method of power supply and building interphone |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109149514A CN109149514A (en) | 2019-01-04 |
| CN109149514B true CN109149514B (en) | 2020-07-14 |
Family
ID=64790690
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810959841.3A Active CN109149514B (en) | 2018-08-21 | 2018-08-21 | Output protection circuit and control method of power supply and building interphone |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109149514B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114609989A (en) * | 2021-11-25 | 2022-06-10 | 浙江中控技术股份有限公司 | High-power digital quantity output device and method for detecting and protecting open circuit and short circuit |
| CN114501739A (en) * | 2021-12-30 | 2022-05-13 | 深圳市全智芯科技有限公司 | Anti-reflected light photosensitive detection circuit and lighting equipment |
| CN117175487B (en) * | 2023-11-02 | 2024-02-06 | 江苏慕林智造科技股份有限公司 | Short-circuit protection circuit, method and readable storage medium |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201690546U (en) * | 2009-11-24 | 2010-12-29 | 福建省冠林科技有限公司 | Novel visible interphone door machine capable of entering without key |
| CN104348214B (en) * | 2013-08-09 | 2019-04-12 | 惠州市吉瑞科技有限公司 | Charger and its guard method with over-voltage over-current protection |
| CN105429096B (en) * | 2015-12-18 | 2018-05-15 | 华立科技股份有限公司 | A kind of ammeter over-current protection method and current foldback circuit |
| CN106786344A (en) * | 2016-12-20 | 2017-05-31 | 乐视汽车（北京）有限公司 | Overcurrent protective device, method, system and electronic equipment |
-
2018
- 2018-08-21 CN CN201810959841.3A patent/CN109149514B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109149514A (en) | 2019-01-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109149514B (en) | Output protection circuit and control method of power supply and building interphone | |
| CN109342973B (en) | Direct current power supply input state monitoring circuit and system | |
| CN201522606U (en) | Eccentrically-arranged power supply circuit of remote sensing CCD camera | |
| CN104716631A (en) | Air conditioner controller, over-current protection circuit of air conditioner controller and sampling circuit | |
| CN115549033A (en) | Power output protection method and circuit, and related medium and program product | |
| CN100365925C (en) | Voltage booster device having voltage-suppressing circuit | |
| CN110971216B (en) | Overcurrent protection circuit | |
| CN216670106U (en) | Power switch overcurrent detection circuit and current detection circuit | |
| CN215934474U (en) | Power supply circuit and power supply | |
| CN214412262U (en) | Protection circuit, circuit board and protection system | |
| US7206403B2 (en) | Telephone terminal equipment interface circuit | |
| US4631362A (en) | Low resistance origination scan circuit | |
| CN109572436B (en) | Diagnosis system for load circuit and electric vehicle | |
| CN103186155B (en) | Digital controller with level conversion function and level conversion circuit of digital controller | |
| EP3687018A1 (en) | Dc transmission apparatus, surge control circuit and method | |
| JP2017050936A (en) | Abnormality detection circuit and charger | |
| CN217563310U (en) | Undervoltage protection circuit and power supply device | |
| CN219394413U (en) | Communication link protection circuit and communication link | |
| CN214337547U (en) | Overcurrent protection circuit, high-side switch and vehicle-mounted automobile electronic device | |
| CN216851750U (en) | Parallel power supply protection circuit and electronic equipment | |
| CN115833046B (en) | Fault overvoltage protection circuit, transceiver chip and transceiver of CAN bus | |
| CN104160602A (en) | Method for remote control of a power converter module and a device therefor | |
| CN107181304B (en) | Charging protection circuit and automobile | |
| CN220382790U (en) | Intelligent charging control circuit and electronic equipment | |
| CN217508568U (en) | Dummy load device and power supply system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |