Misconnection voltage protection circuit applied to temperature and humidity controller

Abstract

The utility model discloses a misconnection voltage protection circuit applied to a temperature and humidity controller. The misconnection voltage protection circuit comprises a step-down circuit, a voltage detection circuit and a power supply circuit, the output end of the step-down circuit is connected to the voltage detection circuit and used for providing input voltage, the voltage detection circuit sets an alarm prompt according to the input voltage, and the output end of the step-down circuit is further connected to the power supply circuit and used for providing power supply voltage. And the power supply circuit is used for converting the power supply voltage into VDD voltage to provide a power supply for the control loop. According to the utility model, the control protection of rear-end equipment is safer, the wrong connection condition is prompted in time, the cost is lower, and the space and the equipment are small and convenient.

Description

TECHNICAL FIELD

[0001] The utility model relates to temperature and humidity controller, concretely is a kind of wrong voltage protection circuit applied to temperature and humidity controller. BACKGROUND

[0002] Temperature and humidity controller is in electric power system, complete low-temperature environment under the automatic heating equipment.For indoor high-voltage distribution device and high-voltage switch operating mechanism box in etc. Low-temperature automatic heating occasions.Electric power equipment power supply standard is three-phase four-wire system, power input general is fire zero line 220v power supply.Actual application occasion will appear three-phase fault and intermediate point misconnection problem, influence the safe operation of electric equipment.Existing product is more dependent on overvoltage overcurrent protection device truncation, space is occupied by relying on using external equipment.

[0003] Disadvantages:

[0004] 1.the overvoltage overcurrent protection device of existing volume is larger, and control protection needs external space

[0005] 2.collection mode limit, and the judgment limit based on voltage, current factor is fixed.

[0006] 3.higher cost of additional purchase overvoltage overcurrent protection device. INVENTION CONTENT

[0007] To solve the defects of the above prior art, the utility model provides a wrong voltage protection circuit applied to temperature and humidity controller, the control protection of the rear-end equipment of the utility model is safer, the cost is lower, and the space and equipment are small and convenient.

[0008] To realize the above technical purpose, the utility model adopts the following technical scheme: a wrong voltage protection circuit applied to temperature and humidity controller, including buck circuit, voltage detection circuit, power supply circuit;The output end of the buck circuit is connected to the voltage detection circuit for providing input voltage, the voltage detection circuit sets alarm prompt according to the input voltage, the output end of the buck circuit is also connected to the power supply circuit for providing power supply voltage, and the power supply circuit is used to convert the power supply voltage into VDD voltage to provide power supply for control loop.

[0009] The buck circuit includes buck chip D1, the 1 pin of buck chip D1 is connected with resistor R51, the 2 pin of buck chip D1 is connected with resistor R52, resistor R51 and resistor R52 are connected with pressure-sensitive resistor VD1, resistor R51 is connected with fuse F2, resistor R52 is connected with fuse F1, fuse F2 is connected with AcN, and fuse F1 is connected with AcL;The 3 pin of buck chip D1 is connected with thermistor F3, and thermistor F3 is connected with the voltage detection circuit and the power supply circuit;The 4 pin of buck chip D1 is grounded.

[0010] The voltage detection circuit comprises an LED, a triode Q2, the base of the triode Q2 is connected with a diode D6, the collector is connected with a resistor R36 and the LED, the resistor R36 and the LED are connected in parallel and then connected with a resistor R2, the resistor R2 is connected with the output end of the power supply circuit and the emitter is grounded, the diode D6 is connected with a resistor R29, a capacitor C13 and a resistor R28 respectively, the resistor R29 and the capacitor C13 are connected in parallel and grounded, the resistor R28 is connected with a capacitor C2, an alarm circuit and the thermistor F3 of the voltage reduction circuit respectively, and the capacitor C2 is grounded.

[0011] The power supply circuit comprises a voltage reduction chip U1, the 4th pin of the voltage reduction chip U1 is connected with the thermistor F3 of the voltage reduction circuit, the 1st pin of the voltage reduction chip U1 is connected with a capacitor C3, the 2nd pin of the voltage reduction chip U1 is connected with a resistor R1 and a resistor R3 respectively, the resistor R3, the capacitor C3, the 5th pin, the 6th pin, the 7th pin and the 8th pin of the voltage reduction chip U1 are commonly connected, the resistor R1 is connected with a capacitor C4 and a diode D3 respectively, the capacitor C4 is connected with the 5th pin of the voltage reduction chip U1, the diode D3 is connected with an inductor L1, a capacitor C6, a resistor R30 and an output VDD voltage respectively, the inductor L1 is connected with the 5th pin of the voltage reduction chip U1, and the capacitor C6 and the resistor R30 are connected in parallel and grounded.

[0012] In conclusion, the utility model obtains the following technical effects:

[0013] The control protection of the rear-end equipment is safer: while reducing the voltage, the voltage fault of the power supply access end is prompted by the LED and the digital tube of the alarm circuit, the voltage fault is judged, the output equipment is protected, and the wrong connection condition is reminded in time;

[0014] The utility model is lower in cost: a small number of electronic components are used to play a protection role;

[0015] The utility model is small in space and equipment and convenient: in the case that the space condition cannot meet the protection requirement, the portable experience is better than the complicated power external relay protection equipment;

[0016] The utility model is more flexible and has a wide application range, and the on-off condition can be changed according to different voltage requirements. DRAWINGS

[0017] Figure 1 It is a voltage reduction circuit principle diagram;

[0018] Figure 2 It is a voltage detection circuit principle diagram;

[0019] Figure 3 It is a power supply circuit principle diagram. CONCRETE IMPLEMENTATION

[0020] The utility model will be further explained in detail below in combination with the drawings.

[0021] The embodiments are only an explanation of the utility model, and are not a limitation of the utility model, and a person skilled in the art can make a modification without creative contribution according to the need after reading the specification, but as long as it is within the scope of the claims of the utility model, it is protected by the patent law.

[0022] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as a limitation of the utility model.

[0023] In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more features. In the description of the utility model, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0024] In the utility model, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication or interaction relationship between two elements. For a person skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0025] In the utility model, unless otherwise specifically defined and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" of the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" of the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0026] Embodiment 1:

[0027] A wrong connection voltage protection circuit applied to a temperature and humidity controller, comprising a voltage reduction circuit, a voltage detection circuit, a power supply circuit; the output end of the voltage reduction circuit is connected to the voltage detection circuit for providing an input voltage, the voltage detection circuit sets an alarm prompt according to the input voltage, and the output end of the voltage reduction circuit is also connected to the power supply circuit for providing a power supply voltage, and the power supply circuit is used for converting the power supply voltage into a VDD voltage to provide power supply for a control loop.

[0028] Because there is three-phase power in the power distribution room, when the connection is wrong, basically 380V is connected to the 220V port, which causes various internal components to be damaged due to exceeding the bearing voltage, so it is necessary to prevent wrong connection or ensure that the product does not have problems in the case of wrong connection and can also be reminded. The circuit is realized by adopting the mode of voltage reduction and voltage synchronous collection.

[0029] Figure 1 is a voltage reduction circuit schematic diagram, Figure 2 is a voltage detection circuit schematic diagram, Figure 3 is a power supply circuit schematic diagram.

[0030] As shown in Figure 1 , the voltage reduction circuit comprises a voltage reduction chip D1, the 1 pin of the voltage reduction chip D1 is connected with a resistor R51, the 2 pin of the voltage reduction chip D1 is connected with a resistor R52, the resistor R51 and the resistor R52 are connected with a pressure sensitive resistor VD1, the resistor R51 is connected with a fuse F2, the resistor R52 is connected with a fuse F1, the fuse F2 is connected with AcN, and the fuse F1 is connected with AcL; the 3 pin of the voltage reduction chip D1 is connected with a thermistor F3, and the thermistor F3 is connected with the voltage detection circuit and the power supply circuit; and the 4 pin of the voltage reduction chip D1 is grounded.

[0031] The model of the voltage reduction chip D1 adopts LNK304DN / SOP8, the resistor R51 and the resistor R52 are used for current limiting, and the voltage reduction circuit provides voltage reduction or voltage isolation to protect the voltage of the subsequent circuit in a controllable range.

[0032] As shown in Figure 2 , the voltage detection circuit comprises an LED and a triode Q2, the base of the triode Q2 is connected with a diode D6, the collector is connected with a resistor R36 and the LED, the resistor R36 and the LED are connected with a resistor R2 in parallel, the resistor R2 is connected with the output end of the power supply circuit, and the emitter is grounded; the diode D6 is connected with a resistor R29, a capacitor C13 and a resistor R28 respectively, the resistor R29 and the capacitor C13 are connected in parallel and grounded, the resistor R28 is connected with a capacitor C2, an alarm circuit and the thermistor F3 of the voltage reduction circuit respectively, and the capacitor C2 is grounded.

[0033] R2, R36 are voltage dividing resistors, the indicator LED is used for reminding warning, Q2 is used as a conducting switch for lighting the LED, D6 is used for preventing reverse, R29 and C13 are used for rectification filtering, the voltage detection circuit sets the alarm prompt according to the input voltage of the voltage reduction circuit, for example, the alarm voltages corresponding to the input voltages of 380V and 220V respectively, the resistor R28 receives the input voltage from the output of the voltage reduction circuit, when the input voltage exceeds the set voltage, Q2 is turned on, the LED is lighted to indicate that there is a fault, at the same time, R36 is connected to the MCU and the alarm circuit, the NMD displays the corresponding fault symbol, prompting the fault type.

[0034] As shown in Figure 3 The power supply circuit comprises a voltage reduction chip U1, the 4-pin of the voltage reduction chip U1 is connected with the thermistor F3 of the voltage reduction circuit, the 1-pin of the voltage reduction chip U1 is connected with the capacitor C3, the 2-pin of the voltage reduction chip U1 is connected with the resistor R1 and the resistor R3 respectively, the resistor R3, the capacitor C3, the 5-pin, 6-pin, 7-pin and 8-pin of the voltage reduction chip U1 are commonly connected, the resistor R1 is connected with the capacitor C4 and the diode D3 respectively, the capacitor C4 is connected with the 5-pin of the voltage reduction chip U1, the diode D3 is connected with the inductor L1, the capacitor C6, the resistor R30 and the output VDD voltage respectively, the inductor L1 is connected with the 5-pin of the voltage reduction chip U1, the capacitor C6 and the resistor R30 are connected in parallel and grounded. The 5V voltage output by the power supply circuit is used for power supply of the remaining circuits.

[0035] The voltage reduction chip U1 is LNK304D, the capacitor C3 and the resistor R3 are used for rectification filtering, the capacitor C4 and the capacitor C6 are used for filtering, the inductor L1 is used for energy storage filtering, the power supply circuit converts the AC input voltage output by the voltage reduction circuit into the DC VDD 5V voltage for power supply of the remaining circuits.

[0036] The alarm circuit is also provided, and the output end of the voltage detection circuit is connected with the MCU and the alarm circuit. The alarm circuit comprises a NMD for displaying a fault symbol.

[0037] The voltage reduction circuit divides the AC voltage, for example, 380V, into two paths, one path is used for the voltage detection circuit as an input voltage, and the other path is used for the power supply circuit as a power supply voltage, when the voltage detection circuit detects that the input voltage exceeds the range, the LED is lighted to alarm and the NMD of the alarm circuit displays the corresponding fault symbol, the power supply circuit reduces the power supply voltage into the DC 5V for power supply of the remaining circuits.

[0038] The above only describes the preferred embodiments of the present application, and does not limit the present application in any form, any simple modification, equivalent change and modification made according to the technical essence of the present application to the above embodiments are within the scope of the technical scheme of the present application.

Claims

1. A voltage protection circuit for incorrect connection applied to a temperature and humidity controller, characterized in that: Including the voltage reduction circuit, voltage detection circuit, power supply circuit, the output of voltage reduction circuit is connected to the voltage detection circuit for providing input voltage, the voltage detection circuit sets the alarm prompt according to the input voltage, the output of voltage reduction circuit is also connected to the power supply circuit for providing power supply voltage, the power supply circuit is used to convert the power supply voltage into VDD voltage for providing power supply for control loop.

2. The cross voltage protection circuit applied to the temperature and humidity controller according to claim 1, characterized in that: The voltage reduction circuit includes voltage reduction chip D1, the 1 pin of voltage reduction chip D1 is connected with resistor R51, the 2 pin of voltage reduction chip D1 is connected with resistor R52, resistor R51 and resistor R52 are connected with pressure sensitive resistor VD1, resistor R51 is connected with fuse F2, resistor R52 is connected with fuse F1, fuse F2 is connected with AcN, fuse F1 is connected with AcL, the 3 pin of voltage reduction chip D1 is connected with thermistor F3, thermistor F3 is connected with the voltage detection circuit and the power supply circuit, the 4 pin of voltage reduction chip D1 is grounded.

3. The cross voltage protection circuit for use in a temperature and humidity controller according to claim 1, wherein: The voltage detection circuit includes LED and triode Q2, the base of triode Q2 is connected with diode D6, the collector is connected with resistor R36 and LED, resistor R36 and LED are connected with resistor R2 in parallel, resistor R2 is connected with the output of power supply circuit, the emitter is grounded, diode D6 is connected with resistor R29, capacitor C13 and resistor R28 respectively, resistor R29 and capacitor C13 are connected with ground in parallel, resistor R28 is connected with capacitor C2, alarm circuit and thermistor F3 of voltage reduction circuit respectively, capacitor C2 is grounded.

4. The cross voltage protection circuit for use in a temperature and humidity controller according to claim 1, wherein: The power supply circuit includes voltage reduction chip U1, the 4 pin of voltage reduction chip U1 is connected with thermistor F3 of voltage reduction circuit, the 1 pin of voltage reduction chip U1 is connected with capacitor C3, the 2 pin of voltage reduction chip U1 is connected with resistor R1 and resistor R3 respectively, resistor R3, capacitor C3, the 5 pin, 6 pin, 7 pin and 8 pin of voltage reduction chip U1 are connected together, resistor R1 is connected with capacitor C4 and diode D3 respectively, capacitor C4 is connected with the 5 pin of voltage reduction chip U1, diode D3 is connected with inductor L1, capacitor C6, resistor R30 and output VDD voltage respectively, inductor L1 is connected with the 5 pin of voltage reduction chip U1, capacitor C6 and resistor R30 are connected with ground in parallel.

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