PTC temperature relay

Abstract

The utility model discloses a PTC (Positive Temperature Coefficient) temperature relay, which comprises an outer shell and a plurality of printed circuit boards arranged in the outer shell, the printed circuit boards are fixed through welding, and orthographic projections of the printed circuit boards are overlapped; the PTC temperature relay detection circuit is arranged on the printed circuit board; the PTC temperature relay detection circuit comprises a plurality of circuit modules, and the plurality of circuit modules are arranged on a plurality of printed circuit boards. According to the PTC temperature relay detection circuit, the plurality of circuit modules are respectively arranged on the plurality of printed circuit boards according to the difference of different functional modules in the PTC temperature relay detection circuit, and the space occupied by the circuit boards is reduced through the structural design of the circuit boards and the mutual overlapping of orthographic projections of the printed circuit boards.

Description

TECHNICAL FIELD

[0001] The utility model relates to temperature relay detection technical field especially relates to a PTC temperature relay. BACKGROUND

[0002] At present, the motor will heat in normal use, if not timely discovery and carry out certain cooling and temperature control processing, will cause the damage of motor overheating. In the prior art, the motor temperature sampling circuit is used to detect the motor temperature. The temperature relay is a kind of controller that controls circuit on-off by temperature change, plays the overheat protection of other devices on line, and is widely used in various fields. High-precision temperature relay is especially important for various devices on line, it can accurately control temperature so that line and device are not burnt and can work normally.

[0003] And PTC motor temperature detection circuit is a kind of temperature monitoring and alarm to motor temperature by detecting the resistance value change characteristics of PTC thermistor with motor temperature change. And the PTC temperature relay in the prior art has the shortcomings of large size structure, usually sets all PTC motor temperature detection circuits on a circuit board, which is not conducive to the installation and use of product, and cannot realize the miniaturization design of PTC temperature relay. UTILITY MODEL CONTENTS

[0004] Therefore, the utility model provides a kind of PTC temperature relay, the circuit board structure of PTC temperature relay is re-designed and the size of PTC temperature relay can be reduced.

[0005] The utility model adopts the following scheme to realize:

[0006] A kind of PTC temperature relay, comprising: shell body, multiple printed circuit boards being arranged in the shell body, the printed circuit board is fixed by welding between the printed circuit board, and the orthographic projection between the printed circuit board exists overlapping portion;And PTC temperature relay detection circuit being arranged on the printed circuit board;

[0007] Wherein, the PTC temperature relay detection circuit includes multiple circuit modules, and multiple circuit modules are arranged on multiple printed circuit boards.

[0008] In one embodiment, the printed circuit board includes at least: a first printed circuit board, a second printed circuit board, and a third printed circuit board; the PTC temperature relay detection circuit includes a connecting terminal; wherein the length of the first printed circuit board is greater than the length of the second printed circuit board and the third printed circuit board; the connecting terminals are respectively arranged on both sides of the first printed circuit board; an accommodating space is formed between the connecting terminals; and the second printed circuit board and the third printed circuit board are both arranged in the accommodating space.

[0009] In one embodiment, the first printed circuit board and the second printed circuit board are fixedly connected in a vertical manner, the second printed circuit board and the third printed circuit board are fixedly connected in a vertical manner, and the first printed circuit board and the third printed circuit board are arranged in parallel;

[0010] The first printed circuit board, the second printed circuit board and the third printed circuit board are in a "匚" shape or a "工" shape.

[0011] In one embodiment, the second printed circuit board is disposed at an edge of one side of the first printed circuit board, and the height of the second printed circuit board is greater than the height of the connecting terminal; the printed surface of the second printed circuit board faces the other side of the first printed circuit board, and the height of the components on the second printed circuit board is less than the width of the first printed circuit board;

[0012] The third printed circuit board is arranged on the other side of the second printed circuit board, and the third printed circuit board is located between the connecting terminals; the printed surface of the third printed circuit board faces away from the first printed circuit board.

[0013] In one embodiment, the PTC temperature relay detection circuit includes:

[0014] A power conversion circuit module, whose input end is connected to the output end of the power supply, the power conversion circuit module includes a step-down and voltage-stabilizing circuit unit, the step-down and voltage-stabilizing circuit unit is used to step down and stabilize the voltage output by the power supply and output a low-voltage DC VCC for use by the single-chip circuit module and the PTC sampling circuit module;

[0015] A PTC sampling circuit module, whose power supply end is connected to the low-voltage DC VCC, and the PTC sampling circuit module includes a PTC acquisition circuit unit, which is used to perform dual-channel temperature acquisition on the current circuit element and output dual-channel temperature differential voltage signals that can be detected and identified by the single-chip circuit module;

[0016] A single-chip computer circuit module, a signal input end of which is connected to an output end of a double-path temperature differential voltage signal of the PTC sampling circuit module, a power supply end of which is connected to the low-voltage direct current VCC, and a control signal output end of which is connected to a relay driving circuit module; the single-chip computer circuit module performs analog-digital conversion on the input temperature differential voltage signal, calculates the signal by a logic calculation unit, and then outputs a control signal to the relay driving circuit module;

[0017] A relay driving circuit module, a switch controlled end of which is connected to the control signal output end of the single-chip computer circuit module, a switch end of which is used as an alarm output end, and a power supply end of which is connected to an output end of a power supply; the relay driving circuit module comprises a relay driving circuit unit, which is used to perform a relay switch switching action according to the control signal of the single-chip computer circuit module;

[0018] An alarm indication unit, which is connected to the relay driving circuit unit and is used to indicate an over-temperature warning state of the current environment.

[0019] In an embodiment, the printed circuit board comprises at least a first printed circuit board, a second printed circuit board and a third printed circuit board; the PTC temperature relay detection circuit comprises a connection terminal; the alarm indication unit in the PTC temperature relay detection circuit is arranged on the third printed circuit board; the power supply conversion circuit module, the PTC sampling circuit module and the single-chip computer circuit module in the PTC temperature relay detection circuit are arranged on the second printed circuit board; and the relay driving circuit module in the PTC temperature relay detection circuit and the connection terminal are arranged on the first printed circuit board.

[0020] In an embodiment, the voltage reduction and stabilization circuit unit of the power supply conversion circuit module comprises a rectification unit and a voltage stabilization unit; the rectification unit is connected to both ends of an output end of a power supply; the voltage stabilization unit is connected to the rectification unit and outputs a low-voltage direct current VCC; and the other end of the voltage stabilization unit is grounded.

[0021] The rectification unit is composed of a capacitor C3, a pressure-sensitive resistor MV1 and a rectification bridge BR1 in parallel connection to form an anti-interference and anti-reverse connection power supply input structure and output a direct current;

[0022] The voltage stabilizing unit comprises a controllable three-terminal voltage regulator U2, an input resistor R1, a first adjusting resistor R2 and a second adjusting resistor R4, the input end and the output end of the controllable three-terminal voltage regulator U2 are connected between the electric nodes of the direct current output by the rectifying unit via the input resistor R1, the two ends of the first adjusting resistor R2 and the second adjusting resistor R4 connected in series are connected at the output end and the input end of the controllable three-terminal voltage regulator U2 respectively, and the middle node of the first adjusting resistor R2 and the second adjusting resistor R4 is connected to the adjusting end of the controllable three-terminal voltage regulator U2, and the low-voltage direct current VCC is output after linear voltage stabilization via the controllable three-terminal voltage regulator U2.

[0023] In one embodiment, the PTC acquisition circuit unit comprises one end of a temperature acquisition resistor PTC connected to a resistor R9, the other end of the resistor R9 connected to the low-voltage direct current VCC, the connection node V1 of the resistor R9 and the temperature acquisition resistor PTC as the first voltage signal output end of the PTC acquisition circuit unit, the connection node V1 also connected to a resistor R6; the other end of the temperature acquisition resistor PTC connected to a resistor R10, the other end of the resistor R10 connected to a resistor R11, the connection node V2 of the temperature acquisition resistor PTC and the resistor R10 as the second voltage signal output end of the PTC acquisition circuit unit, the connection node V3 of the resistor R10 and the resistor R11 as the third voltage signal output end of the PTC acquisition circuit unit; the connection node V2 also connected to a resistor R7; the connection node V2 and the connection node V3 as the output end of the two-way temperature differential voltage signal of the PTC sampling circuit module.

[0024] In one embodiment, the single-chip microcomputer circuit module comprises a single-chip microcomputer unit and its peripheral circuit, and the single-chip microcomputer unit comprises an AD conversion unit and a logic calculation unit; the signal input end of the single-chip microcomputer unit is connected to the resistor R6, the resistor R7 and the resistor R11 to receive the voltage signal of the PTC acquisition circuit unit.

[0025] In one embodiment, the relay driving circuit module comprises a relay K1 and an electronic switch tube TR1 connected in series with the relay K1 to form the relay driving circuit unit, the power supply end of the relay driving circuit unit is connected to the power supply output end, and the switch control end of the electronic switch tube TR1 is connected to the control signal output end of the single-chip microcomputer circuit module.

[0026] In one embodiment, the shell body comprises an upper cover plate and a bottom plate, a spring and a locking block are arranged below the bottom plate, and the spring and the locking block are sequentially arranged in the bottom of the bottom plate to jointly form the bottom plate part.

[0027] The PTC temperature relay further comprises a light guide column, and the printed circuit board at least comprises a first printed circuit board, a second printed circuit board and a third printed circuit board, the first printed circuit board, the second printed circuit board and the third printed circuit board are loaded from top to bottom into the bottom plate, the light guide column is arranged on the upper cover plate and constitutes a part of the upper cover plate; the part of the upper cover plate is buckled and assembled from top to bottom with the part of the bottom plate and is fixed.

[0028] The technical scheme provided by the utility model has the following technical effects:

[0029] Compared with the prior art, the difference between different functional modules in the PTC temperature relay detection circuit of the PTC temperature relay is considered, a plurality of circuit modules are arranged on a plurality of printed circuit boards, the printed circuit boards are designed in structure, the orthographic projections of the printed circuit boards are overlapped with each other, and the size of the space occupied by the printed circuit boards is reduced. According to the printed circuit board designed according to the space saving, a small-sized shell structure is further adopted to realize the small-sized design of the PTC temperature relay, and the assembly and use of the product are facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The figure is a whole circuit module diagram of an embodiment of the utility model;

[0031] Figure 2 The figure is a circuit diagram of a power conversion circuit module in the embodiment of the utility model;

[0032] Figure 3 The figure is a circuit diagram of a PTC sampling circuit module in the embodiment of the utility model;

[0033] Figure 4 The figure is a circuit diagram of a single-chip microcomputer circuit module in the embodiment of the utility model;

[0034] Figure 5 The figure is a circuit diagram of a relay driving circuit module in the embodiment of the utility model;

[0035] Figure 6 The figure is a structure schematic view of the PTC temperature relay in the embodiment of the utility model. DETAILED DESCRIPTION

[0036] To further illustrate the embodiments, the utility model provides drawings. These drawings are part of the disclosure of the utility model, mainly used to illustrate the embodiments, and can be used to explain the operation principle of the embodiments in combination with the related description of the specification. With reference to these contents, those skilled in the art should understand other possible embodiments and advantages of the utility model. The components in the drawings are not drawn according to scale, and similar component symbols are usually used to represent similar components.

[0037] The utility model is further illustrated in connection with the drawings and specific embodiments.

[0038] As Figure 1 The utility model discloses a structure diagram of one embodiment of PTC temperature relay, and the PTC temperature relay of this embodiment is used for detecting the temperature in the current circuit and carries out high temperature warning output when the temperature exceeds the preset temperature to prevent various devices on the circuit from being damaged.

[0039] The shell body, the light guide column 112, a plurality of printed circuit boards arranged in the shell body, the printed circuit boards are fixed through welding, and the orthographic projection between the printed circuit boards has an overlapping part; and a PTC temperature relay detection circuit arranged on the printed circuit board. Wherein, the PTC temperature relay detection circuit includes a plurality of modules, and according to the size of the components and the different power supply voltage requirements of each module, the plurality of modules of the PTC temperature relay detection circuit are arranged on a plurality of printed circuit boards.

[0040] In the prior art, a large printed circuit board is split into several small printed circuit boards according to the function or the size of components or the voltage and current requirements of each component, and the positions of the several small printed circuit boards are rearranged so that the orthographic projection between the printed circuit boards has an overlapping part, thereby saving the space occupied by each printed circuit board. According to the layout structure of the redesigned printed circuit board, the shell of the PTC temperature relay can be miniaturized, achieving the purpose of reducing the volume of the PTC temperature relay.

[0041] In the embodiment, the printed circuit board includes at least three printed circuit boards, namely a first printed circuit board 113, a second printed circuit board 114 and a third printed circuit board 115, the first printed circuit board 113 and the second printed circuit board 114 are fixedly connected in a vertical manner, the second printed circuit board 114 and the third printed circuit board 115 are fixedly connected in a vertical manner, and the first printed circuit board 113 and the third printed circuit board 115 are arranged in parallel. The first printed circuit board, the second printed circuit board and the third printed circuit board are arranged in a " " shape or a " " shape.

[0042] Specifically, in the embodiment, the PTC temperature relay detection circuit comprises connection terminals 120, the first printed circuit board 113 has a length greater than the lengths of the second printed circuit board 114 and the third printed circuit board 115, the two sides of the first printed circuit board 113 are respectively provided with the connection terminals 120, a containing space is formed between the connection terminals 120, and the second printed circuit board 114 and the third printed circuit board 115 are arranged in the containing space. In the PTC temperature relay provided in the embodiment, the connection terminals 120 have the largest volume, by arranging the two connection terminals 120 on the two sides of the first printed circuit board 113, and arranging other components and printed circuit boards in the middle of the two connection terminals 120, the space can be effectively saved. The second printed circuit board 114 is arranged at the edge position on one side of the first printed circuit board 113, the height of the second printed circuit board 114 is greater than the height of the connection terminal 120; the printed surface of the second printed circuit board 114 faces the other side of the first printed circuit board 113, components such as capacitors can be arranged on the second printed circuit board 114, the height of the components on the second printed circuit board 114 is less than the width of the first printed circuit board 113; the third printed circuit board 115 is arranged on the other side of the second printed circuit board 114, and the third printed circuit board 115 is located between the connection terminals 120; the printed surface of the third printed circuit board 115 faces away from the first printed circuit board 113. Among them, considering that the voltage requirements of different components are different, and various capacitors and resistors are included in the power conversion circuit in the circuit, because the height of the capacitor is relatively high, the height of the capacitor is generally not higher than the width of the connection terminal 120, therefore, the components such as capacitors can be arranged on the second printed circuit board 114, the second printed circuit board 114 is arranged vertically to the first printed circuit board 113, the maximum longitudinal height of the components on the second printed circuit board 114 is the width of the first printed circuit board 113, therefore, by concentrating the components such as capacitors on the second printed circuit board 114, the space can be further saved, and the structure of the PTC temperature relay is more compact. The third printed circuit board 115 has relatively few functions, and mainly has a display function, that is, the display components can be arranged on the third printed circuit board 115, at the same time, the third printed circuit board 115 has a small length, and can be arranged directly above the two connection terminals 120.

[0043] In this embodiment, the orthographic projection of the first printed circuit board partially or completely overlaps with the orthographic projection of the third printed circuit board. Specifically, if the first printed circuit board is positioned directly above the third printed circuit board, and the area of ​​the first printed circuit board is smaller than that of the third printed circuit board, the orthographic projection of the first printed circuit board will completely overlap with the orthographic projection of the third printed circuit board. If the area of ​​the first printed circuit board is larger than that of the third printed circuit board, the orthographic projection of the first printed circuit board will partially overlap with the orthographic projection of the third printed circuit board. If the first printed circuit board is partially positioned directly above the three printed circuit boards, i.e., the positional relationship between the first and second printed circuit boards resembles the parallel sides of a parallelogram, the orthographic projection of the first printed circuit board will partially overlap with the orthographic projection of the third printed circuit board.

[0044] like Figure 1 As shown, in this embodiment, the outer shell includes an upper cover plate 111 and a bottom plate 116. A spring 117 and a locking block 118 are provided under the bottom plate. The spring 117 and the locking block 118 are sequentially installed at the bottom of the bottom plate 116, together forming the bottom plate 116 portion. The printed circuit boards include a first printed circuit board 113, a second printed circuit board 114, and a third printed circuit board 115. The first printed circuit board 113, the second printed circuit board 114, and the third printed circuit board 115 are installed in the bottom plate 116 from top to bottom. The light guide 112 is installed on the upper cover plate 111, forming the upper cover plate 111 portion. The upper cover plate 111 portion is assembled with the bottom plate 116 portion from top to bottom to form the PTC temperature relay.

[0045] like Figure 2 As shown, in one embodiment, the PTC temperature relay detection circuit includes:

[0046] The power conversion circuit module 10 has its input connected to the output of a power supply, which provides a 24V supply voltage. The power conversion circuit module 10 includes a step-down and voltage-stabilizing circuit unit, which is used to step down and stabilize the 24V supply voltage output by the power supply and output a low-voltage DC voltage (VCC), typically 5V DC, for use by the single-chip microcomputer circuit module 20 and the PTC sampling circuit module 30. The power conversion circuit module 10 also includes a status indicator light connected in parallel to the output end. This indicator light indicates the power supply status of the output end of the power conversion circuit module 10, facilitating inspection and maintenance.

[0047] A PTC sampling circuit module 30, whose power supply end is connected to the low-voltage direct current VCC, comprises a PTC sampling circuit unit, which is used to collect two-way temperature of current circuit elements and output two-way temperature difference voltage signal capable of being detected and recognized by the single-chip microcomputer circuit module 20.

[0048] A single-chip microcomputer circuit module 20, whose signal input end is connected to the output end of the two-way temperature difference voltage signal of the PTC sampling circuit module 30, whose power supply end is connected to the low-voltage direct current VCC, and whose control signal output end is connected to the relay driving circuit module 40. The single-chip microcomputer circuit module 20 comprises a single-chip microcomputer, generally a microcontroller unit (MCU), which is integrated with a part of AD conversion function and a part of logic calculation function. The single-chip microcomputer circuit module 20 converts the input temperature difference voltage signal into analog signal through the AD conversion unit, calculates by the logic calculation unit, and then outputs control signal to the relay driving circuit module 40.

[0049] A relay driving circuit module 40, whose switch controlled end is connected to the control signal output end of the single-chip microcomputer circuit module 20, and whose switch end is used as alarm output end and can be connected to external alarm circuit module. The power supply end of the relay driving circuit module 40 is connected to the output end of power supply and is supplied by 24V voltage. The relay driving circuit module 40 comprises a relay driving circuit unit, which is used to perform relay switch switching action according to the control signal of the single-chip microcomputer circuit module 20. The relay driving circuit module 40 further comprises an alarm indication unit connected to the relay driving circuit unit, which is used to indicate the over-temperature warning state of current environment, so as to perform temperature early warning prompt.

[0050] In the embodiment, the low-voltage direct current VCC refers to power supply loop without special description, which comprises positive voltage node end and ground end.

[0051] In addition, the power conversion circuit module 10 can be replaced by other AC-DC conversion voltage reduction and voltage stabilization circuit modules, such as transformers for voltage reduction and low-voltage DC VCC output. The single-chip microcomputer of the single-chip microcomputer circuit module 20 can also use a general single-chip microcomputer chip without an AD conversion function port, but an additional AD conversion circuit needs to be connected in front of the I / O port. The single-chip microcomputer circuit module 20 performs logical operation on the acquired temperature difference voltage signal and the preset threshold temperature voltage signal, and then confirms whether the temperature of the current circuit element exceeds the preset temperature, so as to issue a high-temperature early warning signal. The temperature voltage signal logical operation of the single-chip microcomputer circuit module 20 can be realized by using a conventional detection algorithm, which is not the improvement content of the present application, and will not be described in detail here. After the alarm is output by the relay drive circuit module 40, the user can discover the abnormal situation that the temperature of the current circuit element is too high in time, and intervene in time to prevent the equipment from being damaged due to the high temperature of the element.

[0052] Referring to Figures 3 to 6 The specific circuit of each module is described as follows:

[0053] As Figure 3 As shown in one embodiment, the voltage reduction and voltage stabilization circuit unit of the power conversion circuit module 10 includes a rectification unit and a voltage stabilization unit, the output end of the power supply is tapped at both ends of the rectification unit, the voltage stabilization unit is connected to the rectification unit and outputs low-voltage DC VCC, and the other end of the voltage stabilization unit is grounded.

[0054] The rectification unit is composed of a capacitor C3, a voltage-dependent resistor MV1 and a rectifier bridge BR1 in parallel to form an anti-interference and reverse connection power input structure and output direct current; the input end of the rectification unit is 24V alternating current or 24V direct current, and one direct current output end of the rectifier bridge BR1 is connected to the voltage stabilization unit.

[0055] The input end of the voltage stabilizing unit is connected to a DC output end of the rectifier bridge BR1, for re-reducing and stabilizing the DC voltage after rectification by the rectifier unit, and outputting low-voltage DC VCC for the subsequent single-chip microcomputer circuit module 20 and PTC sampling circuit module 30. The voltage stabilizing unit comprises a controllable three-terminal voltage regulator U2 (such as model TL431), an input resistor R1 (which can also be replaced by a suitable parallel resistor group according to actual needs), a first regulating resistor R2 and a second regulating resistor R4. The input end and the output end of the controllable three-terminal voltage regulator U2 are connected between the DC voltage nodes of the rectifier unit output, i.e. between a DC output end DC-D node of the rectifier bridge BR1 and a ground node, the two ends of the series-connected first regulating resistor R2 and second regulating resistor R4 are connected to the output end and the input end of the controllable three-terminal voltage regulator U2, respectively, and the middle node of the first regulating resistor R2 and the second regulating resistor R4 with a set adjustment resistance ratio is connected to the adjustment end of the controllable three-terminal voltage regulator U2, so as to output a low-voltage DC VCC with more stable voltage after linear voltage stabilization by the controllable three-terminal voltage regulator U2, which is generally DC5V voltage, for the subsequent single-chip microcomputer circuit module 20 and PTC sampling circuit module 30.

[0056] In order to further improve the stability of the low-voltage DC VCC, the embodiment further connects a filter capacitor C4 to the input end of the voltage stabilizing unit for filter processing. Meanwhile, a capacitor C2 is connected to the output end and the input end of the controllable three-terminal voltage regulator U2.

[0057] In addition, in order to indicate the power supply state of the output end of the rectifier unit connected in the previous stage for maintenance and repair, the embodiment further comprises a state indicating lamp unit connected in parallel to the input end of the voltage stabilizing unit, which comprises a current-limiting resistor R3 and a first light-emitting diode LED1 connected in series. When the output end of the rectifier unit is in a normal power supply state, the first light-emitting diode LED1 can normally be powered to emit indicating light.

[0058] As Figure 4As shown, in one embodiment, the power input end of the PTC acquisition circuit unit is connected to the low-voltage direct current VCC. The PTC acquisition circuit unit comprises a temperature acquisition resistor PTC, one end of the temperature acquisition resistor PTC is connected to a resistor R9, the other end of the resistor R9 is connected to the low-voltage direct current VCC, the connection node V1 of the resistor R9 and the temperature acquisition resistor PTC serves as a first voltage signal output end of the PTC acquisition circuit unit, and the connection node V1 is further connected to a resistor R6. The connection node V1 of the temperature acquisition resistor PTC is further connected to a capacitor C5, and the other end of the capacitor C5 is grounded. The other end of the temperature acquisition resistor PTC is connected to a resistor R10, the other end of the resistor R10 is connected to a resistor R11, the connection node V2 of the temperature acquisition resistor PTC and the resistor R10 serves as a second voltage signal output end of the PTC acquisition circuit unit, and the connection node V3 of the resistor R10 and the resistor R11 serves as a third voltage signal output end of the PTC acquisition circuit unit. The connection node V2 is further connected to the resistor R7. The connection node V2 of the temperature acquisition resistor PTC is further connected to a capacitor C6, and the other end of the capacitor C6 is grounded. The connection node V3 of the temperature acquisition resistor PTC is further connected to a capacitor C1, and the other end of the capacitor C1 is grounded. The connection node V3 of the temperature acquisition resistor PTC is further connected to a resistor R12, and the other end of the resistor R12 is grounded. The connection node V2 and the connection node V3 are output ends of a dual-path temperature differential voltage signal of the PTC sampling circuit module 30.

[0059] The resistor R6, the resistor R7 and the resistor R11 are mainly used for current limiting, the capacitor C5 and the resistor R9 connected thereto are mainly used for voltage reduction, and the capacitor C6 and the resistor R10 are also used for voltage reduction, and the capacitor C1 and the resistor R12 are also used for voltage reduction, so as to reduce the voltage signal of the temperature acquisition resistor PTC to a suitable low-voltage sampling signal which can be recognized by the signal acquisition port (A / D conversion function port) of the single-chip microcomputer circuit module 20. Meanwhile, the connection node V2 and the connection node V3 are output ends of a dual-path temperature differential voltage signal of the PTC sampling circuit module 30, and through the dual-path sampling differential signal, signal interference can be resisted, and the signal acquisition of the single-chip microcomputer circuit module 20 is more accurate.

[0060] The PTC acquisition circuit unit of the embodiment only adopts a circuit composed of capacitors and resistors to reduce the voltage signal of the temperature acquisition resistor PTC to a suitable low-voltage sampling signal which can be recognized by the signal acquisition port of the single-chip microcomputer circuit module 20, and has the advantages of low circuit cost and stability.

[0061] As Figure 5As shown in the figure, in one embodiment, the single-chip microcomputer circuit module 20 comprises a single-chip microcomputer unit (such as a single-chip microcomputer chip of PIC121501 model) and its connected peripheral circuits (not shown in the figure) such as a reset circuit unit and a crystal unit, a signal input end of the single-chip microcomputer unit is connected to the connection node V1, the connection node V2 and the connection node V3 through the connection of the resistor R6, the resistor R7 and the resistor R11 respectively, to receive the voltage signals of the PTC collection circuit unit. The single-chip microcomputer unit is integrated with a part of AD conversion function and a part of logic calculation function, the input voltage signals of the connection node V1, the connection node V2 and the connection node V3 are converted into analog signals through the AN0\AN1\RA2 ports of the part of AD conversion function, and then calculated by the part of logic calculation function, and finally the control signal is output to the relay driving circuit module 40 through the CLKIN port.

[0062] As shown in the figure, Figure 6 As shown in the figure, in one embodiment, the relay driving circuit module 40 comprises a relay K1 and an electronic switch tube TR1 connected in series with the relay K1 to form the relay driving circuit unit, the electronic switch tube TR1 adopts a MOS tube, and in other embodiments, a triode can also be used as the electronic switch tube. The power supply end of the relay driving circuit unit is connected to the power supply output end, and is powered by a 24V voltage, and one end 1 pin of the coil driving end of the relay K1 is connected to the 24V voltage. In order to protect the circuit when the relay K1 performs the relay switch switching action, a freewheeling diode VD1 is also connected to the 1 pin and the 2 pin of the coil of the relay K1, the cathode of the freewheeling diode VD1 is connected to the 24V voltage, and the anode of the freewheeling diode VD1 is connected to the 2 pin of the coil of the relay K1. The switch controlled end of the electronic switch tube TR1 is connected to the control signal output end of the single-chip microcomputer circuit module 20. That is, the source of the electronic switch tube TR1 of the MOS tube is connected to the ground end, the 2 pin of the coil of the relay K1 is connected to the drain of the electronic switch tube TR1 of the MOS tube, and the gate of the electronic switch tube TR1 of the MOS tube is connected to the control signal output end (CLKIN port) of the single-chip microcomputer circuit module 20 as the switch controlled end, so as to perform the relay switch switching action according to the control signal of the single-chip microcomputer circuit module 20. The gate of the electronic switch tube TR1 of the MOS tube is also connected in series with the resistor R8 for current limiting.

[0063] In the embodiment, an alarm indicating unit is further connected between the gate and the source of the electronic switch tube TR1 of the MOS tube, and the alarm indicating unit is used to indicate the over-temperature warning state of the current environment. The alarm indicating unit comprises a second light emitting diode LED2 and a resistor R13 connected in series. When the switch state of the relay K1 is in the closed and conductive state, the second light emitting diode LED2 can be normally powered to emit indicating light to prompt the over-temperature warning.

[0064] In one embodiment, the printed circuit board comprises a first printed circuit board 113, a second printed circuit board 114 and a third printed circuit board 115, wherein the first printed board contains an LED indicating lamp, which can be used as a PTC resistance to light up a warning when an over-temperature point is detected. The first printed board and the second printed board are fixed by vertical welding through a solder pad. A single-chip microcomputer and a power conversion circuit are arranged on the second printed board, which are used for PTC temperature signal acquisition and processing, LED indicating lamp and relay control output. The second printed board and the third printed board are fixed by vertical welding through a solder pad. The third printed board contains a relay and a connecting terminal, which are used for node signal output.

[0065] Alternatively, different modules can be arranged on different circuit boards according to actual needs, which will not be described here.

[0066] In the embodiment, considering the difference in the supply voltage between the single-chip microcomputer circuit module 20, the PTC sampling circuit module 30 and the relay driving circuit module 40, different power supplies are used respectively, so that the circuit is more stable. Moreover, according to different voltage requirements, different circuit modules can be arranged on different circuit boards to reduce the size of the circuit board. Through the layout design of the printed circuit board, the volume of the PTC temperature relay is more compact, which can be accommodated in a relatively small shell.

[0067] Therefore, the PTC temperature relay provided in the embodiment adopts a double-layer plus side plate structure to increase the layout space, adopts a simplified circuit to realize reliable PTC temperature acquisition and alarm output, and realizes miniaturized layout. Moreover, a miniaturized shell structure is adopted to realize miniaturized design, which is beneficial to realize the assembly and use of the product.

[0068] Although the utility model is specifically shown and introduced in combination with the preferred embodiments, those skilled in the art should understand that various changes can be made to the utility model in form and detail without departing from the spirit and scope of the utility model defined in the appended claims, and all the changes are within the protection scope of the utility model.

Claims

1. A PTC temperature relay, characterized in that: Comprising: An outer housing, a plurality of printed circuit boards disposed inside the outer housing, the printed circuit boards being fixed by welding, and there being an overlapping portion in the orthographic projection between the printed circuit boards; And a PTC temperature relay detection circuit disposed on the printed circuit boards; Wherein, the PTC temperature relay detection circuit includes a plurality of circuit modules, and the plurality of circuit modules are disposed on a plurality of printed circuit boards.

2. The PTC temperature relay according to claim 1, characterized in that: The printed circuit boards at least include: a first printed circuit board, a second printed circuit board, and a third printed circuit board. The PTC temperature relay detection circuit includes connection terminals. Among them, the length of the first printed circuit board is greater than the lengths of the second printed circuit board and the third printed circuit board. The connection terminals are respectively disposed on both sides of the first printed circuit board, and a receiving space is formed between the connection terminals, and the second printed circuit board and the third printed circuit board are both disposed in the receiving space.

3. The PTC temperature relay according to claim 2, characterized in that: The first printed circuit board and the second printed circuit board are fixedly connected in a perpendicular manner, the second printed circuit board and the third printed circuit board are fixedly connected in a perpendicular manner, and the first printed circuit board and the third printed circuit board are arranged in parallel; The first printed circuit board, the second printed circuit board, and the third printed circuit board are in an "L" shape or an "I" shape.

4. The PTC temperature relay according to claim 3, characterized in that: The second printed circuit board is disposed at an edge position on one side of the first printed circuit board, and the height of the second printed circuit board is greater than the height of the connection terminals; the printed surface on the second printed circuit board faces the other side of the first printed circuit board, and the height of the components on the second printed circuit board is less than the width of the first printed circuit board; The third printed circuit board is disposed on the other side of the second printed circuit board and is located between the connection terminals; the printed surface of the third printed circuit board faces away from the first printed circuit board.

5. The PTC temperature relay according to claim 1, characterized in that: The PTC temperature relay detection circuit includes: A power conversion circuit module, whose input terminal is connected to the output terminal of a power supply. The power conversion circuit module includes a step-down and voltage stabilization circuit unit, and the step-down and voltage stabilization circuit unit is used to step down and stabilize the voltage output by the power supply and output a low-voltage direct current VCC for use by the single-chip microcomputer circuit module and the PTC sampling circuit module; A PTC sampling circuit module, whose power supply terminal is connected to the low-voltage direct current VCC. The PTC sampling circuit module includes a PTC acquisition circuit unit, and the PTC acquisition circuit unit is used to perform dual-channel temperature acquisition on the current circuit components and output a dual-channel temperature differential voltage signal that can be detected and recognized by the single-chip microcomputer circuit module; A single-chip microcomputer circuit module, whose signal input end is connected to the output end of the dual-channel temperature differential voltage signal of the PTC sampling circuit module, whose power supply end is connected to the low-voltage DC VCC, and whose control signal output end is connected to the relay drive circuit module. The single-chip microcomputer circuit module performs analog-to-electric conversion on the input temperature differential voltage signal through the AD conversion unit, and then performs calculation by the logic calculation unit, and then outputs the control signal to the relay drive circuit module; A relay drive circuit module, wherein the switch controlled end thereof is connected to the control signal output end of the single-chip microcomputer circuit module, the switch end thereof is used as an alarm output end, and the power supply end thereof is connected to the output end of the power supply. The relay drive circuit module includes a relay drive circuit unit, and the relay drive circuit unit is used to perform relay switch switching actions according to the control signal of the single-chip microcomputer circuit module; An alarm indicating unit is connected to the relay driving circuit unit, and the alarm indicating unit is used to indicate the over-temperature warning state of the current environment.

6. The PTC temperature relay according to claim 5, characterized in that: The printed circuit board includes at least: a first printed circuit board, a second printed circuit board, and a third printed circuit board. The PTC temperature relay detection circuit includes a connecting terminal. The alarm indication unit in the PTC temperature relay detection circuit is arranged on the third printed circuit board. The power conversion circuit module, the PTC sampling circuit module, and the single-chip computer circuit module in the PTC temperature relay detection circuit are arranged on the second printed circuit board. The relay drive circuit module in the PTC temperature relay detection circuit and the connecting terminal are arranged on the first printed circuit board.

7. The PTC temperature relay according to claim 5, characterized in that: The step-down and voltage-stabilizing circuit unit of the power conversion circuit module includes a rectifier unit and a voltage-stabilizing unit, wherein two ends of the rectifier unit are connected to the output end of the power supply, the voltage-stabilizing unit is connected to the rectifier unit and outputs a low-voltage DC VCC, and the other end of the voltage-stabilizing unit is grounded; The rectifier unit is composed of a capacitor C3, a varistor MV1 and a rectifier bridge BR1 connected in parallel to form an anti-interference and anti-reverse power input structure and output DC power; The voltage stabilizing unit includes: a controllable three-terminal voltage regulator U2, an input resistor R1, a first regulating resistor R2 and a second regulating resistor R4. The input and output ends of the controllable three-terminal voltage regulator U2 are connected between the electrical nodes of the direct current output by the rectifier unit via the input resistor R1. The two ends of the first regulating resistor R2 and the second regulating resistor R4 connected in series are respectively connected to the output and input ends of the controllable three-terminal voltage regulator U2. The intermediate node of the first regulating resistor R2 and the second regulating resistor R4 is connected to the adjustment end of the controllable three-terminal voltage regulator U2. The low voltage DC VCC is output after linear stabilization by the controllable three-terminal voltage regulator U2.

8. The PTC temperature relay according to claim 5, characterized in that: The PTC acquisition circuit unit includes: one end of a temperature acquisition resistor PTC is connected to a resistor R9, the other end of the resistor R9 is connected to the low voltage DC VCC, a connection node V1 between the resistor R9 and the temperature acquisition resistor PTC serves as a first voltage signal output end of the PTC acquisition circuit unit, and the connection node V1 is also connected to a resistor R6; the other end of the temperature acquisition resistor PTC is connected to a resistor R10, the other end of the resistor R10 is connected to a resistor R11, a connection node V2 between the temperature acquisition resistor PTC and the resistor R10 serves as a second voltage signal output end of the PTC acquisition circuit unit, and a connection node V3 between the resistor R10 and the resistor R11 serves as a third voltage signal output end of the PTC acquisition circuit unit; the connection node V2 is also connected to a resistor R7; the connection nodes V2 and V3 are output ends of the dual-path temperature differential voltage signal of the PTC sampling circuit module.

9. The PTC temperature relay according to claim 8, characterized in that: The single-chip circuit module includes a single-chip unit and its peripheral circuits. The single-chip unit includes an AD conversion unit and a logic calculation unit. The signal input end of the single-chip unit is connected to the resistor R6, the resistor R7, and the resistor R11 to receive the voltage signal of the PTC acquisition circuit unit.

10. The PTC temperature relay according to claim 5, characterized in that: The relay drive circuit module includes a relay K1 and an electronic switch tube TR1 connected in series with the relay K1 to form the relay drive circuit unit. The power supply end of the relay drive circuit unit is connected to the power supply output end, and the switch controlled end of the electronic switch tube TR1 is connected to the control signal output end of the single-chip circuit module.

11. The PTC temperature relay according to claim 1, characterized in that: The outer shell includes an upper cover and a bottom plate, a spring and a locking block are provided below the bottom plate, and the spring and the locking block are sequentially installed at the bottom of the bottom plate to form a bottom plate portion together; The PTC temperature relay also includes a light guide column, and the printed circuit board includes at least: a first printed circuit board, a second printed circuit board and a third printed circuit board. The first printed circuit board, the second printed circuit board and the third printed circuit board are installed in the base plate from top to bottom. The light guide column is installed on the upper cover plate and constitutes part of the upper cover plate; the upper cover plate part is assembled and fixed with the base plate part from top to bottom.

Images