CN2585242Y - A load overcurrent alarm device and a connector overtemperature alarm device - Google Patents

Abstract

A device mounted on a connector such as a socket, plug or patch panel capable of alerting to an overcurrent in a load and/or an overtemperature in the connector due to an overload. The load overcurrent alarm device comprises: the current detection circuit is used for detecting a signal changing along with the load current, regulating and taking out a voltage signal corresponding to the alarm current through the amplification and rectification of the amplifier, filtering the voltage signal, and controlling the comparison output circuit and the flashing and sound alarm circuit; the overtemperature alarm device of the connector comprises: the temperature detection circuit is connected with the power supply and used for detecting the temperature change of the connector and outputting the temperature change to the comparison output circuit in a voltage mode; and the comparison output circuit is used for comparing the voltage from the temperature detection circuit with a preset voltage and controlling the flashing and sound alarm circuit according to the comparison result.

Description

A load overcurrent alarm device and a connector overtemperature alarm device

technical field

The invention relates to electronic circuits, in particular to an over-current and over-temperature alarm device installed on connectors such as sockets, plugs and extension boards.

Background technique

Today, the use of electrical appliances is becoming more and more common. In daily life, many electrical appliances are often placed on one socket. Fires caused by overheating.

As an ordinary person, it is difficult to know when an appliance is shorted or overheated due to overload, especially the elderly or blind, it is impossible for them to know how many appliances are overloaded by the outlet.

Therefore, we just need a kind of electrical appliance overload alarm installed on the connectors of socket, plug or drag strip etc.

Utility model content

The problem to be solved by the utility model is to provide a device installed on connectors such as sockets, plugs or extension strips, which can alarm for load overcurrent and/or connector overtemperature caused by overload.

According to the technical problem to be solved, the utility model provides a load overcurrent alarm device, which is characterized in that it includes: a current detection circuit: composed of a transformer L1, used to detect the current change of the load and output it to the amplifier in the form of voltage Rectification, sampling filter circuit; its primary coil is a single-turn coil composed of a power line "N" connected in series with the load; signal amplification rectification, sampling filter circuit: the voltage signal from the current detection circuit is amplified, rectified, sampled and filtered and then sent to Comparison output circuit; comparison output circuit: detect the voltage from the amplification rectification and sampling filter circuit, when the output is high level, trigger the LED1 of the flash alarm circuit to flash and simultaneously trigger the sound alarm circuit to alarm; flash alarm circuit; sound Alarm circuit; manual test circuit.

According to the technical problem to be solved, the utility model also provides a connector over-temperature alarm device, which is characterized in that it includes: a temperature detection circuit: used to detect the temperature change of the connector, and output it to the comparison output in the form of voltage change circuit; comparison output circuit: used to compare the voltage from the temperature detection circuit with a predetermined voltage, thereby controlling the flash alarm circuit and the sound alarm circuit; the flash alarm circuit; the sound alarm circuit; the manual test circuit.

Because the alarm device of the present utility model can play the role of alarm (flash and sound warning) for the overcurrent and overtemperature caused by electrical overload on the connector, thereby enabling users (especially the elderly or Blind person) alert and take corrective measures in time, so as to avoid the resulting fire.

The utility model also provides: (1) the purification and protection circuit of the grid voltage, so as to prevent lightning strikes and absorb a certain range of surge pulses and high-frequency signals on the grid, and provide high-quality working power for electrical appliances; (2) manual testing The circuit can toggle the test switch to test whether the utility model is in a normal working state.

Description of drawings

Fig. 1 shows the block diagram according to the load overcurrent warning device of the present utility model;

Fig. 2 shows the block diagram according to the connector overtemperature warning device of the present utility model;

Fig. 3 specifically shows the composition of the over-current and over-temperature alarm circuit according to the preferred embodiment of the present invention.

best practice

Below, in conjunction with accompanying drawing, describe the preferred embodiment of the present utility model in detail:

First introduce the load overcurrent alarm device of the utility model: Fig. 1 shows a block diagram of the load overcurrent alarm device according to the utility model; Fig. 3 specifically shows the overcurrent alarm circuit according to the preferred embodiment of the utility model. The load overcurrent alarm device includes: a current detection circuit 11, a signal amplification and rectification, a sampling filter circuit 12, a comparison output circuit 13, a flashing alarm circuit 14 and a sound alarm circuit 15; wherein, L1 of the current detection circuit 11 is a mutual induction coil, and the power input The line "N" passes through the mutual induction coil and is connected to the "N" line of the connector, that is, the "N _OUT " terminal. The mutual induction coil can detect the load current, and it is amplified and rectified in the form of voltage, and the sampling filter circuit 12 is processed and output to the comparison output circuit 13; if the load is heavier, the current will be greater, so the voltage at both ends of the inductance L will be greater, and the C3 connected to the two ends of L1 can attenuate the high frequency; of course, it can also be used Other inductors are used to replace the mutual induction coil L1 as the current detection circuit. Adjust the output voltage of the signal amplification rectification and sampling filter circuit 12 to the voltage corresponding to the predetermined alarm current, and perform real-time detection and comparison to the comparison output circuit 13. When the load current reaches the predetermined current (such as 14A±1A), the sampling The output voltage of the circuit 12 reaches the flip high level of the comparison output circuit, so IC1A outputs a high level, and the VT1 of the flash alarm circuit 14 is turned on, so the overcurrent indicator LED1 is energized to work, flashing, and at the same time, a negative trigger sound alarm After the circuit 15 is isolated by D5, it is connected to the collector of VT1 to obtain a low level and is triggered to work. The buzzer BZ1 emits a loud alarm sound, and people can know that the electrical load at this time is too heavy (that is, over-current), and it should be adjusted immediately. . The specific structure of the signal amplification rectification and sampling filter circuit in FIG. 1 is represented by the dotted line box 12 in FIG. 3 . The circuit 12 in Fig. 3 includes: operational amplifier IC1B, C3, R2, R3, D2, RP1, C5, wherein, the positive terminal of operational amplifier IC1B is connected with mutual inductance coil L1, and its negative terminal is connected with circuit ground "N" through resistance R2 Connected, and connected to the output terminal through the resistor R3 at the same time, therefore, the voltage value obtained at the terminal 5 can be appropriately linearly amplified by properly selecting the ratio of the resistors R2 and R3. Positive terminal of the circuit 3. The circuit 13 in Fig. 1 is composed of IC1A, R5, D3, D4 to form a high-voltage output comparison circuit, wherein R5, D3, D4 form a stable reference voltage circuit, so when the voltage of the positive terminal 3 reaches a predetermined value, it will be When it is greater than the reference voltage of the negative terminal 2, IC1A outputs a high level, thereby triggering a flash and sound alarm circuit to alarm.

The comparison output circuit 13 shown in Fig. 3 and the flash alarm circuit 14 and the sound alarm circuit 15 have multiple changes, such as the circuit 13 can be replaced by the circuit 555 time base circuit as the trigger control circuit. In the circuit 555, the predetermined voltage is used to set the threshold value. When the signal is amplified and rectified, and the output voltage of the sampling filter circuit 12 exceeds the threshold value, the circuit 555 outputs a low potential. At this time, the VT1 triode is canceled, and the light-emitting diode and the sound alarm circuit are blinked. D5 of 15 is directly connected to the output terminal of the circuit 555, and the same flashing light-emitting diode emits light and the buzzer sounds an alarm. Of course, the Schmidt circuit can also be used as a comparison control circuit, and corresponding changes are made to control different alarms. device. It should be noted that any changes to boxes 13, 14, 15 of Fig. 3 according to the teachings of the present invention fall within the scope of the present invention.

In this utility model, the function of the adjustable resistor RP1 is to make the voltage of the positive terminal 3 of IC1A correspond to the predetermined alarm current through the change of the resistance value, for example, when the current is at the predetermined current 14A±1A, then through the adjustable The fine-tuning of the resistor RP1 makes the comparison output circuit output a high level, thereby triggering the alarm circuit to alarm.

Describe the function of the overtemperature alarm circuit of the present utility model below with reference to Fig. 2 and Fig. 3, wherein the connector overtemperature alarm device comprises: temperature detection circuit 21, links to each other with power + terminal and N _OUT , is used for detecting the temperature of connector Change and output to the comparison output circuit 22 in the form of voltage; the comparison output circuit 22 is used to compare the voltage from the temperature detection circuit with the predetermined voltage, when the output voltage of the sampling circuit 21 reaches the flipping low level of the comparison output circuit IC1C , so IC1C outputs a high level, and VT1 of the flash alarm circuit 23 is turned on, so the over-temperature indicator LED2 is energized to work and flashes, and at the same time, the negative trigger sound alarm circuit 15 is isolated by D6 and connected to the collector of VT2 to obtain low power When the level is triggered to work, the buzzer emits a loud alarm sound to remind people to pay attention, so as to take corrective measures in time to avoid fires caused by it.

The temperature detection circuit 21 in FIG. 3 includes resistors R8, R9, adjustable resistor RP2 and thermistor RT1 in FIG. 1, the thermistor is a negative temperature coefficient thermistor.

The comparator of the comparison control circuit 22 in Fig. 3 is that the voltage reference end 10 of the IC1C comparator is connected with the two ends of the power supply through resistors R10 and R11; the signal input end 9 of the comparator is connected with the + end of the power supply through the resistor R8, and connected with R9 connected, and connected to the negative terminal of the power supply through adjustable resistors RP2 and RT1.

When the temperature of the connector such as socket increases, the resistance value of the negative temperature coefficient thermistor RT1 decreases, and the voltage of the signal input terminal 9 of the comparator IC1C decreases, when the temperature of the connector rises to a predetermined At this time, the resistance value of the thermistor RT1 is reduced to a low resistance, and the voltage of the signal input terminal 9 of the comparator is reduced to a low potential. At this time, the comparison result of the comparator is the voltage of the signal input terminal 9 If the voltage of the reference terminal 10 is lower than the voltage of the reference terminal 10, then the output terminal 8 of the comparator outputs a high potential. After the high potential is limited by the resistor R12, the VT2 is turned on, and the blinking light-emitting diode LED2 blinks. At the same time, the sound alarm circuit 15 is isolated by the diode D6 to obtain The alarm is triggered due to low level, reminding the user to take corrective measures in time, so as to avoid the fire caused by it.

In the temperature detection circuit of this embodiment, an adjustable resistor RP2 is connected between the resistor R9 and the thermistor RT1, and its function is to fine-tune the voltage of the signal input terminal of the comparator through the change of the resistance. For example, when the temperature is at a predetermined temperature of 70±5°C, the output terminal of the comparator outputs a high potential through fine-tuning of the adjustable resistor RP2, and the LED2 flashes and emits light, simultaneously triggering the sound alarm circuit 15 to alarm. C6 connected to terminals 8 and 9 of IC1C can speed up the flipping of the comparator and stabilize the output when the temperature is at the critical alarm point.

For those skilled in the art, many changes to the comparison circuit 22 shown in FIG. 3 are obvious. For example, the comparator can be replaced by a Schmidt circuit, and of course the comparator can also be replaced by a time base circuit 555 , the peripheral circuit can be adjusted accordingly. In addition, if a positive temperature coefficient thermistor is used, the connection of the positive and negative terminals of the comparator IC1C is opposite to that shown in Figure 3. It should be noted that any changes to boxes 21, 22, 23 of Fig. 3 according to the teachings of the present invention fall within the scope of the present invention.

K1 in Figure 3 is a 3-speed single-pole toggle switch for manual testing. One end of K1 is connected to the high potential end of RT1 through J1, and the common end of K1 is connected to the negative end of the power supply through J2; the other end of K1 is connected through J3 Connected to terminal 2 of IC1A, and connected to the resistor R4 between terminal 3 of IC1A and the power supply + terminal, thus constituting the manual test circuit of the over-current alarm circuit and the over-temperature alarm circuit. When K is turned to the J1 terminal, RT1 is equivalent to Due to short circuit, if the temperature is very high, IC1C outputs a high level, the over-temperature alarm circuit is triggered, the buzzer BZ1 sounds, and LED2 flashes, indicating that the over-temperature alarm circuit 21, 22, 23, and 15 are normal; The function of R4 is to provide a positive voltage slightly higher than the negative power supply for terminal 3 of IC1B when L1 has no current induction and IC1B has no output. When K is turned to J3, terminal 2 of IC1B is pulled down to a negative potential. Then IC1B outputs a high level, the over-current alarm circuit is triggered, the buzzer BZ1 sounds, and LED1 flashes, indicating that the over-current alarm circuit 13, 14, and 15 are also normal; when K is in the middle position, the device is in normal working condition.

In the overcurrent and/or overtemperature alarm device of the present utility model, the sound alarm circuit includes: police car alarm IC2, resistors R14, R15, diodes D5, D6, NPN transistor VT3, inductor L2 and buzzer BZ1. When the NPN transistor VT1 of the over-current alarm circuit is saturated and/or the NPN transistor VT2 of the over-temperature alarm circuit is saturated, the TG1 terminal of IC2 becomes low level through the isolation of diodes D5 and D6 respectively. IC2 is thus triggered, and the police car alarm signal is output at the BD terminal. Through the amplification and resonance of the NPN transistor VT3 and the inductor L2, the buzzer BZ1 emits a loud police car alarm sound. The sound alarm circuit is shared by the over-current alarm circuit and the over-temperature alarm circuit, wherein, diodes D5 and D6 are isolation diodes, so that the over-current alarm circuit and the over-temperature alarm circuit do not interfere with each other; IC2 is a negative trigger integrated circuit.

In the overcurrent and/or overtemperature alarm device of the present invention, it also includes a grid voltage purification and protection circuit 31, including: varistors RV1, RV2, RV3, which are connected in parallel between the power supply input terminals L, N, E , used for surge protection and lightning protection; capacitor C1 is connected in parallel between the input terminals L and N of the power supply, and inhibits a certain range of high-frequency pulses.

In the over-current and/or over-temperature alarm device, it also includes a capacitor step-down rectification filter voltage regulator circuit 32: composed of capacitors C2, C4, diodes D1, R1 and voltage regulator diode ZD1, providing power to the circuit of the utility model. The device of the present invention also includes a fuse installed between the power supply terminals. When the socket is overloaded and cannot be corrected in time and the current reaches the fusing point of the fuse, the fuse is blown to implement protection.

Claims (29)

1. load overcurrent warning device is characterized in that comprising:

Current detection circuit: L1 forms by mutual inductor, and the electric current that is used to detect load changes and outputs to the form of voltage and amplifies rectification, sampling filtering circuit; The single-turn circular coil that its primary coil is formed for the power lead " N " of connecting with load;

Signal amplifies rectification, sampling filtering circuit: the voltage signal that current detection circuit is next is delivered to the comparison output circuit after amplifying rectification, sampling filtering;

Output circuit relatively: will detect from the voltage that amplifies rectification, sampling filtering circuit, when being output as high level, the LED1 of trigger flashing warning circuit is glittering and trigger the audible alarm circuit alarm simultaneously;

Flash alarm circuit;

The audible alarm circuit;

The manual test circuit.

2. device as claimed in claim 1 is characterized in that: described current detection circuit is a mutual inductor.

3. device as claimed in claim 1 is characterized in that: signal amplifies rectification, the sampling filtering circuit comprises: IC1B, capacitor C 3, C5, resistance R 2, R3, diode D2 and adjustable resistance RP1.

4. device as claimed in claim 1, it is characterized in that: relatively output circuit comprises: IC1A, R5, D3, D4, when the voltage that amplifies rectification, sampling filtering circuit from described signal reaches the upset high level, the comparer upset, IC1A exports high level, triggers described flash alarm circuit and sound warning circuit and reports to the police.

5. as claim 1 or 4 described devices, it is characterized in that: described flash alarm circuit comprises: resistance R 6, resistance R 7, NPN type triode VT1 and flicker LED 1.

6. as the described device of claim 1-4, it is characterized in that: described audible alarm circuit is public by overcurrent warning circuit and overtemperature alarm circuit.

7. as each described device among the claim 1-4, it is characterized in that: described audible alarm circuit comprises: police car chimes of doom IC2, resistance R 14, R15, diode D5, D6, triode VT3, inductance L 2 and hummer BZ1.

8. device as claimed in claim 6 is characterized in that: described police car chimes of doom IC2 is negative flip-over type integrated circuit.

9. device as claimed in claim 7 is characterized in that: described police car chimes of doom IC2 is negative flip-over type integrated circuit.

10. device as claimed in claim 7 is characterized in that: described diode D5, D6 are isolating diode, are connected to the collector of described triode VT1 and the collector of described triode VT2, so that overcurrent is reported to the police and overtemperature alarm is independent of each other.

11. as each described device among the claim 1-4, it is characterized in that: described IC1A, IC1B, IC1C are wherein three unit of integrated circuit (IC) 1:LM324.

12. device as claimed in claim 1 is characterized in that: the manual test circuit comprises: K1 is 3 grades of hilted broadsword toggle switches, and the end of K1 is connected with the hot end of RT1 by J1, and the common port of K1 is connected with power supply negative terminal by J2; The other end of K1 links to each other with the end 2 of IC1A by J3, and is connected in the end 3 of IC1A and the resistance R 4 between power supply+end, thereby constitutes the test circuit of overcurrent warning circuit and overtemperature alarm circuit.

13. as each described device among the claim 1-4; it is characterized in that: also comprise capacitance decompression rectifying and voltage-stabilizing filtering circuit; power supply is provided for described device; comprise decompression capacitor C2, discharge resistance R1, voltage stabilizing diode ZD1, commutation diode D1 and filter capacitor C4; in described device, also comprise the fuse that is installed between the power end, when the socket overload is used and be can not get correcting timely and electric current when reaching the striking point of fuse; fuse is blown, and implements protection.

14. device as claimed in claim 1 is characterized in that: comprise that also line voltage purifies and holding circuit 31, comprising: voltage dependent resistor (VDR) RV1, RV2, RV3, they are connected in parallel between power input L, N, the E, are used for surging protection and anti-lightning strike; Capacitor C 1 is connected in parallel between power input L, the N, and the high-frequency impulse of certain limit is played inhibiting effect.

15. a connector overtemperature alarm device is characterized in that comprising:

Temperature sensing circuit: be used to detect the temperature variation of connector, and export to the comparison output circuit with the form of change in voltage;

Compare output circuit: be used for the voltage from temperature sensing circuit is compared with predetermined voltage, thus control flash alarm circuit and sound warning circuit;

Flash alarm circuit;

The audible alarm circuit;

The manual test circuit.

16. device as claimed in claim 15, it is characterized in that: described temperature sensing circuit comprises: resistance R 8, resistance R 9, adjustable resistance RP2 and thermistor RT1, be used to detect the temperature variation of connector, and export to the comparison output circuit with the form of change in voltage.

17. device as claimed in claim 16, it is characterized in that: described relatively output circuit comprises: IC1C, R10, R11 and C6, be used for and compare with predetermined voltage from the voltage of temperature sensing circuit, when being elevated to predetermined value as temperature, the voltage of temperature sensing circuit output reaches the low level of the upset of IC1C, and make IC1C output high level, thereby trigger described flash alarm circuit and the warning of sound warning circuit.

18. device as claimed in claim 17 is characterized in that: described relatively output circuit also comprises: the capacitor C 6 that is parallel to end 8 and the end 9 of IC1C.

19. device as claimed in claim 17, it is characterized in that: described comparer IC1C: its reference edge 10 links to each other with both ends of power by resistance R 10, R11, and its signal input part 9 links to each other with thermistor by resistance R 9+RP2, the other end of thermistor and " N _OUT" link to each other; Its signal input part 9 also links to each other with power supply+end by R8; The output terminal 8 of described comparer links to each other with VT2 by resistance R 12.

20. device as claimed in claim 17 is characterized in that: described flash alarm circuit comprises: resistance R 12, resistance R 13, NPN type triode VT2 and sudden strain of a muscle big gun LED 2.

21. as the described device of claim 15-17, it is characterized in that: described audible alarm circuit is public by overcurrent warning circuit and overtemperature alarm circuit.

22. as each described device among the claim 15-17, it is characterized in that: described audible alarm circuit comprises: police car chimes of doom IC2, resistance R 14, R15, diode D5, D6, triode VT3, inductance L 2 and hummer BZ1.

23. device as claimed in claim 21 is characterized in that: described police car chimes of doom IC2 is negative flip-over type integrated circuit.

24. device as claimed in claim 22 is characterized in that: described police car chimes of doom IC2 is negative flip-over type integrated circuit.

25. device as claimed in claim 22 is characterized in that: described diode D5, D6 are isolating diode, are connected to the collector of described triode VT1 and the collector of described triode VT2, so that overcurrent is reported to the police and overtemperature alarm is independent of each other.

26. as each described device among the claim 15-17, it is characterized in that: described IC1A, IC1B, IC1C are wherein three unit of integrated circuit (IC) 1:LM324.

27. device as claimed in claim 15 is characterized in that: the manual test circuit comprises: K1 is 3 grades of hilted broadsword toggle switches, and the end of K1 is connected with the hot end of RT1 by J1, and the common port of K1 is connected with power supply negative terminal by J2; The other end of K1 links to each other with the end 2 of IC1A by J3, and is connected in the end 3 of IC1A and the resistance R 4 between power supply+end, thereby constitutes the test circuit of overcurrent warning circuit and overtemperature alarm circuit.

28. as each described device among the claim 15-17, it is characterized in that: also comprise capacitance decompression rectifying and voltage-stabilizing filtering circuit, power supply is provided for described device, comprises decompression capacitor C2, discharge resistance R1, voltage stabilizing diode ZD1, commutation diode D1 and filter capacitor C4.In described device, also comprise the fuse that is installed between the power end, use and can not get correcting timely and electric current when reaching the striking point of fuse when the socket overload, fuse is blown, and implements protection.

29. device as claimed in claim 15 is characterized in that: comprise that also line voltage purifies and holding circuit 31, comprising: voltage dependent resistor (VDR) RV1, RV2, RV3, they are connected in parallel between power input L, N, the E, are used for surging protection and anti-lightning strike; Capacitor C 1 is connected in parallel between power input L, the N, and the high-frequency impulse of certain limit is played inhibiting effect.

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