Portable temperature sensing alarm test tool for laboratory

Abstract

The utility model relates to a portable temperature sensing alarm test tool for a laboratory, which comprises a hollow cylindrical ceramic heating tube and a handheld shell, and a connecting seat with a heat insulation function and connected with the ceramic heating tube is arranged on the surface of one side of the shell; a battery for supplying power to the ceramic heating tube, a current-limiting resistor for limiting current and a time-limiting protection circuit for limiting the continuous operation time of the ceramic heating tube are arranged in the shell; a control switch for electrifying the ceramic heating tube is arranged on the outer surface of the shell; the testing tool can be directly operated in a handheld mode, the size can be very small, cost is low, assembling is easy, it can be guaranteed that the moving range is not limited by the wire length through the battery, the time-limited protection circuit can achieve automatic cutting-off and long-time heating, the testing tool is safer and more reliable, and the testing tool is suitable for a temperature sensing detection scene in a laboratory.

Description

Technical Field

[0001] The utility model relates to the technical field of temperature sensing alarm testing, and more specifically to a portable temperature sensing alarm testing tool for laboratories. Background Art

[0002] Point-type thermal fire detector (hereinafter referred to as "temperature sensor") is a key alarm device in the automatic fire alarm system, mainly used to detect the temperature rise caused by combustion in the early stage of a fire. This detector is designed to detect fires in a timely manner even when there is no obvious smoke. Its working principle mainly relies on thermistors to sense changes in ambient temperature. When a fire occurs, the combustion process will rapidly increase the surrounding temperature. Thermistors in the detector (such as bimetallic strips, thermistors, etc.) will change due to the rise in temperature. These changes can be physical phenomena such as expansion and changes in resistance value. When the temperature reaches or exceeds the preset threshold, the physical change of the thermistor triggers a change in the state of a switch or circuit, thereby generating an electrical signal. This electrical signal will be transmitted to the fire alarm controller. After the controller recognizes the signal, it will start the alarm system and notify relevant personnel to take action.

[0003] When testing the fire alarm function test and fire alarm control function test of the fire alarm controller, the tester needs to trigger the temperature sensor at any position on the operating frame (the temperature sensors are densely arranged on the operating frame) to send out a fire alarm signal.

[0004] There are currently two testing methods:

[0005] Method 1: Use a fire-fighting temperature gun used on professional construction sites to heat the temperature sensor to sound an alarm. This test tool has two disadvantages. First, it is expensive, with a unit price of about 300 to 500 yuan. Second, the tool is designed for use on construction sites, so the battery rod and gun head of the overall design are relatively long, which is not required in laboratory testing scenarios. Currently, the tool is not flexible and light enough when used in the laboratory.

[0006] Method 2: Use a household hair dryer to set the temperature sensor to a heating alarm. The disadvantage of this test tool is that it must be connected to a 220V power cord, which is inconvenient to move, and it makes a lot of noise during the heating process.

[0007] A portable temperature sensing alarm test tool suitable for use in a laboratory is needed to solve the problems of high cost, inflexibility and inconvenience of existing test tools, improve operational convenience and work efficiency, and save costs. Utility Model Content

[0008] The technical problem to be solved by the utility model is to provide a portable temperature sensing alarm test tool for laboratory use in view of the above-mentioned defects of the prior art.

[0009] The technical solution adopted by the utility model to solve its technical problems is:

[0010] A portable temperature sensing alarm test tool for laboratory use is constructed, which includes a hollow cylindrical ceramic heating tube and a hand-held shell, a connection seat with a heat insulation function connected to the ceramic heating tube is arranged on one side surface of the shell; a battery for powering the ceramic heating tube, a current limiting resistor for current limiting and a time-limiting protection circuit for limiting the continuous operation time of the ceramic heating tube are arranged inside the shell, and a control switch for powering the ceramic heating tube is arranged on the outer surface of the shell.

[0011] The portable temperature sensing alarm test tool for laboratory use described in the utility model, wherein the time-limited protection circuit includes a main control chip and a triode, the positive electrode of the battery, the current limiting resistor, the control switch and the ceramic heating tube are connected in series in sequence, and the negative electrode of the battery is grounded;

[0012] One end of the ceramic heating tube electrically connected to the control switch is also electrically connected to the voltage detection pin of the main control chip, and the other end of the ceramic heating tube is connected to the C pole of the transistor.

[0013] The portable temperature sensing alarm testing tool for laboratory use described in the utility model, wherein the main control chip is powered by the battery, and a voltage conversion circuit is arranged in the shell.

[0014] The portable temperature sensing alarm testing tool for laboratory use described in the utility model has a battery input of 5V, and the voltage conversion circuit is used to convert the 5V voltage into a 3.3V voltage.

[0015] The portable temperature sensing alarm testing tool for laboratory use described in the utility model has a surface temperature of 80-120 degrees when the ceramic heating tube is dry-burned.

[0016] The portable temperature sensing alarm testing tool for laboratory use described in the utility model, wherein a charging circuit board for charging the battery is arranged in the shell, and an opening corresponding to the charging interface on the charging circuit board is arranged on the outer surface of the shell.

[0017] In the portable temperature sensing alarm testing tool for laboratory use described in the utility model, the current limiting resistor and the time-limited protection circuit are both arranged on the charging circuit board.

[0018] The portable temperature sensing alarm testing tool for laboratories described in the utility model has a shell in a square shape.

[0019] The portable temperature sensing alarm testing tool for laboratory use described in the utility model, wherein the connecting seat and the control switch are located on the same side surface of the shell.

[0020] The beneficial effects of the utility model are: the test tooling applied in the present invention can be directly handheld for operation, the size can be very small, the cost is low, the assembly is simple, the battery can ensure that the moving range is not limited by the line length, and the time-limited protection circuit can automatically cut off long-term heating, making the test tooling safer and more reliable, and suitable for temperature sensing detection scenarios in laboratories. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work:

[0022] Figure 1 This is a cross-sectional view of the structure of a portable temperature sensing alarm test tool for laboratory use in a preferred embodiment of the utility model;

[0023] Figure 2 This is a circuit diagram of a portable temperature sensing alarm test tool for laboratory use in a preferred embodiment of the utility model;

[0024] Figure 3 This is a circuit diagram of a main control chip of a portable temperature sensing alarm test tool for laboratory use in a preferred embodiment of the utility model;

[0025] Figure 4 The utility model is a circuit diagram of a portable temperature sensing alarm test tool voltage conversion circuit for laboratory use according to a preferred embodiment of the utility model. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the following will be combined with the technical solution in the embodiments of the utility model for a clear and complete description. Obviously, the described embodiments are partial embodiments of the utility model, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] The portable temperature sensing alarm test tool for laboratory use in the preferred embodiment of the utility model is as follows: Figure 1 See also Figure 2-Figure 4 , comprising a hollow cylindrical ceramic heating tube 1 and a hand-held shell 2, a connection seat 3 with a heat-insulating function connected to the ceramic heating tube 1 is arranged on one side surface of the shell 2; a battery 4 for powering the ceramic heating tube 1, a current-limiting resistor R1 for current limiting, and a time-limiting protection circuit for limiting the continuous operation time of the ceramic heating tube are arranged inside the shell 2, and a control switch sw1 for powering the ceramic heating tube 1 is arranged on the outer surface of the shell 2;

[0028] The test fixture of the present application can be directly operated by hand, the size can be very small, the cost is low, the assembly is simple, the battery can ensure that the range of movement is not limited by the length of the line, and the time-limited protection circuit can automatically cut off the long-term heating, making the test fixture safer and more reliable, and suitable for temperature sensing detection scenarios in the laboratory;

[0029] Preferably, the control switch can be a jog switch or a rocker switch;

[0030] The battery uses lithium battery, lithium battery parameters: nominal voltage: 7.4V rated capacity: 2600mAh charging limit voltage: 5.2V / 2A;

[0031] Current limiting resistor parameters: about 4.6Ω (the purpose is to limit the current to about 1A);

[0032] Ceramic heating tube parameters: outer diameter 5mm inner diameter: 1.8mm, length: 70mm voltage: 3.7V, static power: 3W, dry burning surface temperature: about 100℃;

[0033] The connection seat is made of heat-insulating material or heat-insulating sheet, and the connection methods include but are not limited to bonding, threaded connection, snap-on connection, etc.;

[0034] The above parameter descriptions are only examples and are not intended to be limiting.

[0035] Preferably, the time-limited protection circuit includes a main control chip U2 and a transistor Q7, the positive electrode of the battery, the current limiting resistor R1, the control switch sw1 and the ceramic heating tube 1 are connected in series in sequence, and the negative electrode of the battery is grounded;

[0036] One end of the ceramic heating tube 1 electrically connected to the control switch sw1 is also electrically connected to the voltage detection pin (AD) of the main control chip U2, and the other end of the ceramic heating tube 1 is connected to the C pole of the transistor Q7;

[0037] The circuit principle is as follows:

[0038] When the control switch sw1 is closed, the AD pin detects the voltage, and the main control chip knows that the switch is turned on. The main control chip controls the transistor Q7 to turn on, and the ceramic heating tube is powered on for heating;

[0039] The main control chip performs timing. When the output reaches the set time, the transistor Q7 is turned off and the ceramic heating tube is powered off.

[0040] At the same time, the main control chip always detects the AD value to check whether the control switch sw1 is turned off. If it is not turned off, it will not enter the next heating cycle;

[0041] Preferably, the main control chip can adopt an sj25-i / sl single chip microcomputer (the model is only an example).

[0042] Preferably, the main control chip is powered by a battery, and a voltage conversion circuit is provided in the housing 2. Figure 4 .

[0043] Preferably, the battery input is 5V, and the voltage conversion circuit is used to convert the 5V voltage into a 3.3V voltage.

[0044] Preferably, a charging circuit board 5 for charging the battery is provided in the shell 2, and an opening 20 corresponding to the charging interface 50 on the charging circuit board 5 is provided on the outer surface of the shell 2; the current limiting resistor and the time limit protection circuit are both provided on the charging circuit board 5.

[0045] Preferably, the housing 2 is square, and the connecting seat 3 and the control switch are located on the same side surface of the housing 2, which is convenient for handheld operation.

[0046] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to the utility model.

Claims

1. A portable temperature alarm test tool for laboratory use, characterized in that: The utility model comprises a hollow cylindrical ceramic heating tube and a hand-held shell, wherein a connection seat with a heat-insulating function for connecting the ceramic heating tube is arranged on one side surface of the shell; a battery for powering the ceramic heating tube, a current-limiting resistor for current limiting, and a time-limiting protection circuit for limiting the continuous operation time of the ceramic heating tube are arranged inside the shell, and a control switch for powering the ceramic heating tube is arranged on the outer surface of the shell.

2. The portable temperature alarm test tool for laboratory use according to claim 1 is characterized in that: The time-limited protection circuit includes a main control chip and a triode, the positive electrode of the battery, the current-limiting resistor, the control switch and the ceramic heating tube are connected in series in sequence, and the negative electrode of the battery is grounded; One end of the ceramic heating tube electrically connected to the control switch is also electrically connected to the voltage detection pin of the main control chip, and the other end of the ceramic heating tube is connected to the C pole of the transistor.

3. The portable temperature alarm test tool for laboratory use according to claim 2, characterized in that: The main control chip is powered by the battery, and a voltage conversion circuit is arranged in the shell.

4. The portable temperature alarm test tool for laboratory use according to claim 3, characterized in that: The battery input is 5V, and the voltage conversion circuit is used to convert the 5V voltage into a 3.3V voltage.

5. The portable temperature sensing alarm test tool for laboratory use according to claim 1, characterized in that: The surface temperature of the ceramic heating tube is 80-120 degrees when dry-burning.

6. The portable temperature alarm test tool for laboratory use according to claim 1, characterized in that: A charging circuit board for charging the battery is arranged in the shell, and an opening corresponding to the charging interface on the charging circuit board is arranged on the outer surface of the shell.

7. The portable temperature alarm test tool for laboratory use according to claim 6, characterized in that: The current limiting resistor and the time-limiting protection circuit are both arranged on the charging circuit board.

8. The portable temperature alarm test tool for laboratory use according to claim 1, characterized in that: The shell is square.

9. The portable temperature alarm test tool for laboratory use according to claim 1, characterized in that: The connecting seat and the control switch are located on the same side surface of the housing.

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