System for rapidly positioning circuit temperature drift fault point

Abstract

The invention discloses a system for rapidly positioning a circuit temperature drift fault point, and the system comprises a to-be-tested device which is provided with a temperature measurement system. The temperature measurement system comprises a heat dissipation group, a TEC group, a heat conduction pad, a temperature measurement element and a temperature controller, the to-be-tested device is connected with a temperature measuring element, the TEC group is tightly pressed and connected with the to-be-tested device and the temperature measuring element at the same time through a heat conducting pad, and the heat dissipation group and the TEC group are adhered through heat conducting silicone grease; and the temperature controller is in circuit connection with a temperature measuring element, a TEC group and a power supply. According to the invention, temperature control of fixed-point heating or cooling can be carried out on a circuit by utilizing the characteristic that the TEC semiconductor cooler can be heated and cooled.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit temperature drift faults, and in particular to a system for quickly locating circuit temperature drift fault points. Background Art

[0002] A general camera system generally includes a detector, an analog circuit part, a digital circuit part, and external interfaces (such as a display, a data transmission line, etc.), as Figure 1 shown. Among them, the analog circuit is responsible for processing the analog signals output by the detector, including noise reduction, amplification, and signal transmission, etc., and determines the image quality and noise level of the entire circuit. In an ultra-low-noise camera system, there are often two phenomena that occur during the hardware debugging process of the image circuit:

[0003] Phenomenon 1: As the circuit temperature rises or falls, one or more channels of noise interference, increased non-uniformity, or other functional problems (such as product power-off, abnormal operation of a certain function) occur in the video image;

[0004] Phenomenon 2: When the input signal remains unchanged, the mean value of the output image changes significantly with the ambient temperature, resulting in a deterioration of the output image.

[0005] The reason for the first phenomenon is generally problems such as echo generated by the impedance matching circuit, parameter drift of analog processing circuit devices, serious temperature drift of AD quantization noise or quality problems, and excessive temperature drift of link resistors. The reason for the second phenomenon is generally that the performance of the voltage reference chip or the voltage follower operational amplifier does not meet the requirements with temperature change, resulting in abnormal change of the differential operational amplifier reference voltage with temperature. The devices involved in the two phenomena include impedance matching resistors, matching capacitors, first-stage operational amplifiers, second-stage operational amplifiers, voltage references, devices in the AD isolation part, etc., basically covering all devices and fault points in the analog part.

[0006] The reasons for the above two phenomena can be attributed to the change of device parameters with temperature. At present, the troubleshooting methods for such faults by hardware engineers are mostly methods such as self-heating of the board, heating with a heat gun, and high and low temperature cycling in a temperature chamber. These methods are mostly applicable to overall temperature control or local heating of the board, and cannot perform fixed-point refrigeration and heating fault troubleshooting. When problems occur, multiple testing means need to be added to troubleshoot the fault points one by one and replace the devices one by one, greatly reducing the troubleshooting efficiency.

[0007] The present invention proposes a fixed-point heating and refrigeration system, which can perform temperature change operations on the target single-point area qualitatively and improve the troubleshooting efficiency. Summary of the Invention

[0008] In order to solve the above-mentioned deficiencies of the prior art, the present invention proposes a system for quickly locating circuit temperature drift fault points.

[0009] To solve the above technical problems, the present invention adopts the following technical solutions: A system for quickly locating the temperature drift fault point of a circuit, including a device under test, on which a temperature measurement system is provided;

[0010] The temperature measurement system includes a heat dissipation group, a TEC group, a heat conduction pad, a temperature measurement element, and a temperature controller;

[0011] The device under test is connected to a temperature measurement element, and the TEC group is tightly pressed against the device under test and the temperature measurement element through a heat conduction pad at the same time;

[0012] The heat dissipation group and the TEC group are adhered to each other through thermal conductive silicone grease;

[0013] The temperature controller circuit is connected to a temperature measurement element, a TEC group, and a power supply;

[0014] At high temperatures, the temperature controller converts electrical energy into heat energy through the TEC group. The heat energy is transferred to the device under test and the temperature measurement element through the heat conduction pad, and the temperature measurement element then feeds back the temperature signal of the heating point to the temperature controller to form a control closed loop;

[0015] At low temperatures, the heat energy is converted to the heat dissipation group through the TEC group, and stable temperature control tests are carried out by accelerating heat dissipation through the heat dissipation group.

[0016] Further, the heat dissipation group includes a heat sink, a fan, and an insulating tape. The bottom of the heat sink is connected to the TEC group. The fan is located on one side of the heat sink, and the top of the heat sink is wound with a rubber insulating tape.

[0017] Further, the TEC group includes multiple TEC chips with different specifications. The TEC chips are arranged and combined according to the specification sizes to form a TEC group. Thermal conductive silicone grease is used for adhesion between the TEC chips. The TEC chip with the smallest specification is interconnected with the device under test using thermal conductive glue. When the TEC chip is powered on in the forward direction, it is for refrigeration, and when powered on in the reverse direction, it is for heating. The power supply lines of all TEC chips are interconnected with the temperature controller.

[0018] Further, the temperature controller includes an AD conversion circuit, a temperature setting and display module, a driver corresponding to the TEC chip, and an MCU. The MCU is used for driving interconnection with the AD conversion circuit, the temperature setting and display module, and controls the three drivers with different PID parameters according to the feedback temperature and the set temperature. The driver is used to drive the corresponding TEC chip.

[0019] Further, the temperature controller is powered by an external power supply of 24V - 28V, ensuring that the power consumption range of the product does not exceed the human safety voltage and will not cause harm to the human body.

[0020] Compared with the prior art, the beneficial effects of the present invention:

[0021] 1. By taking advantage of the characteristics of the TEC semiconductor cooler that it can be heated or cooled, temperature control for fixed-point heating or cooling of the circuit can be achieved.

[0022] 2. Conduct fault troubleshooting and fixed-point performance testing of components with temperature changes.

[0023] 3. It can be extended to other signal processing fields to carry out research on temperature drift movement in other weak signal fields such as ultrasound and communication.

[0024] 4. The present invention utilizes the principle that the TEC semiconductor cooler is small in volume, power controllable, and can be refrigerated and heated, and is made into a device that can perform fixed-point heating and cooling. It performs fixed-point heating and cooling control on the suspected problem components of the analog circuit, and combines the output effect of the whole machine product to further judge whether the whole machine failure is caused by the temperature change of the suspected problem components, thereby improving the product debugging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a schematic diagram of the present invention.

[0026] Figure 2 is a schematic diagram of the TEC group.

[0027] Figure 3 is a schematic diagram of the heat dissipation group.

[0028] Figure 4 is a schematic diagram of the temperature controller. DETAILED DESCRIPTION OF THE INVENTION

[0029] The invention will be described in detail below with reference to the drawings and embodiments.

[0030] Embodiment 1

[0031] A system for quickly locating the temperature drift fault point of a circuit includes a device under test. As Figure 1 shown, the device under test is a suspected problem component. A temperature measurement system is provided on this problem component. The temperature measurement system includes a heat dissipation group, a TEC group, a heat conduction pad, a temperature measurement element, and a temperature controller. The temperature measurement element is a thermocouple. A thermocouple is placed 1 mm around the suspected problem component (if the surface of the problem component is large enough and insulated, the thermocouple can also be closely attached to the surface of the problem component).

[0032] As Figure 2As shown in the figure, the TEC group consists of three TEC chips with different specifications. These TEC chips are arranged and combined according to their specifications to form a TEC group. Thermal grease is used to bond the TEC chips together. The TEC chip with the smallest specification is interconnected with the suspected faulty device using thermal conductive glue. When a positive voltage is applied to the TEC chip, it operates in the cooling mode, and when a negative voltage is applied, it operates in the heating mode, which can meet the requirements of heating and cooling tests for the faulty device. The area of TEC chips on the market ranges from 10mm×10mm to 40mm×40mm. The maximum cooling capacity of a 10mm×10mm TEC chip is 5W, and the cooling capacity of a 40mm×40mm TEC chip ranges from 40W to 160W. They can be assembled according to actual needs. The power supply lines of all TEC chips are interconnected with the temperature controller, and the smallest TEC surface of the device is tightly pressed against the suspected faulty device and the thermocouple through a thermal conductive pad.

[0033] As Figure 3 shown in the figure, the heat dissipation group includes a long strip-shaped mesh heat sink, a fan, and an insulating tape. The bottom of the heat sink is connected to the TEC group. The fan is located on one side of the heat sink, and the top of the heat sink is wound with a rubber insulating tape. Among them, the bottom of the long strip-shaped mesh heat sink is bonded to the TEC group through thermal grease. During the design process, the air duct needs to be designed to ensure that the air duct crosses the mesh heat sink under the drive of the side fan, and the air inlet and outlet do not affect the heat dissipation environment of the test circuit as much as possible. The top environmental insulating rubber tape is used for operators to press. It is placed at the top for easy pressing and is designed to be insulating to ensure that the human body impedance does not affect the test circuit impedance.

[0034] As Figure 4 shown in the figure, the temperature controller includes an AD conversion circuit, a temperature setting and display module, drivers corresponding to the TEC chips, and an MCU. The MCU is used to drive and interconnect with the AD conversion circuit, temperature setting, and display module, and perform different PID parameter controls on the three drivers according to the feedback temperature and the set temperature. The drivers are used to drive the corresponding TEC chips. The temperature controller is powered by an external 24V - 28V power supply to ensure that the product's power consumption range does not exceed the human safety voltage and cause harm to the human body. The AD conversion circuit is used to monitor the temperature of the environment around the faulty device. The temperature setting and display module is used to set whether cooling or heating is required and the temperature to be controlled. The temperature controller includes three drivers for driving three external TEC chips. Among them, driver 1 drives the high-power TEC chip to provide a small TEC working environment with relatively high or low temperature, and driver 3 drives the low-power driver chip for precise temperature control.

[0035] The temperature controller has two working modes: fixed-point temperature control and cyclic temperature control. During fixed-point temperature control, the temperature controller operates at the maximum power to quickly stabilize the temperature to the target temperature. During cyclic temperature control, the user can set the temperature cycle curve, including but not limited to the heating slope, the highest point temperature, the cooling slope, the lowest point temperature, and the number of cycles.

[0036] The thermostat circuit is connected to a temperature measuring element, a TEC group and a power supply;

[0037] At high temperatures, the thermostat converts electrical energy into heat energy through the TEC group. The heat energy is transferred to the device under test and the temperature measuring element through a heat conducting pad. The temperature measuring element then feeds back the temperature signal of the heating point to the thermostat to form a control closed loop;

[0038] At low temperatures, the heat energy is converted to the heat dissipation group through the TEC group, and stable temperature control tests are carried out by accelerating heat dissipation through the heat dissipation group.

[0039] Working principle: When troubleshooting high-temperature fixed-point function at room temperature, place a thermocouple 1 mm around the "suspected problem device (hereinafter referred to as the problem device)" (if the surface of the problem device is large enough and insulated, the thermocouple can also be closely attached to the surface of the problem device). Press the smallest TEC surface of the device tightly against the "problem device" and the hot thermocouple through a heat conducting pad. Select the target temperature to be controlled on the thermostat, for example, 60 °C. At this time, the thermostat converts electrical energy into heat energy through the TEC group. The heat energy is transferred to the "problem device" and the thermocouple through the heat conducting pad. The thermocouple feeds back the temperature signal of the heating point to the thermostat to form a control closed loop. Because the TEC group is used in this method, the temperature of the contact point "problem device" can be raised to the target temperature within a few seconds. Then, according to the working state of the product (circuit) when only the "problem device" works at high temperature and other circuits work at room temperature, it is determined whether there is a problem with the "problem device".

[0040] Similarly, when troubleshooting low-temperature fixed-point faults, only set the above target temperature to a low temperature, for example, -40 °C. Because the TEC group has a strong instantaneous refrigeration capacity, the heat energy of the target device is converted to the heat dissipation group through the TEC group, and stable temperature control tests are carried out by accelerating heat dissipation through the fan.

[0041] When performing performance tests, on the basis of fixed-point fault troubleshooting, a temperature curve to be cycled can be set on the device thermostat. The user can observe the performance of the "problem device" at different temperatures, or the impact of its performance at different temperatures on the circuit (the whole machine, the system).

[0042] The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the patent and protection scope of the present invention should be subject to the appended claims.

Claims

1. A system for quickly locating circuit temperature drift fault points, characterized in that: The device comprises a device to be tested, wherein a temperature measuring system is arranged on the device to be tested; The temperature measurement system includes a heat dissipation group, a TEC group, a thermal pad, a temperature measurement element, and a temperature controller; The device under test is connected to a temperature measuring element, and the TEC group is simultaneously pressed and connected to the device under test and the temperature measuring element through a thermal pad; The heat dissipation group and the TEC group are bonded together by thermal conductive silicone grease; The temperature controller circuit is connected with a temperature measuring element, a TEC group and a power supply; At high temperatures, the thermostat converts electrical energy into thermal energy through the TEC group. The thermal energy is transferred to the device under test and the temperature measuring element through the thermal pad. The temperature measuring element then feeds back the temperature signal of the heating point to the thermostat to form a control closed loop. At low temperatures, the heat energy is transferred to the heat dissipation group through the TEC group, and the heat dissipation is accelerated by the heat dissipation group to perform a stable temperature control test.

2. A system for quickly locating circuit temperature drift fault points as claimed in claim 1, characterized in that: The heat dissipation group includes a heat sink, a fan and an insulating tape. The bottom of the heat sink is connected to the TEC group. The fan is located on one side of the heat sink. The top of the heat sink is wrapped with a rubber insulating tape.

3. A system for quickly locating a circuit temperature drift fault point according to any one of claims 1 to 2, characterized in that: The TEC group includes multiple TEC sheets of different specifications, which are arranged and combined according to their sizes to form a TEC group. The TEC sheets are bonded together using thermal grease, and the smallest TEC sheet is interconnected with the device under test using thermal adhesive. The TEC sheet is powered in the forward direction for cooling and in the reverse direction for heating. The power supply lines of all TEC sheets are interconnected with the temperature controller.

4. A system for quickly locating circuit temperature drift fault points as claimed in claim 3, characterized in that: The temperature controller includes an AD conversion circuit, a temperature setting and display module, a driver corresponding to the TEC sheet, and an MCU. The MCU is used to drive and interconnect with the AD conversion circuit, the temperature setting and display module, and perform different PID parameter control on the three drivers according to the feedback temperature and the set temperature. The driver is used to drive the corresponding TEC sheet.

5. A system for quickly locating circuit temperature drift fault points as claimed in claim 4, characterized in that: The thermostat is connected to an external power supply of 24V-28V to ensure that the power consumption range of the product does not exceed the safe voltage for the human body and will not cause harm to the human body.

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