JPH04342004A - thermal control device - Google Patents

Abstract

PURPOSE:To expand the stable temperature using range of a thermoelectronic cooling and heating element by using an air cooling fan and a heating resistor, and setting the upper and the lower limit working temperatures thereof. CONSTITUTION:The detected temperature is converted into voltage by a thermistor 1, and when this detected voltage exceeds the voltages set by volumes 11, 12, switching elements 14, 19 are operated so as to operate the air cooling fan 15 or the heating resistor 20, and the using temperature range can be expanded by using the usual air cooling fan 15 and the usual heating resistor 20 while the capacity of the thermoelectronic coiling and heating element 10 is left as it is.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control device for an air conditioner in an electronic device or the like.

0002

2. Description of the Related Art Conventionally, equipment air conditioning has been used to prevent internal temperature rises due to self-heating and to operate the equipment stably within a certain temperature range. Therefore, in most cases, excess heat is dissipated by forced air cooling, but in some devices that require use within a precise temperature range, the temperature of the parts or parts is maintained constant. It was extremely expensive to prepare and house a special constant temperature bath.

[0003]More recently, semiconductor components that must be used within a precise and stable temperature range, such as laser diodes, have come to be equipped with electronic cooling and heating elements that have a self-cooling function. Since the heat capacity of the ambient temperature or internal temperature of the equipment is larger than the self-cooling capacity, below a certain temperature or above a certain temperature, the control ability of the electronic cooling element is exceeded, causing damage to parts, excessive current flowing to the electronic cooling element, and heat generation. There was a risk that the vehicle would run out of control and damage parts.

0004

[Problem to be Solved by the Invention] In this way, it is attempted to ensure performance under a wide range of ambient temperature changes for components in electronic devices, which are generally required to be used within a precise temperature range. This resulted in the problem of thermal runaway of the electronic cooling element, which resulted in restrictions on the arrangement of components within the device and on heating and heat dissipation.

[0005] In view of the above-mentioned problems, the present invention has been developed so that even if there is a significant change in ambient temperature or a temperature rise due to equipment self-heating,
It is an object of the present invention to provide a thermal control device that makes it easy to obtain a precise and stable temperature range for a component or section.

[0006]

[Means for Solving the Problems] The thermal control device of the present invention includes:
An electronic cooling/heating element, a temperature detection element integrated with the electronic cooling/heating element, a control circuit for controlling the current of the electronic cooling/heating element, a temperature setting circuit for setting upper and lower temperature limits, a temperature heating resistor, and air cooling. It is characterized by being configured with a device.

[0007]

[Function] The thermal control device of the present invention includes an ordinary cooling fan used in general equipment, a heating resistor that can be mounted on a printed board, and a circuit that effectively controls heating and cooling of these. This makes it possible to control the operating temperature of parts used within a certain temperature range in electronic equipment and to expand the operating temperature range with an inexpensive configuration.

[0008]

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, 1 is a thermistor integrated with the electronic cooling element, and its resistance value changes in proportion to temperature changes. 2 is the operating temperature (Figure 2)
With the volume that sets T1, these elements 1, 2, 3, 4
It forms a resistive bridge and converts the temperature of the component into voltage. Figure 2a shows how the resistance value of the thermistor 1 changes due to a change in temperature and is converted into voltage. This detected voltage is amplified by an amplifier 5 and passes through a resistor 6 to drive circuits (elements) 7 and 8 that drive the electronic cooling element 10. The resistor 9 is a protective resistor to prevent runaway. (FIG. 2) b shows the pattern and shows a state where the maximum current is limited by the resistor 9. The output of amplifier 5 is also connected to comparator 13
, 18. A bias potential is applied to the comparator 13 by a resistor 11 and a potentiometer 12, and the amplifier 5
When the output of the cooling fan 15 exceeds this bias potential, the switching element 14 is turned on.
to lower the temperature of the parts. Similarly, the comparator 18 has a bias in the opposite direction to that of the comparator 13 through the resistor 16.
is applied by the regulator 17, and when the output of the amplifier 5 exceeds this bias potential, the switching element 19 is turned on, heating the heating resistor 20 and raising the component temperature. (Figure 2) c is the temperature T3 set by the volume control 12
The temperature T2 set by the volume control 17 and the on/off timing of the air cooling fan 15 and the heating resistor 20 are shown.

According to this configuration, for example, when the ambient temperature is cold, the switching element 19 is turned on until the electronic cooling element 10 and its temperature control become effective, and the heating resistor 20 operates to cool the components and their Increase the surrounding temperature. Conversely, when the temperature is high, for example, the switching element 14 is turned on, and the cooling fan 15 operates to lower the temperature of the components and their surroundings. When the electronic cooling/heating element 10 is within the thermal control range, the switching elements 14 and 19 are both turned off, and the heating resistor 20 and air cooling fan 15 stop operating. In this way, the heating resistor 20 and the air cooling fan 15 compensate for the insufficient capacity of the electronic cooling element 10, and thermal balance is maintained at the upper and lower temperature limits set as shown in d (Fig. 2), resulting in a stable operating temperature. .

0010

Effects of the Invention As described above, the thermal control device of the present invention uses an ordinary cooling fan and a heating resistor without using a special constant temperature bath for temperature stabilization, thereby improving the temperature of electronic cooling elements. It is possible to expand the operating temperature range while maintaining the same performance.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a thermal control device according to an embodiment of the present invention.

[Figure 2] Characteristic diagram showing operating temperature conditions of the present invention

[Explanation of symbols]

1 Thermistor 2, 12, 17 Volume 3, 4, 6, 9, 11, 18 Resistor 5 Amplifier 7, 8 Electronic cooling element driving transistor 10
Electronic cooling and heating elements 13, 18 Comparators 14, 19 Switching element 15 Air cooling fan 20 Heating resistor

Claims (1)

[Claims] 1. An element having an electronic cooling/heating function, a circuit for detecting temperature such as a thermistor, a circuit for converting temperature into voltage and driving an electronic cooling/heating element, and a circuit for setting temperatures for heating and air cooling. A thermal control device consisting of a heating/air cooling device that is activated when the temperature exceeds a set point.