JP3856192B2 - Temperature chamber - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thermostatic chamber that maintains circuit elements such as high resistance elements at a predetermined temperature.
[0002]
[Prior art]
4 is a configuration diagram of a conventional thermostatic chamber, FIG. 4 (A) is a front view, and FIG. 4 (B) is a cross-sectional view showing a state cut along line IV-IVB in FIG. 4 (A). is there.
The resistance temperature coefficient of a high resistance element (500 to 10000 MΩ) such as a circuit element is generally large (100 to 200 ppm / ° C), and in order to realize a stable minute current amplifier (electrometer), the high resistance element is kept constant. It is necessary to make it. For this purpose, a thermostatic chamber that controls the high resistance element to a constant temperature is used.
[0003]
A conventional thermostatic chamber 101 shown in FIG. 4 includes a high-resistance element 102 as a circuit element, an insulating material 103, a cylinder block 104, a heater wire 105, a thermistor 107, and a shield cylinder 111. The insulating material 103 is a member that houses the high resistance element 102 and electrically insulates the high resistance element 102. The insulating material 103 supports the resistance lead wires 102a and 102b of the high resistance element 102, and holds the high resistance element 102 in space. The cylinder block 104 is an aluminum cylindrical member that accommodates the insulating material 103, and the high resistance element 102 is installed in the center of the cylinder block 104 via the insulating material 103. The heater wire 105 is a heating heater (heating element) that heats the cylinder block 104, and is wound around the outer peripheral surface of the cylinder block 104 many times. The thermistor 107 is a member that detects the temperature of the cylinder block 104 and is embedded in a storage hole 104 a formed at the end of the cylinder block 104. The shield cylinder 111 is a cylindrical member that covers the outer peripheral surface of the heater wire 105 and electrically shields the heater wire 105. The shield cylinder 111 is fixed to the cylinder block 104 by set screws 111a and 111b.
[0004]
In the conventional thermostat 101, a temperature control circuit (not shown) compares the temperature signal detected by the thermistor 107 with a set temperature, and the current flowing through the heater wire 105 is intermittent. And in the conventional thermostat 101, the temperature of the cylinder block 104 and the high resistance element 102 was kept constant, and the circuit characteristics were stabilized.
[0005]
[Problems to be solved by the invention]
However, the conventional thermostatic chamber 101 has a problem in that the assembly workability is poor because the heater wire 105 must be wound around the cylinder block 104 many times.
[0006]
The subject of this invention is providing the thermostat which can be assembled easily.
[0007]
[Means for Solving the Problems]
The present invention solves the above problems by the following means.
In addition, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention of claim 1
A thermostatic chamber for maintaining the circuit element (2) at a predetermined temperature, the holding block (4) for holding the circuit element, the heating element (5) for heating the circuit element, and the holding from the heating element side. First joining means (8a) capable of attaching and detaching the heating element to the holding block (4) from the outside of the holding block (4) on the outer surface of the holding block so that heat is transferred to the block side; While heating the circuit element, the amount of heat generated by the heating element is controlled, the heating control element (6) that also generates heat, and the holding block so that heat is transferred from the heating control element side to the holding block side. A thermostat (1) including a second joining means (8b) capable of attaching and removing the heat generation control element to and from the holding block (4) from the outside of the holding block (4) on an outer surface .
[0009]
The invention of claim 2 is the constant temperature bath of claim 1, wherein the first and second joining means, the joining so as to sandwich the holding block between said heating element and said heating control device It is a thermostat characterized by this.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
Hereinafter, the first embodiment of the present invention will be described in more detail with reference to the drawings.
1 is a configuration diagram of a thermostatic chamber according to a first embodiment of the present invention, FIG. 1 (A) is a front view, and FIG. 1 (B) is cut along the line I-IB in FIG. 1 (A). It is sectional drawing which shows the state which carried out, and FIG.1 (C) is a side view. FIG. 2 is a circuit diagram showing a temperature control circuit of the thermostatic chamber according to the first embodiment of the present invention. Note that the same members as those shown in FIG. 4 are denoted by corresponding numbers, and detailed description thereof is omitted.
[0012]
The thermostat 1 is a device that maintains the high resistance element (circuit element) 2 at a predetermined temperature. The constant temperature bath 1 includes a high resistance element 2, an insulating material 3, a constant temperature block 4, a heating element 5, a heating control element 6, a thermistor 7, joining means 8 a and 8 b shown in FIG. The temperature control circuit 9 shown in FIG.
[0013]
The constant temperature block 4 is a holding block that holds the high resistance element 2 and the insulating material 3. The high resistance element 2 is accommodated and installed in the central portion of the constant temperature block 4 via an insulating material 3. As shown in FIGS. 1A and 1B, a storage hole 4a is formed at the center of the lower portion of the constant temperature block 4, and a temperature detection thermistor 7 is stored in the storage hole 4a. It is attached. A heat generating element 5 and a heat generating control element 6 are respectively attached to both side surfaces of the constant temperature block 4.
[0014]
The heating element 5 is a resistor or the like that heats the high resistance element 2. The heat generating element 5 has a T0-220 type symbol representing the shape of the semiconductor element. The heat generation control element 6 is a transistor or the like that controls the amount of heat generated by the heat generation element 5 so that the high resistance element 2 is maintained at a predetermined temperature. The heat generation control element 6 is a T0-220 type having the same shape as the heat generation element 5.
[0015]
The joining means 8a is a set screw or the like that joins the constant temperature block 4 and the heating element 5 so that heat is transmitted from the heating element 5 side to the constant temperature block 4 side. The joining means 8b is a set screw or the like that joins the constant temperature block 4 and the heat generation control element 6 so that heat is transmitted from the heat generation control element 6 side to the constant temperature block 4 side. As shown in FIGS. 1A and 1C, the joining means 8a and 8b are joined so as to sandwich the thermostatic block 4 between the heating element 5 and the heating control element 6, and the heating element 5 and the heating control element are joined. The constant temperature block 4 is integrated and held by 6.
[0016]
The temperature control circuit 9 is an electric circuit for controlling the heat generation amount of the heat generating element 5. As shown in FIG. 2, the temperature control circuit 9 includes a circuit voltage (power source) V, a reference voltage (power source) V ₀ , resistors r ₁ , r ₂ , r ₃ , R, a transistor Tr, a circuit A, It is composed of Here, the resistor r ₂ corresponds to the thermistor 7, the resistor R corresponds to the heating element 5, and the transistor Tr corresponds to the heating control element 6.
[0017]
Next, the operation of the thermostatic chamber according to the first embodiment of the present invention will be described.
The temperature control circuit 9 shown in FIG. The output of the circuit A is the current flowing through the resistor R through the transistor Tr so that the divided value r ₂ · V / (r ₁ + r ₂ ) by the resistors r ₁ and r ₂ matches the reference voltage V _0. ON / OFF control. Since the ON / OFF output of the circuit A is the circuit voltage V or zero, the circuit voltage V or zero is applied to the base of the transistor Tr via the resistor r ₃ to perform an ON / OFF switching operation, and the transistor Tr itself Does not generate heat, and only the resistor R generates heat (V ² / R). Heat resistance R occurs is transmitted to the thermistor 7 through the thermostatic block 4 shown in FIG. 1 (the resistance r _2), together with the thermistor 7 (resistance r ₂₎ is controlled at a constant temperature, constant-temperature block 4 also thermostatic It becomes. In this way, the thermostatic operation of the thermostatic block 4 is performed by temperature feedback control.
[0018]
The thermostatic chamber according to the first embodiment of the present invention has the effects described below.
In the first embodiment, the joining means 8a joins the constant temperature block 4 and the heating element 5 so as to conduct heat from the heating element 5 side to the constant temperature block 4 side. For this reason, the operation | work which winds the heater wire 105 around the cylinder block 104 in the conventional thermostat 101 shown in FIG. 4 becomes unnecessary. As a result, the winding work and the winding device are not necessary, and the configuration of the thermostatic chamber 1 is simplified, so that the assembling work can be greatly improved.
[0019]
(Second Embodiment)
FIG. 3 is a circuit diagram showing a temperature control circuit of a thermostatic chamber according to the second embodiment of the present invention.
The temperature control circuit 10 of the second embodiment is obtained by adding a resistor r ₄ to the temperature control circuit 9 of the first embodiment. Since the ON / OFF output of the circuit A shown in FIG. 3 is the circuit voltage V or zero, the potential V / 2 is applied to the base of the transistor Tr via the resistors r ₃ and r ₄ . Since the forward voltage between the base and emitter of the transistor Tr is small and neglected, a potential V / 2 is applied to the resistor R, and a potential V / 2 is applied between the emitter and collector of the transistor Tr. At this time, since the current flowing through the resistor R and the transistor Tr is V / (2R), the amount of heat generated by the resistor R is (V / 2) ² / R = V ² / (4R), and the transistor Tr The amount of generated heat is V / 2 · V / (2R) = V ² / (4R), which is the same amount. Even in this state, as in the first embodiment, the thermostatic operation of the thermostatic block 4 is performed by temperature feedback control.
[0020]
The thermostat according to the second embodiment of the present invention has the following effects in addition to the effects of the first embodiment.
In the second embodiment, the high-resistance element 2 is heated, and the heat generation control element 6 controls the heat generation amount of the heat generation element 5 so that heat is transferred from the heat generation control element 6 side to the temperature control block 4 side. 4 and the heat generation control element 6 are joined by the joining means 8b. As a result, since the heat generation control element 6 itself actively generates heat, the heat generation unevenness is reduced, the temperature ripple of the constant temperature block 4 is reduced, the temperature distribution of the constant temperature bath 1 is substantially uniform, and the circuit characteristics are improved. can do.
[0021]
(Other embodiments)
The present invention is not limited to the embodiment described above, and various modifications or changes are possible, and these are also within the scope of the present invention. For example, in this embodiment, the heat generating element 5 and the heat generating control element 6 are attached to the thermostatic block 4 by the set screws 4a and 4b, but they may be joined by an adhesive or the like. In this embodiment, the high resistance element 2 is described as an example of an element that requires constant temperature, but the present invention is not limited to this. For example, the present invention can be applied to a Zener diode for generating a reference voltage.
[0022]
【The invention's effect】
As described above, according to the present invention, the holding block and the heating element are joined by the joining means so that heat is transferred from the heating element side to the holding block side, so that the thermostat can be easily assembled. In addition, according to the present invention, the first joining means joins the holding block and the heating element so that heat is transferred from the heating element side to the holding block side, thereby heating the circuit element and controlling the heat generation amount of the heating element. Since the second joining means joins the holding block and the heat generation control element so that heat is transmitted from the heat generation control element side to the holding block side, the heat generation unevenness is reduced and the temperature distribution in the thermostat is made substantially uniform. be able to.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a thermostatic chamber according to a first embodiment of the present invention, (A) is a front view, and (B) is a cross-sectional view showing a state cut along line I-IB in (A) (C) is a side view.
FIG. 2 is a circuit diagram showing a temperature control circuit of the thermostatic chamber according to the first embodiment of the present invention.
FIG. 3 is a circuit diagram showing a temperature control circuit of a thermostatic chamber according to a second embodiment of the present invention.
4A and 4B are configuration diagrams of a conventional thermostatic chamber, FIG. 4A is a front view, and FIG. 4B is a cross-sectional view showing a state cut along line IV-IVB in FIG.
[Explanation of symbols]
1 Constant temperature bath 2 Circuit element 3 Insulating material 4 Constant temperature block (holding block)
5 Heating element (R)
6 Heat generation control element (Tr)
7 Thermistor (r ₂ )
8a, 8b Joining means 9, 10 Temperature control circuit

Claims (2)

A thermostat for maintaining circuit elements at a predetermined temperature,
A holding block for holding the circuit element;
A heating element for heating the circuit element;
A first joining means capable of attaching and detaching the heat generating element to and from the holding block from the outside of the holding block so that heat is transferred from the heat generating element side to the holding block side;
A heating control element that heats the circuit element, controls the amount of heat generated by the heating element, and also generates heat,
A second joining means capable of attaching and detaching the heat generation control element to the holding block from the outside of the holding block so that heat is transferred from the heat generation control element side to the holding block side;
A thermostat containing. In the thermostat according to claim 1,
  The first and second joining means are joined so as to sandwich the holding block between the heating element and the heating control element;
  A constant temperature bath.

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