JP3685005B2 - Peltier device motion detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a Peltier element motion detection apparatus, and more particularly to a motion detection apparatus suitable for use in a temperature control apparatus that heats and absorbs, for example, a semiconductor wafer using the Peltier element.
[0002]
[Prior art]
In recent years, from the viewpoint of suppressing global warming, Peltier devices have attracted attention as an alternative heating and heat absorption means for CFCs.
[0003]
For example, a configuration as shown in FIG. 6 has been proposed as a temperature control device for controlling the temperature of a controlled object with this Peltier element.
[0004]
That is, a temperature measuring sensor 3 is disposed in the vicinity of the Peltier element 1 and connected to the input unit 5, and the input unit 5 outputs an electrical signal as a measured value PV corresponding to the measured temperature to the controller 7, The controller 7 compares the set value SV with the measured value and outputs a PWM signal based on a control output so as to reduce the deviation to the drive unit 9, and the drive unit 9 performs switching according to the PWM signal. The configuration was such that a signal was formed and output to the H-bridge circuit 11.
[0005]
This H-bridge circuit 11 comprises a P-channel and N-channel MOS • FET transistor FET1 and FET4, a P-channel and N-channel MOS • FET transistor FET3 and FET2 connected in series, and a connection point between the MOS • FET transistors FET1 and FET4. When the Peltier device 1 is connected between the connection points of FET3 and FET2, and the MOS / FET transistors FET1 and FET2 are simultaneously turned on / off by the switching signal from the drive unit 9, the MOS / FET transistors FET3 and FET4 are simultaneously turned on. It is designed to be turned off / on.
[0006]
In such a temperature control device, the controller 7 compares the temperature measurement value PV by the Peltier element 1 with the set value SV, the temperature set value SV for the control object is higher than the control object temperature, and for example, the temperature measurement value PV is the set value. If it is lower than SV, a PWM signal based on the control output that reduces the deviation is output to the drive unit 9, and the drive unit 9 based on the PWM signal, as shown in FIG. The FET transistors FET1 and FET2 are turned on, while the MOS FET transistors FET3 and FET4 are turned off, and a drive current is supplied to the Peltier element 1 from the MOS FET transistor FET1 side to the FET2 side to generate heat. it can.
[0007]
On the other hand, for example, if the temperature set value SV for the controlled object is low and the temperature measured value PV is higher than the set value SV, the controller 7 outputs a PWM signal based on a control output that reduces the deviation to the drive unit 9. 7, the drive unit 9 turns on the MOS • FET transistors FET 3 and FET 4 of the H-type bridge circuit 11, while turning off the MOS • FET transistors FET 1 and FET 2. A drive current can be passed from the FET transistor FET3 side to the FET4 side to perform an endothermic operation.
[0008]
Therefore, if the controller 7 is configured to be able to output a PWM signal based on the control output so that the deviation between the temperature measurement value PV and the set value SV is small, the Peltier element 1 can be controlled to a certain temperature.
[0009]
Moreover, in this temperature control device, the MOS / FET transistors FET1 to FET4 exhibiting resistive on-conduction loss are used as the switch elements for switching the drive current flowing to the Peltier element 1, so that the bipolar transistor is used as the switch element. In comparison, there is an advantage that the on-conduction loss is reduced.
[0010]
For example, as shown in FIG. 8, such a temperature control device abuts a heat load 13 as an object to be cooled on the heat absorption surface (cooling surface) of the Peltier element 1 and a heat exchanger 15 abuts on the heat generating surface side. The pump 17, the heat exchanger 15, and the tank 17 are connected from the tank 17 through the pipe 21 to circulate the cooling medium, and the heat absorbing surface (cooling surface) of the Peltier device 1 is cooled while appropriately cooling the heat generating surface side of the Peltier device 1. ) Is efficiently cooled.
[0011]
In FIG. 8, illustrations other than the Peltier element 1 in FIG. 6 are omitted.
[0012]
[Problems to be solved by the invention]
However, the temperature control device using a Peltier element has the following problems.
[0013]
That is, when the heat transfer characteristic on the heat dissipation side of the Peltier element 1 is deteriorated, the temperature on the heat dissipation side rises. However, since the Peltier element 1 has heat conduction from the heat dissipation surface to the cooling surface, the cooling side is accordingly accompanied. The temperature on the cooling side is likely to rise, and in the general usage configuration as shown in FIG.
[0014]
In such a case, in the above-described temperature control device, in order to bring the measured temperature PV by the sensor 3 close to the set temperature SV, the driving current for cooling the Peltier element 1 is controlled to increase, The temperature tends to rise due to the deterioration of the heat transfer characteristics and then causes an increase in temperature on the cooling side. In an extreme case, there is a risk of causing thermal runaway.
[0015]
In particular, while the Peltier effect exhibited by the Peltier element 1 is proportional to the drive current, the Joule heat due to the Peltier resistance exhibited by the Peltier element 1 is proportional to the square of the drive current, and increasing the drive current increases the heat dissipation side and the cooling side. As a result, the thermal runaway of the Peltier element 1 is likely to increase.
[0016]
Since the Peltier device 1 generates a Seebeck voltage corresponding to the temperature difference generated from the heat radiation surface to the cooling surface, if this Seebeck voltage can be detected, it is possible to grasp the thermal runaway of the Peltier device 1. In the direct current drive described above, which is one general drive method, it cannot be detected unless the drive voltage is completely turned off, and once the applied power is turned off, the temperature control is disturbed.
[0017]
Further, when the Peltier element 1 is subjected to an endothermic operation in a humid environment, the surrounding environment exceeds the amount of saturated water vapor to cause dew condensation, and the Peltier element 1 adheres to the Peltier element 1 between electrodes (not shown). If the Peltier element 1 is used in an environment with a severe thermal cycle, the Peltier element 1 may be caused by vibration due to thermal contraction or mechanical stress of a thermal load. It becomes easy to produce a space | gap between the element 1 and the thermal load 13, and the deterioration of the Peltier element 1 is accelerated.
[0018]
Further, for example, the endothermic flow does not increase in proportion to the drive current that flows through the Peltier element 1, and the maximum endothermic flow is shown at a certain current value Im as shown in FIG.
[0019]
Therefore, if the current value Im is exceeded, the endothermic power of the Peltier element 1 decreases, so that the drive current value flowing through the Peltier element 1 is appropriately measured from the viewpoint of preventing deterioration of the Peltier element 1 and achieving appropriate temperature control. Is preferred.
[0020]
For example, when the Peltier device 1 is driven based on the PWM signal, if the load power supply voltage is erroneously selected to be larger than the voltage corresponding to Im, the duty ratio of the PWM signal becomes 100% when the power is turned on. Then, the effective current of the load becomes larger than Im, the temperature control diverges and becomes an overvoltage, and it becomes difficult to ensure effective heating and heat absorption, and the deterioration of the Peltier element 1 is easily accelerated.
[0021]
Therefore, in a conventional temperature control apparatus using the Peltier element 1, an operation detection apparatus for detecting an operation state of the Peltier element 1 to easily detect a failure such as a thermal runaway and suppressing deterioration of the Peltier element 1. Was requested.
[0022]
Therefore, as a result of earnest research on the temperature control device using the Peltier element 1 in addition to the operation of the Peltier element 1, the present inventor has conducted a drive current to the Peltier element by a switching signal based on the PWM signal during one cycle. Focusing on a certain point of the on / off section of the drive current flowing through the Peltier element 1, and focusing on the fact that an electromotive voltage proportional to the temperature difference is generated based on the Seebeck effect in the off section where the drive current does not flow through the Peltier element 1. Thus, the present invention has been completed.
[0023]
The present invention has been made under such circumstances, and an object of the present invention is to provide an operation detection device capable of detecting the operation state of a Peltier element being controlled by a switching signal based on a PWM signal.
[0024]
[Means for Solving the Problems]
In order to solve such a problem, the motion detection apparatus of the present invention includes a plurality of Peltier elements that generate heat or absorb heat according to the direction of the drive current to flow, and a gate circuit to which a switching signal based on a PWM signal is applied. H-bridge circuit that switches the direction of the drive current that flows to the Peltier element connected between the MOS-FET transistors, and during the heat generation operation or the heat absorption operation, during a certain period in the PWM signal A switch unit for switching and inputting the potential of the Peltier element in the first off period, and a detection unit for detecting the Seebeck voltage of the Peltier element from the input potential of the off period.
[0025]
In the present invention, the switch portion is formed so as to have a function of switching and inputting the potential of the Peltier element in the ON period during the heat generation operation or the heat absorption operation, and the input ON section potential. From the above, it is possible to form the detection unit so as to have a function of detecting the load voltage of the Peltier element.
[0026]
In the present invention, the function of switching and inputting the potential of the Peltier element in the second off period different from the first off period during the heat generation operation or the heat absorption operation, and the second off period thereof, The switch section is formed so as to have a function of switching and inputting a predetermined constant current to the Peltier element during the off period of the circuit, and a function of detecting the resistance of the Peltier element from the input potential and constant current of the second on period. It is possible to form the detection portion so as to have the above.
[0027]
Furthermore, in the present invention, the power supply voltage applied to the H-bridge circuit in the third off section that is different from the first and second off sections in the fixed period during the heat generation operation or the heat absorption operation. The switch unit can be formed so as to have a function of switching input, and the detection unit can be formed so as to have a function of detecting the input power supply voltage.
[0028]
Furthermore, in the present invention, an N-channel MOS / FET transistor is combined to form the H-bridge circuit, and the signal flowing through each gate circuit of the MOS / FET transistor is returned to the previous stage via a return line. It is preferable to connect MOS / FET transistors.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the part which is common in a prior art example.
[0030]
FIG. 1 is a block diagram showing an embodiment of a motion detection apparatus according to the present invention.
In FIG. 1, a sensor 3 is a temperature measuring element such as a thermocouple, for example, and is arranged in the vicinity of a well-known Peltier element 1 or a control target (not shown) to be heated and cooled by the Peltier element 1 described later. 5 is connected.
[0031]
The input unit 5 functions together with the sensor 3 and outputs a detected temperature signal as the temperature measurement value PV, and is connected to the controller 23.
[0032]
The controller 23 includes, for example, a control calculation unit that performs PID calculation and a PWM generator (not shown) that generates a PWM signal, and the temperature measurement value PV from the input unit 5 and a predetermined temperature set value SV. Then, for example, a PID calculation is performed by the control calculation unit and a control output amount is output so as to reduce the deviation, and a PWM signal (2) obtained by converting the control output amount into a pulse width signal (duty ratio) by the PWM generator. Value control signal).
[0033]
FIG. 2 shows a PWM signal output from the controller 23. When the temperature measurement value PV is higher than the set value SV, the duty ratio (ON period) output as shown in FIGS. When the temperature measurement value PV is low beyond the set value SV, it is a binary signal with a large duty ratio (ON period) that is output as shown in FIGS.
[0034]
Note that the controller 23 outputs a PWM signal with a control load factor of 100% as a substantial load factor of 96%, and the control load factor will be described below. The relationship between the control load factor and the substantial load factor is, for example, as shown in FIG.
[0035]
When the temperature set value SV for the control target is lower than the ambient temperature of the control target and the temperature measurement value PV is higher than the set value SV, the controller 23 increases the control output amount such as PID calculation from 0% to 50%. The PWM signal having a duty ratio of 100% to 0% within the range is output to the drive unit 9 and the Peltier element 1 has a function of performing an endothermic operation.
[0036]
On the other hand, when the temperature set value SV for the control target is higher than the ambient temperature of the control target and the temperature measurement value PV is lower than the set value SV, the control output amount for PID calculation or the like is in the range of 50% to 100%. In this range, the PWM signal having a duty ratio of 0% to 100% is output to the drive unit 9 and the Peltier element 1 is operated to generate heat.
[0037]
As shown in FIG. 3, the controller 23 appropriately divides the OFF section into three sections for each period of the PWM signal and adds four ON measurement sections {1}, {2}, {3} It is divided into ▼ and ④ and has a function of outputting a switch command signal for each measurement section ▲ 1 to ▲ 4.
[0038]
When the duty ratio of the PWM signal changes, this switch command signal expands and contracts in accordance with each measurement section (1) to (4). The details of the switch command signal will be described later.
[0039]
The drive unit 9 has a known circuit configuration that forms a binary switching signal corresponding to the duty ratio of the PWM signal, and is connected to the H bridge circuit 11.
[0040]
That is, as shown in FIG. 7 described above, when the Peltier element 1 is operated to generate heat, a switching signal for turning on FET transistors FET1 and FET2 (to be described later) of the H bridge circuit 11 is output to the gate circuits. When the Peltier device 1 performs an endothermic operation, it has a function of outputting a switching signal to turn on FET transistors FET3 and FET4, which will be described later, to these gate circuits.
[0041]
As shown in FIG. 4, the H-bridge circuit 11 has the drain (D) of the P-channel MOS • FET transistor FET1 connected to the power source Vc and the source (S) connected to the drain (D) of the N-channel MOS • FET transistor FET4. The drain (D) of the P-channel MOS • FET transistor FET3 is connected to the power source Vc, the source (S) is connected to the drain (D) of the N-channel MOS • FET transistor FET2, and the sources of the MOS • FET transistors FET2 and FET4 are connected. (S) It is formed by common grounding, and the Peltier element 1 is connected between the connection point of the MOS / FET transistors FET1 and FET4 and the connection point of the FET3 and FET2.
[0042]
In FIG. 4, the connection state between the drive unit 9 and the gates G of the MOS • FET transistors FET1 to FET4 is not shown.
[0043]
Returning to FIG. 1, reference numeral 25 denotes a power supply unit for supplying power Vc to the MOS-FET transistors FET 1, FET 3 and other parts and circuits constituting the operation detection device of the present invention, and reference numeral 27 denotes a connection to the H bridge circuit 11. The switch part.
[0044]
As shown in FIG. 4, the switch unit 27 includes a switch element SW1 having one end connected to the drain D of the MOS / FET transistors FET1 and FET3, and a switch having one end connected to the connection point of the MOS / FET transistors FET1 and FET4. A switch element SW3 having one end connected to the connection point of the element SW2, a MOS • FET transistor FET3, FET2, a switch element SW4 having one end connected to the source S of the MOS • FET transistor FET2, FET4, and a MOS • FET transistor The switching element SW5 has one end connected to a connection point between the FET3 and the FET2, and is turned on and off by a switch command signal from the controller 23.
[0045]
The other ends of the switch elements SW1 to SW4 are connected to the detection unit 29, and the other end of the switch element SW5 is grounded via the constant current unit 31.
[0046]
These switch elements SW1 to SW5 operate as shown in FIG. 3 based on the switch command signal from the controller 23. In the measurement section (1), only the switch elements SW1 and SW4 are turned on with the timing shifted, and the others In the measurement period (2) to (4), only the switch elements SW2 and SW3 are turned on at different timings and the others are turned off. In the measurement period (3), the switch element SW2 is turned off. The switch element SW5 is also turned on together with the switch SW3.
[0047]
The detecting unit 29 inputs the drain D and source S voltages of the MOS-FET transistors FET1 to FET4 when the switch elements SW1 to SW5 are turned on, and obtains the Seebeck voltage, load voltage, Peltier voltage, and power supply voltage of the Peltier element 1. The measurement result is output and displayed on a display unit (not shown), and when the reference value or reference range is deviated from the reference value or reference range, an alarm signal is sent to the alarm unit 33 or It has a function to output to the display unit.
[0048]
That is, the detector 29 measures the voltages V1 and V4 (see FIG. 4) between the MOS and FET transistors FET1 and FET4 (between FET3 and FET2) in the measurement interval (1) in which the switch elements SW1 and SW4 are turned on. Then, Vc is calculated as Vc = V1−V4 using the measured voltages V1 and V4.
[0049]
In the measurement period {circle around (2)} in which the switch elements SW2 and SW3 are turned on, the both-end voltages V2 and V3 of the Peltier element 1 are input and measured, and the Seebeck voltage Vz is set to Vz using these measurement voltages V2 and V3 (see FIG. 4). = V2-V3 is calculated. Note that the sign of the Seebeck voltage Vz changes depending on the direction in which the drive current flows.
[0050]
In the measurement section {circle around (3)} in which the switch elements SW2, SW3 and SW5 are turned on, the measurement is carried out in the measurement section {circle around (2)} between the voltages V2 and V3 of the Peltier element 1 by the constant current Idc and the constant current Idc from the constant current section 31 The resistance value Rp of the Peltier device 1 is calculated from the Seebeck voltage Vz thus obtained based on the following equation.
Rp | {Vz− (V2−V3)} / Idc | However, absolute value
[0051]
In the measurement section (4) in which the switch elements SW2 and SW3 are turned on, the detection unit 29 inputs and measures the voltages V2 and V3 at both ends of the Peltier element 1, and uses these measurement voltages V2 and V3 to load the heat generation operation region. The voltage Vp is calculated by Vp = V2−V3, and the load voltage Vp in the endothermic operation region is calculated by Vp = V3−V2.
[0052]
Next, the operation of the above-described motion detection device according to the present invention will be briefly described.
First, a case where the temperature measurement value PV output from the input unit 5 to the controller 23 based on the measurement signal from the sensor 3 is lower than the set value SV and the Peltier element 1 is operated to generate heat will be described.
[0053]
In this case, the controller 23 performs a PID calculation based on the deviation between the temperature measurement value PV and the set value SV, and outputs a PWM signal (see FIG. 2C or D) based on a control output that reduces the deviation to the drive unit 9. Output.
[0054]
Since the drive unit 9 applies a switching signal to the gate circuits of the MOS • FET transistors FET1 and FET2, they are turned on, a drive current flows from the MOS • FET transistor FET1 to the FET2, and the Peltier device 1 is heated.
[0055]
In this heat generation operation state, the controller 23 outputs the switch command signal for each of the four measurement sections (1) to (4) for each cycle of the PWM signal and switches the switches SW1 to SW5 for the MOS / FET transistors FET1 and FET2. The detection unit 29 turns on and off, and the voltage Vc between the MOS / FET transistors FET1 and FET4 (between FET3 and FET2), the Seebeck voltage Vz of the Peltier element 1, and the Peltier element in the OFF period (1) to (3) of the PWM signal A resistance value Rp of 1 is detected, and a load voltage Vp in the heat generation operation region is detected in the on period (4) of the PWM signal.
[0056]
Next, a case where the temperature measurement value PV output from the input unit 5 to the controller 23 based on the measurement signal from the sensor 3 is higher than the set value SV and the Peltier element 1 is subjected to an endothermic operation will be described.
[0057]
In this case, the controller 23 outputs a PWM signal (see FIG. 2A or B) based on the control output so that the deviation between the temperature measurement value PV and the set value SV is small to the drive unit 9.
[0058]
Since the drive unit 9 applies a switching signal to the gate circuits of the MOS • FET transistors FET3 and FET4, they are turned on, a drive current flows from the MOS • FET transistor FET3 to the FET4, and the Peltier device 1 performs an endothermic operation.
[0059]
Even in this endothermic operation state, the controller 23 outputs the switch command signal for each of the four measurement sections {circle around (1)} to {circle around (4)} for each cycle of the PWM signal for the MOS / FET transistors FET3 and FET4. And the detection unit 29 detects the voltage Vc between the MOS / FET transistors FET1 and FET4 (between FET3 and FET2), the Seebeck voltage Vz of the Peltier element 1, and the Peltier in the OFF period (1) to (3) of the PWM signal. The resistance value Rp of the element 1 is detected, and the load voltage Vp in the heat generation operation region is detected in the ON period (4) of the PWM signal.
[0060]
The detection unit 29 outputs an alarm signal to the alarm unit 33 when the voltage Vc, the Seebeck voltage Vz, the resistance value Rp of the Peltier element 1 and the load voltage Vp deviate from a preset reference value or reference range. These are displayed and output to a display unit (not shown).
[0061]
In such a Peltier element operation detecting device according to the present invention, the H bridge circuit 11 is formed by a plurality of MOS FET transistors FET1 to FET4 each having a gate circuit to which a switching signal based on a PWM signal is applied. The Peltier element 1 is connected between the FET transistors FET1 to FET4, and the MOS / FET transistors FET1 to FET4 are switched and energized to change the direction of the drive current flowing to the Peltier element 1, while the MOS transistors The FET transistors FET1 to FET4 are connected to a switch unit 27 composed of switches SW1 to SW5, and during the heat generation operation or heat absorption operation, the measurement period {circle around (1)} is divided into four sections during one period of the PWM signal. These switches SW1 to SW4 W5 is controlled to switch, and the detection unit 29 determines the power source voltage Vc and the Peltier element 1 Seebeck from the terminal voltages V1 to V4 of the MOS-FET transistors FET1 to FET4 inputted in the OFF period (1) to (3) of the PWM signal. The voltage Vz and the resistance value Rp of the Peltier element 1 are detected, and the load voltage Vp in the heat generation operation region or the heat absorption operation region is detected in the ON period (4) of the PWM signal.
[0062]
Therefore, in the present invention, even when the Peltier element 1 is in the heating or heat absorption operation, the Seebeck voltage associated with the Seebeck effect of the Peltier element 1 is accurately detected using the off interval of the binary switching signal based on the PWM signal. Since it is possible to detect an abnormality in the temperature difference between the heat absorption surface and the heat generation surface of the Peltier element 1, it is possible to prevent thermal runaway.
[0063]
Further, since the load voltage of the Peltier element 1 can be measured even when the Peltier element 1 is generating heat or absorbing heat, the overvoltage applied to the Peltier element 1 can be discriminated, and the appropriate operation state of the Peltier element 1 can be determined. It can be secured.
[0064]
Furthermore, since the resistance Rp of the Peltier element 1 can be detected, it is possible to detect the deterioration of the Peltier element 1, and it is possible to ensure an appropriate operating state of the Peltier element 1 and extend its life.
[0065]
Furthermore, it becomes possible to detect the driving current flowing through the Peltier element 1 from the load voltage and resistance Rp of the Peltier element 1, and for example, even when a plurality of Peltier elements 1 are connected in parallel, There is an advantage that it is easy to find a malfunction.
[0066]
Since power supply voltage can also be detected, power supply voltage diagnosis can be performed when the power is turned on, and comparison diagnosis between the power supply voltage and the allowable voltage of the Peltier element can be performed when the power is turned on, thereby preventing thermal runaway caused by that. it can.
[0067]
In the above-described Peltier element operation detection device according to the present invention, during the heat generation operation or the heat absorption operation, one period of the PWM signal is divided into four measurement sections (1) to (4), and the PWM signal off section ▲ 1 to 3 detects the power supply voltage Vc between the MOS / FET transistors FET1 and FET4 (between FET3 and FET2), the Seebeck voltage Vz of the Peltier element 1, and the resistance value Rp of the Peltier element 1, and the on period of the PWM signal In (4), the load voltage Vp in the heat generation operation region or the heat absorption operation region is detected, but the present invention is not limited to this.
[0068]
That is, in the present invention, the measurement interval {circle around (2)} relating to one cycle of the PWM signal is set as the first off interval, and at least the Seebeck voltage Vz of the Peltier element 1 of the PWM signal can be detected in the first off interval. If it is constituted, the practicality as a product increases.
[0069]
Further, in the present invention, the measurement interval (4) relating to the one cycle is set as the ON interval, and the load voltage at both ends of the Peltier element 1 in the ON interval of the PWM signal is detected in the ON interval. The section (3) is set as the second off section, and the resistance value Rp of the Peltier element 1 is detected in the second off section, and the measurement section (1) for one cycle is set as the third off section. A function for detecting the power supply voltage in the off section 3 is added, and the controller 23 is formed in accordance with this function to control the switching of the switch unit 27, and the detection unit 29 may be formed.
[0070]
Furthermore, the present invention is not limited to the configuration in which the above-described (1) to (4) measurement sections are divided in each period, (1) the measurement section is assigned to a certain period, and (2) the measurement section is It is possible to have a configuration in which (3) measurement interval is assigned to the next cycle, and (1) to (4) measurement intervals are divided or assigned together for each skipping cycle. It is. In short, the object of the present invention can be achieved if it is assigned within a certain period.
[0071]
In the above-described embodiment, the H-bridge circuit 11 is formed by using the P-channel MOS • FET transistors FET1 and FET3 and the N-channel MOS • FET transistors FET2 and FET4. It is not limited.
[0072]
For example, as shown in FIG. 5, the P-channel MOS • FET transistors FET1 and FET3 are replaced with N-channel MOS • FET transistors FET5 and FET6. In each N-channel MOS • FET transistor FET2, FET4, FET5, and FET6, the switching signal is changed. Connections are made to be applied to the gate circuits of the N-channel MOS / FET transistors FET2 and FET4 to FET6 through the resistor R1, and the sources (S) of the N-channel MOS / FET transistors FET2 and FET4 to FET6 are returned. It is also possible to configure the H bridge circuit 35 by making a regression connection to the gate (G) side (or the previous stage side) via the line F.
[0073]
5 denotes a bias resistor connected between the gate (G) and the return line F in order to apply a bias to the gate circuit of each N-channel MOS • FET transistor FET2, FET4 to FET6. In the drawing, the drive unit 9 and the switch unit 27 are not shown.
[0074]
In this way, when the H bridge circuit 35 is formed of only the N-channel MOS / FET transistors FET2 and FET4 to FET6, the current flowing through the gate circuits of the N-channel MOS / FET transistors FET2 and FET4 to FET6 passes through the return line F. It returns to the previous stage and does not affect the drive current flowing from the power source + Vc to the N-channel MOS • FET transistors FET2, FET4 to FET6, and any gate voltage in each N-channel MOS • FET transistor FET2, FET4 to FET6. Can be applied, eliminating the need to use a high level gate voltage.
[0075]
That is, the floating drive of the N-channel MOS / FET transistors FET2, FET4 to FET6 becomes possible.
[0076]
Thus, the P-channel MOS • FET transistors are not used as shown in FIG. 4, and the N-channel MOS • FET transistors FET2 and FET4 to FET6 are arranged on both the high level side and the low level side of the Peltier element 1 as a load. Therefore, the H-bridge circuit 35 can be formed only by the N-channel MOS / FET transistors FET2 and FET4 to FET6.
[0077]
Therefore, the H-bridge circuit 35 can be formed using only the N-channel MOS • FET transistors FET2, FET4 to FET6, which have extremely low loss resistance during ON conduction as compared with the P-channel MOS • FET transistor. The heat generation of the N-channel MOS / FET transistors FET2, FET4 to FET6 itself can be reduced, and the space for arranging them can be reduced or downsized.
[0078]
【The invention's effect】
As described above, the temperature control device according to the present invention forms an H-bridge circuit with a plurality of MOS / FET transistors having a gate circuit to which a switching signal based on a PWM signal is applied, and is connected between the MOS / FET transistors. The direction of the drive current to be supplied to the Peltier element is switched by the H bridge circuit to cause a heat generation operation or a heat absorption operation, and during the heat generation operation or the heat absorption operation, Since the detection unit detects the Seebeck voltage of the Peltier element from the input potential in the first off section by switching the potential, it is possible to detect the Seebeck voltage of the Peltier element during the operation of the Peltier element. The operating state of the Peltier element by the detected Seebeck voltage while operating the Peltier element, in particular, The expected or detecting the occurrence of runaway becomes possible.
The switch part is formed so as to have a function of switching and inputting the potential of the Peltier element in the ON period of the PWM signal during the heat generation operation or the heat absorption operation, and the load voltage of the Peltier element is determined from the input ON period potential. In the configuration in which the detection unit is provided with a function of detecting the operation state, the operating state of the Peltier element can be grasped from the detected load voltage at both ends of the Peltier element, and an appropriate drive voltage can be applied.
In addition, a function of switching and inputting the potential of the Peltier element in a second off period that is different from the first off period of the PWM signal at the time of heat generation operation or heat absorption operation, and a predetermined value for the Peltier element in the second off period In the configuration in which the switch unit is formed so as to have a function of switching and inputting a constant current, and the function of detecting the resistance of the Peltier element from the inputted potential and constant current of the second ON section is provided in the detection unit. The operating state of the Peltier element, in particular, the deterioration state of the Peltier element can be grasped, and appropriate heating or cooling control can be ensured.
Further, in a third off section that is different from the first and second off sections of the PWM signal during the heat generation operation or the heat absorption operation, the power supply voltage applied to the H bridge circuit is switched and input during the third off section. In the configuration in which the switch part is formed so as to have a function to detect and the input power supply voltage is provided in the detection part, power supply voltage diagnosis at power-on is possible and operation of the Peltier element is allowed. Comparison with the drive voltage becomes possible, and deterioration of the Peltier element can be suppressed.
Furthermore, an N-bridge MOS / FET transistor is combined to form an H-bridge circuit, and the MOS / FET transistor is set so that the signal flowing through the gate circuit of each MOS / FET transistor is returned to the previous stage via a return line. The connection configuration has an advantage that the loss at the time of ON conduction in the H bridge circuit can be reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a motion detection apparatus according to the present invention.
2 is a waveform diagram showing a PWM signal from a controller in FIG. 1. FIG.
FIG. 3 is a waveform diagram for explaining the operation of the motion detection apparatus according to FIG. 1;
4 is a circuit diagram illustrating a configuration example of an H-bridge circuit and a switch unit in FIG. 1. FIG.
FIG. 5 is a circuit diagram showing another configuration example of the H-bridge circuit in the present invention.
FIG. 6 is a block diagram showing a temperature control device using a conventional Peltier element.
FIG. 7 is a waveform diagram for explaining a heat generation operation and a heat absorption operation of a Peltier element by an H bridge circuit.
FIG. 8 is a diagram showing a heating or cooling system using a temperature control device for a Peltier element.
FIG. 9 is a characteristic diagram showing the relationship between the drive current and the endothermic flow exhibited by the Peltier element.
[Explanation of symbols]
1 Peltier element
3 Sensor
5 Input section
7, 23 Controller
9 Drive section
11, 35 H bridge circuit
13 Heat load
15 heat exchanger
17 tanks
19 Pump
21 Pipe
25 Power supply
27 Switch part
29 Detector
31 Constant current section
33 Alarm section
F Return
FET1, FET3 P-channel MOS / FET transistor
FET2, FET4, FET5, FET6 N-channel MOS / FET transistor
R1, R2 resistance
SW1, SW2, SW3, SW4, SW5 Switch element
Vc power supply

Claims (5)

A Peltier element that generates heat or absorbs heat depending on the direction of the drive current to flow;
An H-bridge circuit having a plurality of MOS-FET transistors having a gate circuit to which a switching signal based on a PWM signal is applied, and for switching the direction of the drive current flowing to the Peltier element connected between the MOS-FET transistors; ,
A switch unit for switching and inputting the potential of the Peltier element in a first OFF section in the PWM signal during the heat generation operation or the heat absorption operation;
A detection unit for detecting the Seebeck voltage of the Peltier element from the input potential of the off interval;
An apparatus for detecting the operation of a Peltier element. The switch unit has a function of switching and inputting the potential of the Peltier element in the ON section during the fixed period during the heat generation operation or the heat absorption operation, and the detection unit is input with the potential of the ON section The operation detection device for a Peltier element according to claim 1, having a function of detecting a load voltage of the Peltier element. The switch unit is configured to switch and input the potential of the Peltier element in a second off period that is different from the first off period in the fixed period during the heat generation operation or the heat absorption operation; And having a function of switching and inputting a predetermined constant current to the Peltier element during the off-period, and the detection unit detects the resistance of the Peltier element from the input potential and the constant current of the second on-period The operation detecting device for a Peltier element according to claim 1 or 2, which has a function of: The switch unit switches a power supply voltage applied to the H-bridge circuit in a third off period that is different from the first and second off periods in the fixed period during the heat generation operation or the heat absorption operation. The Peltier element operation detection device according to claim 1, further comprising an input function, wherein the detection unit has a function of detecting the input power supply voltage. The H-bridge circuit is a combination of N-channel MOS / FET transistors, and the MOS / FET transistors are connected so that signals flowing through the gate circuits of the MOS / FET transistors are returned to the previous stage via a return line. The operation detection device for a Peltier element according to any one of claims 1 to 4.

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