JP2011192756A - Electronic apparatus with waste heat power generation function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive electronic apparatus with waste heat power generation function, which efficiently collects heat, generates power as a whole, effectively uses power obtained by waste heat power generation and has a simple structure. <P>SOLUTION: The electronic apparatus (10) with waste heat power generation function includes a cooling device (80) for cooling an electric component (14), an electrothermal converter (24) for converting heat of the electric component (14) into voltage, converters (52, 62) converting voltage which the electrothermal converter (24) outputs into a reproduced voltage of DC at a variable transformation ratio, a power supply selection circuit (70) to which the reproduced voltage which the converters (52, 62) output and the power supply voltage of DC, which an external power supply (72) outputs, are input, and outputs power based on the reproduced voltage when a voltage level of the reproduced voltage is larger than that of the power supply voltage, and a controller (60) controlling the voltage level of the reproduced voltage by adjusting cooling performance of a cooling device (80) so that the voltage level of the reproduced voltage becomes larger than that of the power supply voltage. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic device having a waste heat power generation function.

Electronic devices such as personal computers and switching hubs have a circuit board arranged in a housing, and a large number of electrical components such as an LSI chip constituting a CPU (Central Processing Unit) are mounted on the circuit board. Yes. Since the electrical component generates a large amount of heat as the electronic device operates, the electronic device is provided with an air cooling fan together with a heat sink in order to protect the LSI chip from heat.
And since the heat | fever discharged | emitted by the fan outside of the housing | casing raises the temperature around an electronic device, the air conditioning apparatus is also provided in the space where many electronic devices are installed.

Thus, in the conventional electronic device, electric power is required to process the generated heat, and a large amount of electric power is consumed with the operation of the electronic device. Therefore, in recent years, harvester technology (waste heat power generation technology) has been developed that generates power using heat generated by electrical components and uses the obtained power as a power source.
For example, in the thermal energy regeneration device disclosed in Patent Document 1, a thermoelectric conversion element is attached to a heat generating element, and an internal power regeneration circuit supplies and supplies internal power obtained from the thermoelectric conversion element as a power source.

  More specifically, the internal power regeneration circuit is provided with a power storage unit, a voltage determination unit, and a control device, accumulates charges flowing in from the thermoelectric conversion elements in the power storage unit, and stores the charge in the power storage unit in the voltage determination unit. The control device determines whether or not the voltage is equal to or higher than a predetermined threshold value, and the control device determines whether the power storage unit and the power supply circuit are connected, the power supply circuit and the external power source or the secondary battery according to the determination result by the voltage determination unit. Control to switch the connection state in a contradictory manner is performed.

  The power supply circuit has switching means such as a power transistor between the input terminal for connecting the external power supply and the output terminal connected to the electronic element of each circuit block, and is controlled by the control device for the internal power regeneration circuit. The switching means is on / off controlled by the signal.

JP 2001-308395 A

However, the thermal energy regeneration device disclosed in Patent Document 1 described above has a power storage unit in the internal power regeneration circuit, and the configuration is complicated. For this reason, when this thermal energy regeneration device is adopted, there is a risk of increasing the size and price of electronic equipment.
Therefore, a power supply selection circuit that omits the power storage unit and outputs one input voltage according to the magnitude relationship between the two input voltages, that is, the voltage from the power supply (power supply voltage) and the voltage obtained by thermoelectric conversion (regenerative voltage). Can be considered.

  In this case, by keeping the regeneration voltage higher than the power supply voltage, it is required to preferentially use the power obtained by thermoelectric conversion in order to efficiently use the power obtained by waste heat power generation as a whole. The

  The present invention has been made in view of the above-described circumstances, and its object is to recover heat efficiently and generate electric power as a whole, and to use electric power obtained by waste heat power generation effectively and without waste. An object of the present invention is to provide an inexpensive electronic device with a waste heat power generation function.

  In order to achieve the above object, according to one aspect of the present invention, an electrical component mounted on a circuit board and generating heat when energized, a cooling device for cooling the electrical component, and heat generated by the electrical component are generated. A thermoelectric converter that converts the voltage into voltage, a converter that outputs the voltage output from the thermoelectric converter, converts the input voltage to a DC regenerative voltage with a variable transformation ratio, and outputs a DC power supply voltage. An external power supply to be output, a regeneration voltage output from the converter and a power supply voltage output from the external power supply are input, and when the voltage level of the regeneration voltage is higher than the voltage level of the power supply voltage, the regeneration voltage is set. A power source selection circuit that outputs electric power based on the power source, and the cooling power of the cooling device is adjusted to control the voltage level of the regenerative voltage so that the voltage level of the regenerative voltage is higher than the level of the power supply voltage. Cogeneration function-equipped electronic apparatus, characterized in that it comprises a control device for there is provided (claim 1).

According to the electronic device with a waste heat power generation function of the first aspect, the regeneration voltage and the power supply voltage are input to the power supply selection circuit.
The power supply selection circuit outputs power based on the reproduction voltage when the voltage level (absolute value) of the reproduction voltage is higher than the voltage level of the power supply voltage. Then, the control device controls the voltage level of the reproduction voltage so that the voltage level of the reproduction voltage is higher than the voltage level of the power supply voltage. With this control, when the voltage level of the reproduction voltage becomes higher than the voltage level of the power supply voltage, the power selection circuit outputs power based on the reproduction voltage. That is, the control device preferentially outputs power based on the reproduction voltage from the power supply selection circuit.

Then, the control device controls the voltage level of the regeneration voltage by adjusting the cooling capacity of the cooling device. Specifically, when the voltage level of the regeneration voltage is increased, the cooling capacity is decreased.
Therefore, in this electronic device with waste heat power generation function, the power consumption of the cooling device is suppressed, so that the heat is efficiently recovered and converted into electric power as a whole, and the obtained electric power is effectively used without waste. Is done. As a result, in the electronic apparatus with a waste heat power generation function, energy consumption is reduced with a simple configuration.

Preferably, the control device further adjusts a transformation ratio of the converter in order to control a voltage level of the regeneration voltage (Claim 2).
In the electronic device with a waste heat power generation function according to the second aspect, the control device further adjusts the transformation ratio, whereby the voltage level of the regenerative voltage is accurately controlled with a simple configuration.

Preferably, when the voltage level of the regeneration voltage is increased, the control device gives priority to reducing the cooling capacity of the cooling device rather than reducing the transformation ratio (claim 3).
In the electronic apparatus with a waste heat power generation function according to the third aspect, priority is given to reducing the cooling capacity, so that more heat is converted into electricity, and energy consumption is further reduced.

Preferably, when the voltage level of the regenerative voltage is decreased, the control device gives priority to increasing the transformation ratio rather than increasing the cooling capacity of the cooling device (claim 4).
In the electronic device with a waste heat power generation function according to claim 4, more heat is converted into electricity by further prioritizing increasing the transformation ratio than increasing the cooling capacity, and further reducing energy consumption. Is done.

  According to the present invention, an inexpensive electronic device with a waste heat power generation function of a simple configuration that efficiently recovers heat as a whole and generates power and effectively uses the power obtained by waste heat power generation without waste is provided. Is done.

It is a block diagram which shows the schematic structure of the electronic device with a waste heat power generation function of one Embodiment. FIG. 2 is a cross-sectional view schematically showing a connection configuration between an LSI chip and a thermoelectric converter in the electronic apparatus with a waste heat power generation function of FIG. It is sectional drawing which shows schematically the structure of the thermoelectric converter applied to the electronic device with a waste heat power generation function of FIG. It is a block diagram which shows schematic structure of the level converter applied to the electronic device with a waste heat power generation function of FIG. It is a block diagram which shows the schematic structure of the converter applied to the electronic device with a waste heat power generation function of FIG. It is a block diagram which shows the schematic structure of the diode OR circuit applied to the electronic device with a waste heat power generation function of FIG. 6 is a schematic chart for explaining an output of a bridge circuit of the converter of FIG. 5. It is a schematic chart for demonstrating the output of the converter of FIG. It is a schematic flowchart of the program which the control apparatus applied to the electronic device with a waste heat power generation function of FIG. It is sectional drawing which shows schematically the structure of the thermoelectric converter of a modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram schematically illustrating a configuration of an electronic device 10 with a waste heat power generation function according to an embodiment.
The electronic device 10 with a waste heat power generation function is, for example, a switching hub, and includes a main circuit board 12 disposed in a housing 11. On the main circuit board 12, an LSI chip 14 and an interface 16 functioning as a CPU (Central Processing Unit) are mounted. The interface 16 is connected to the LSI chip 14 and has a plurality of ports opened to the outside.

  A plurality of networks 18a, 18b, 18c, 18d, 18e, and 18f are connected to a plurality of ports of the interface 16 via cables. The LSI chip 14 controls data exchange between the networks 18a, 18b, 18c, 18d, 18e, and 18f, which is the main function of the electronic apparatus 10 with a waste heat power generation function. Hereinafter, the networks 18a, 18b, 18c, 18d, 18e, and 18f are collectively referred to simply as the network 18.

A heat sink 20 is attached to the LSI chip 14, and one end of a heat pipe 22 is connected to the heat sink 20. The other end side of the heat pipe 22 is connected to the thermoelectric converter 24.
More specifically, as shown in FIG. 2, the heat sink 20 is attached to the upper surface of the LSI chip 14, and one end side of the heat pipe 22 is embedded in the base of the heat sink 20 on the LSI chip 14 side. The other end side of the heat pipe 22 is embedded in, for example, a flat rectangular parallelepiped metal block 26. A thermoelectric converter 24 is disposed on the block 26.
The heat pipe 22 is filled with a fluid for transferring heat.

  The thermoelectric converter 24 is not limited as long as it converts heat energy into electric energy. Preferably, the thermoelectric converter 24 is obtained by a Stirling engine 28 that converts heat energy into kinetic energy, as shown in FIG. And an electromagnetic induction unit 30 for converting the kinetic energy thus obtained into electrical energy.

  More specifically, the Stirling engine 28 is a free piston type and has a base 32 disposed on the block 26. A recess 32a is formed at the center of the upper surface of the base 32, and a spring member 33 having a cross-sectional shape, for example, is disposed on the upper surface of the base 32 so as to cover the recess 32a.

  The lower end of the first cylinder 34 is fixed to the base 32 so as to surround the spring member 33 in an airtight manner. A second cylinder 36 having a smaller diameter than the first cylinder 34 is coaxially connected to the upper end of the first cylinder 34, and the second cylinder 36 is airtight at the upper end of the second cylinder 36. A cap 38 is attached.

  However, a through hole is formed in the cap 38, and the rod 40 extends vertically through the through hole. The rod 40 passes through a cylindrical output piston 42 that is concentrically arranged in the second cylinder 36 so as to be movable up and down, and the output piston 42 is fixed to the rod 40. The outer peripheral surface of the output piston 42 is in sliding contact with the inner peripheral surface of the second cylinder 36, and the output piston 42 hermetically partitions the upper end side and the lower end side of the second cylinder 36.

The rod 40 passes through a columnar displacer 44 that is concentrically arranged in the first cylinder 34 so as to be movable up and down. However, the displacer 44 is not fixed to the rod 40 and is relatively displaced. Is possible. There is a gap between the displacer 44 and the first cylinder 34.
The first cylinder 34 and the second cylinder 36 are filled with working gas.

The electromagnetic induction unit 30 includes a magnet 46 fixed to the upper end of the rod 40 and a coil 48 provided so as to surround the magnet 46. The N magnetism and the S pole of the magnet 46 are separated in the longitudinal direction of the rod 40.
An elastic member 50 formed by bending a belt-like plate is provided between the cap 38 and the magnet 46.

The coil 48 of the electromagnetic induction unit 30 is connected to the level converter 52. As shown in FIG. 4, the level converter 52 includes a primary coil 54 to which an output from the coil 48 is input, and a secondary that generates an electromotive force based on a change in magnetic flux generated in the primary coil 54. Side coil 56.
The secondary coil 56 has, for example, two connection terminals (taps) in addition to both ends, and one end and the two connection terminals of the secondary coil 56 are alternatively connected to the ground by a switch 58.

The switch 58 operates in accordance with a command from the control device 60, and the effective number of turns of the secondary coil 56 changes according to the state of the switch 58. The control device 60 can be configured by an LSI chip having a function as a CPU (Central Processing Unit).
Therefore, in this embodiment, when the input voltage of the primary coil 54 is V1 and the output voltage of the secondary coil 56 is V2, the transformation ratio (V1 / V2) can be switched in three stages. . In FIG. 4, the number of turns is indicated as N, (N−j), and (N−k).

The output voltage V2 of the secondary coil 56 is input to the converter 62. The converter 62 outputs the output voltage V2 of the secondary coil 56 as a DC voltage.
For example, as shown in FIG. 5, the converter 62 includes a full-wave rectifier circuit configured by a bridge circuit 64 including a diode, a smoothing circuit configured by a capacitor 66, and a filter (stabilization circuit) 68. . The capacitor 66 is inserted in parallel with the output terminal of the bridge circuit 64, and the filter 68 is connected to one output terminal of the bridge circuit 64 in series downstream of the capacitor 66.

As shown in FIG. 6, the output voltage of the converter 62 is input to a diode OR circuit 70 serving as a power supply selection circuit.
On the other hand, the electronic apparatus 10 with a waste heat power generation function has an external power supply 72, and a DC voltage (power supply voltage Vdc) output from the external power supply 72 is also input to the diode OR circuit 70. The power supply voltage Vdc is −48V, for example.
Diode OR circuit 70 includes a diode 74 connected in series to one of the output terminals of converter 62 and a diode 76 connected in series to one of the output terminals for diode OR circuit 70 of external power supply 72.

The output of the diode OR circuit 70 is input to an insulation type DC-DC converter 78. Specifically, the output terminal of the diode 74 and the output terminal of the diode 76 are connected to one input terminal of the DC-DC converter 78 in parallel with each other. The DC-DC converter 78 converts the input voltage into a predetermined voltage and outputs it.
Note that the output voltage Vcon (t) of the converter 62 and the power supply voltage Vdc of the external power supply 72 are monitored by the control device 60.

The external power source 72 also has an output terminal for the fan 80 and supplies power to the fan 80. The fan 80 generates an air flow that flows in the vicinity of the LSI chip 14 and can cool the LSI chip 14 by air. The rotational speed of the fan 80 is controlled by the control device 60.
Referring to FIG. 1 again, the level converter 52, the control device 60, the converter 62, the diode OR circuit 70, and the DC-DC converter 78 are different from the main circuit board 12 disposed in the housing 11. It is mounted on the sub circuit board 82. The output of the DC-DC converter 78 is supplied to the power input terminal of the main circuit board 12 and then supplied to, for example, an electrical component such as the LSI chip 14.

Hereinafter, the operation of waste heat power generation in the electronic device 10 with the waste heat power generation function described above will be described.
When the electronic device 10 with a waste heat power generation function executes a data transfer operation between the networks 18 which is a main function, the LSI chip 14 generates heat by performing calculation by receiving power supply.

The heat generated in the LSI chip 14 is transmitted through the heat pipe 22 and supplied to the thermoelectric converter 24 via the block 26.
In the thermoelectric converter 24, the magnet 46 fixed to the upper end of the rod 40 reciprocates up and down by the supplied heat. An electromotive force is generated in the coil 48 by electromagnetic induction due to the reciprocation of the magnet 46.

The thermoelectric converter 24 outputs an alternating voltage generated in the coil 48 by the electromotive force, and the alternating voltage is input to the level converter 52. The level converter 52 appropriately converts the input AC voltage and outputs the AC voltage, and the output AC voltage is input to the converter 62.
In the converter 62, a rectified voltage obtained by inverting one polarity (plus) of the AC voltage as shown in FIG. The rectified voltage output from the bridge circuit 64 is smoothed by the capacitor 66 and then stabilized by the filter 68. As shown in FIG. 8, a substantially constant reproduction voltage Vcon (t) is output from the converter 62. Is done.

The reproduction voltage Vcon (t) output from the converter 62 is input to the diode OR circuit 70. In the diode OR circuit 70, the regenerative voltage Vcon ((con) is determined based on the magnitude relationship between the regenerative voltage Vcon (t) and the power supply voltage Vdc from two diodes 74 and 76 that are provided in parallel and whose output sides are connected to each other. One or both of t) and the power supply voltage Vdc are output.
Specifically, the two diodes 74 and 76 have the following unique characteristics (1) to (3) when α is a predetermined positive value (eigenvalue). The unit of the eigenvalue α is a volt, and in this embodiment, the eigenvalue α is 0.7 V or more, for example.

(1) The two diodes 74 and 76 have a voltage level (absolute value) of the reproduction voltage Vcon (t) that is equal to or higher than the sum (| Vdc | + α) of the voltage level of the power supply voltage Vdc and the eigenvalue α (| Vcon (t) | ≧ | Vdc | + α) and the reproduction voltage Vcon (t) are exclusively output.
(2) When the difference between the voltage level of the reproduction voltage Vcon (t) and the voltage level of the power supply voltage Vdc is smaller than the eigenvalue α (| Vcon (t) | − | Vdc | <α ), Both the reproduction voltage Vcon (t) and the power supply voltage Vdc are output equally.
(3) When the voltage level of the external voltage Vdc is equal to or higher than the sum of the voltage level of the reproduction voltage Vcon (t) and the eigenvalue α (| Vcon (t) | + α), the two diodes 74 and 76 (| Vcon (T) | + α) ≦ | Vdc |), the power supply voltage Vdc is exclusively output.

  When one or both of the reproduction voltage Vcon (t) and the power supply voltage Vdc is input to the DC-DC converter 78 based on the unique characteristics of the above (1) to (3), the DC-DC converter 78 The input voltage is converted to output a DC voltage of, for example, 5V. The output of the DC-DC converter 78 is supplied to the LSI chip 14 and the like mounted on the main circuit board 12.

Here, FIG. 9 is a flowchart schematically showing a main program executed by the control device 60.
According to the main program, first, the voltage level of the reproduction voltage Vcon (t) that is the monitoring target (control amount) is read (step 10), and the voltage level of the read reproduction voltage Vcon (t) is DC-DC. It is determined whether the rated input value of converter 78 is greater than maximum value Vmax (step 12). If the result of determination in step 12 is that the voltage level of the reproduction voltage Vcon (t) is greater than the maximum value Vmax (in the case of Yes), whether or not the transformation ratio (V1 / V2) of the level converter 52 is maximum. Is confirmed (step 14).

  If the result of determination in step 14 is that the transformation ratio (V1 / V2) is not maximum (in the case of No), the control device 60 operates the switch 58 to increase the transformation ratio (V1 / V2) by one step (step 16). ). On the other hand, if the result of determination in step 14 is that the transformation ratio (V1 / V2) is maximum (in the case of Yes), the control device 60 increases the rotational speed of the fan 80 by a predetermined number (step 18). Then, after step 16 or step 18, step 10 is executed, and the voltage level of the reproduction voltage Vcon (t) is read again.

  If the result of determination in step 12 is that the voltage level of the reproduction voltage Vcon (t) is not greater than the maximum value Vmax (in the case of No), the voltage level of the reproduction voltage Vcon (t) is equal to the voltage level of the power supply voltage Vdc and the eigenvalue. It is determined whether or not the sum is greater than or equal to (| Vdc | + α) (step 20). If the result of determination in step 20 is that the voltage level of the reproduction voltage Vcon (t) is equal to or greater than the sum (| Vdc | + α) of the voltage level of the power supply voltage Vdc and the eigenvalue α (in the case of Yes), step 10 is executed. Then, the voltage level of the reproduction voltage Vcon (t) is read again.

  If the result of determination in step 20 is that the voltage level of the reproduction voltage Vcon (t) is not equal to or higher than the sum (| Vdc | + α) of the voltage level of the power supply voltage Vdc and the eigenvalue α (in the case of No), the rotation of the fan 80 It is confirmed whether or not the number is minimum (step 22).

  If the result of determination in step 22 is that the rotation speed of the fan 80 is minimum (in the case of Yes), the control device 60 operates the switch 58 to decrease the transformation ratio (V1 / V2) by one step (step 24). On the other hand, if the result of determination in step 22 is that the rotational speed of the fan 80 is not minimum (in the case of No), the controller 60 decreases the rotational speed of the fan 80 by a predetermined number (step 26). Then, after step 24 or step 26, step 10 is executed, and the voltage level of the reproduction voltage Vcon (t) is read again.

  In the electronic apparatus 10 with a waste heat power generation function of the embodiment described above, the regeneration voltage Vcon (t) and the power supply voltage Vdc are input to the diode OR circuit 70. Since the diode OR circuit 70 exhibits the above characteristics (1) to (3), the electronic apparatus 10 with a waste heat power generation function may not have a power storage unit that stores the regenerative voltage Vcon (t). The reproduction voltage Vcon (t) is often used with a simple configuration.

  On the other hand, in this electronic apparatus 10 with a waste heat power generation function, the control device 60 causes the regeneration voltage Vcon (t) to be equal to or higher than the sum of the voltage level of the power supply voltage Vdc and the eigenvalue α. Control the voltage level of t). With this control, when the voltage level of the reproduction voltage Vcon (t) becomes equal to or higher than the sum of the voltage level of the power supply voltage Vdc and the eigenvalue α, the diode OR circuit 70 outputs power based on the reproduction voltage Vcon (t). . That is, the control device 60 preferentially outputs power based on the reproduction voltage Vcon (t) from the diode OR circuit 70. As a result, in the electronic apparatus 10 with a waste heat power generation function, the use of the external power source 72 is suppressed, and the regeneration voltage Vcon (t) is effectively used, and the energy consumption is reduced as a whole.

And in the electronic device 10 with a waste heat power generation function of one Embodiment mentioned above, when the control apparatus 60 makes the rotation speed of the fan 80 low, the heat | fever provided for electric power generation increases, With simple structure, The voltage level of the reproduction voltage Vcon (t) increases.
Further, in the electronic apparatus 10 with the waste heat power generation function of the above-described embodiment, the control device 60 reduces the transformation ratio (V1 / V2), so that the voltage of the reproduction voltage Vcon (t) can be obtained with a simple configuration. The level becomes higher.
When the voltage level of the regeneration voltage Vcon (t) is increased, first, the rotational speed of the fan 80 is set from the viewpoint of increasing the power output from the thermoelectric converter 24 and reducing the power consumption of the fan 80. Lowering is preferable.

  Furthermore, in the electronic apparatus 10 with the waste heat power generation function of the above-described embodiment, the control device 60 controls the voltage level of the regeneration voltage Vcon (t) even if the rated input voltage of the DC-DC converter has an upper limit. This prevents the reproduction voltage Vcon (t) exceeding the upper limit from being input to the DC-DC converter. For this reason, the electronic apparatus 10 with a waste heat power generation function operates stably.

  Specifically, the voltage level of the reproduction voltage Vcon (t) can be lowered by increasing the transformation ratio (V1 / V2) of the level converter 52 or increasing the rotational speed of the fan 80. When the voltage level of the regeneration voltage Vcon (t) is lowered, the rotation speed of the fan 80 is increased from the viewpoint of preventing an increase in power consumption of the fan 80 while maintaining the power output from the thermoelectric converter 24. It is preferable to increase the transformation ratio (V1 / V2) of the level converter 52 before making it.

  Furthermore, in the electronic apparatus 10 with the waste heat power generation function of the above-described embodiment, by using the Stirling engine 28 and the electromagnetic induction unit 30, the conversion efficiency from heat to electricity is increased, and the energy consumption is further reduced. The

The present invention is not limited to the above-described embodiment, and includes a form obtained by modifying the above-described embodiment.
For example, in the above-described embodiment, the thermoelectric converter 24 includes the Stirling engine 28 and the electromagnetic induction unit 30. However, as illustrated in FIG. 10, the thermoelectric converter 84 using the Seebeck effect may be used. Good.

The thermoelectric converter 84 has a QW (quantum well structure) film 86 of Si / SiGe as a p-type semiconductor and a QW film 88 of B4C / B9C as an n-type semiconductor, and the QW film 86 and the QW film 88 By applying heat to the joint portion, electromotive force is generated at both ends of the QW film 86 and the QW film 88.
The electromotive force generated by the thermoelectric converter 84 is input to an inverting DC-DC converter 90 that serves as both a level converter and a converter, and the regenerative voltage Vcon (t) is input to the diode OR circuit 70.

  In the above-described embodiment, the diode OR circuit 70 and the DC-DC converter 78 are mounted on the sub circuit board 82, but the diode OR circuit 70 and the DC-DC converter 78 are mounted on the main circuit board 12. Also good. Further, the level converter 52, the converter 62, and the control device 60 may be mounted on the main circuit board 12.

  In the above-described embodiment, the LSI chip 14 is air-cooled by the fan 80, but may be water-cooled or may be cooled by a Peltier element. In these cases, the control device 60 may adjust the rotation speed of the pump for water cooling and the voltage applied to the Peltier element instead of the rotation speed of the fan 80 in order to adjust the cooling capacity.

In the above-described embodiment, the diode OR circuit 70 is employed as the power supply selection circuit. However, a power supply selection circuit that outputs the larger one of the input reproduction voltage and power supply voltage is used. Also good. Another electric circuit such as a switch circuit may be employed as the power source selection circuit.
In the above-described embodiment, the level converter 52 and the converter 62 cooperate to constitute a converter that converts the output voltage of the thermoelectric converter 24 into the DC regenerative voltage Vcon (t). -Like DC converter 90, the structure of a converter is not specifically limited.

In the above-described embodiment, the heat of the LSI chip 14 is converted into electricity, but the heat of other electric components may be converted into electricity.
Finally, it goes without saying that the present invention is applicable to electronic devices such as personal computers other than the switching hub.

10 Electronic Equipment with Waste Heat Power Generation Function 12 Main Circuit Board 14 LSI Chip (Electric Components)
16 Interface 18 Network 20 Heat sink 22 Heat pipe 24, 84 Thermoelectric converter 28 Stirling engine 30 Electromagnetic induction unit 52 Level converter (converter)
60 control device 62 converter (converter)
70 Diode OR circuit (power supply selection circuit)
72 External power supply 78 Isolated DC-DC converter 80 Fan (cooling device)

Claims (4)

Electrical components mounted on a circuit board that generate heat when energized;
A cooling device for cooling the electrical component;
A thermoelectric converter that converts heat generated in the electrical component into a voltage;
The converter outputs the voltage output from the thermoelectric converter, converts the input voltage into a DC regeneration voltage with a variable transformation ratio, and
An external power supply that outputs a DC power supply voltage;
A power supply that receives the regenerative voltage output from the converter and the power supply voltage output from the external power supply, and outputs power based on the regenerative voltage when the voltage level of the regenerative voltage is greater than the voltage level of the power supply voltage A selection circuit;
A waste heat power generation system comprising: a control device configured to control a voltage level of the regeneration voltage by adjusting a cooling capacity of the cooling device so that a voltage level of the regeneration voltage is higher than the power supply voltage level. Functional electronic equipment.   The electronic device with a waste heat power generation function according to claim 1, wherein the control device further adjusts a transformation ratio of the converter to control a voltage level of the regeneration voltage.   3. The control device according to claim 2, wherein when the voltage level of the regeneration voltage is increased, the control device gives priority to reducing the cooling capacity of the cooling device rather than reducing the transformation ratio. Electronic equipment with waste heat power generation function.   The said control apparatus gives priority to making the said transformation ratio large rather than increasing the cooling capacity of the said cooling device, when decreasing the voltage level of the said regeneration voltage. Electronic equipment with waste heat power generation function described in 1.

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