JP6488785B2 - Wireless transmission device and wireless transmission system - Google Patents

Description

  The present invention relates to a wireless transmission device and a wireless transmission system, and more particularly, to a wireless transmission device and a wireless transmission system that use power supplied from a power generation element that generates power using mechanical energy input from the outside.

In recent years, by collecting and analyzing measurement data of various sensors (humidity sensor, temperature sensor, vibration sensor, gas concentration sensor, human sensor, acceleration sensor, CO ₂ sensor, etc.) by wireless transmission, various objects (equipment) , Building, environment, etc.) sensor network systems that perform state measurement, automatic control, etc. are being studied.

  Such a sensor network system includes a sensor, a wireless transmission device having a wireless transmission unit that wirelessly transmits measurement data acquired by the sensor, and a host computer that collects and analyzes the wirelessly transmitted measurement data. In general, the number of sensors used in a sensor network system is very large, and how to supply operating power necessary for wirelessly transmitting measurement data from each sensor to a wireless transmission unit is a problem in the sensor network system. Met.

  In order to solve such problems, it has been proposed to use an energy harvesting element that generates power using various mechanical energy (vibration, pressure, etc.) input from the outside. For example, the energy harvesting element disclosed in Patent Literature 1 is attached to a vibrating body such as an air conditioning duct in a building, and generates power using vibration energy input from the vibrating body.

  In general, since mechanical energy input from the outside to the energy harvesting element is very small, the power generated by the energy harvesting element is very small, and it is possible to secure operating power for driving the wireless transmission unit. Have difficulty. As a method for ensuring the operating power of the wireless transmission unit, a method for ensuring the operating power of the wireless transmission unit by boosting the power generated by the environmental power generation element by a boosting unit such as a DC-DC converter It has been known.

  Moreover, since the electric power generated by the energy harvesting element is very small as described above, it is required to reduce the electric power consumed unnecessarily due to factors other than wireless transmission. For example, a booster such as a DC-DC converter consumes standby power when in an ON state. In order to reduce such unnecessary power consumption, a wireless transmission device that performs ON / OFF control of a booster in synchronization with the wireless transmission operation of the wireless transmission unit is known (see, for example, Patent Document 2). ).

  FIG. 1 shows a wireless transmission configured to execute ON / OFF control of a booster unit in synchronization with the wireless transmission operation of the wireless transmitter unit by turning on the booster unit at a predetermined time interval using a timer. The device is shown. The timer counts a predetermined time interval using the power supplied from the power storage unit upstream of the booster unit, and turns on the booster unit at every predetermined time interval. Therefore, the booster can be turned on at the timing of executing the wireless transmission operation, and unnecessary power consumption due to standby power of the booster can be reduced.

  As described above, in order to turn on the boosting unit at predetermined time intervals using the timer, it is necessary to output a signal from the wireless transmission unit to the timer and reset the time count of the timer periodically. Generally, in order to reset the time count of the timer, the timer and the wireless transmission unit are connected so as to be able to execute serial communication, more specifically, I2C (Inter-Integrated Circuit) communication. However, the voltage necessary for driving the timer to be capable of I2C communication (I2C communication executable voltage) is relatively high, and in order to supply such a voltage to the timer, the voltage of the power storage unit in the previous stage of the boosting unit must be increased. Need to be maintained.

  In this case, in order to prevent the voltage of the power storage unit from dropping below the I2C communication executable voltage, it is necessary to set the drive voltage of the boosting unit to be equal to or higher than the I2C communication executable voltage. However, if the drive voltage of the booster is set high, the booster is not driven when the vibration (mechanical energy) input to the power generation element is weak, and as a result, the wireless transmitter 1 may not be driven. .

JP 2011-172352 A JP 2000-278199 A

  The present invention has been made in view of the above-described conventional problems, and its purpose is that the mechanical energy input to the power generation element is weak by configuring so that the output voltage of the booster can be supplied to the timer. An object of the present invention is to provide a wireless transmission device and a wireless transmission system that can be driven.

Such an object is achieved by the present inventions (1) to (6) below.
(1) A wireless transmission device that uses power supplied from a power generation element that generates power using mechanical energy input from the outside,
A rectifying unit that converts the power supplied from the power generation element from alternating current to direct current; and
A power storage unit that stores power from the rectifying unit;
A booster that boosts the stored electric power;
A wireless transmission unit that performs a wireless transmission operation using power supplied from the booster; and
A timer for driving the boosting unit at a predetermined time interval,
The wireless transmission device is configured to supply a higher one of the voltage of the power storage unit and the output voltage of the boosting unit to the timer.

(2) further comprising: a first diode connected to the power storage unit; and a second diode connected to the output terminal of the boosting unit;
The wireless transmission device according to (1), wherein the timer is connected to a junction between an output terminal of the first diode and an output terminal of the second diode.

  (3) The wireless transmission device according to (1) or (2), wherein the timer is connected to the wireless transmission unit so as to be capable of serial communication.

  (4) The wireless transmission device according to (3), wherein the wireless transmission unit executes serial communication with the timer in order to reset a time count of the timer before performing wireless transmission.

  (5) The wireless transmission device according to (3) or (4), wherein a driving voltage of the boosting unit is set lower than a voltage necessary for driving the timer so as to enable serial communication.

(6) a power generation element that generates power using mechanical energy input from the outside;
A wireless transmission system comprising: the wireless transmission device according to any one of (1) to (5) above.

  According to the present invention, since the output voltage of the booster can be supplied to the timer, the drive voltage of the booster can be set low. Therefore, the wireless transmission device and the wireless transmission system of the present invention can be driven even when the mechanical energy input to the power generation element is weak.

It is a block diagram which shows the conventional radio | wireless transmitter using an energy harvesting element. 1 is a block diagram illustrating a wireless transmission device and a wireless transmission system according to the present invention. FIG. 3 is a cross-sectional perspective view of the power generation element shown in FIG. 2. FIG. 3 is an exploded perspective view of the power generation element shown in FIG. 2. It is a top view of the leaf | plate spring with which the electric power generating element shown in FIG. 2 is provided. FIG. 3 is a block diagram of a wireless transmission unit shown in FIG. 2. It is a flowchart which shows the radio | wireless transmission operation | movement which the radio | wireless transmission part shown in FIG. 2 performs. It is a figure which shows notionally the relationship between the radio | wireless transmission operation | movement shown in FIG. 7, and ON / OFF control of a pressure | voltage rise part and a switching part. It is a figure for demonstrating the improvement effect of the energy efficiency by the radio | wireless transmitter shown in FIG. 1, and a radio | wireless transmission system.

  Hereinafter, a wireless transmission device and a wireless transmission system of the present invention will be described based on preferred embodiments shown in the accompanying drawings. In the following description, the wireless transmission device and the wireless transmission system according to the present invention use a power generation element that generates power using vibration energy input from the outside, but the present invention is not limited to this. Various energy harvesting elements that generate power using various mechanical energy such as pressure may be used in the wireless transmission device and the wireless transmission system of the present invention.

  FIG. 2 is a block diagram showing a wireless transmission device and a wireless transmission system according to the present invention. 3 is a cross-sectional perspective view of the power generating element shown in FIG. FIG. 4 is an exploded perspective view of the power generating element shown in FIG. FIG. 5 is a plan view of a leaf spring included in the power generation element shown in FIG. FIG. 6 is a block diagram of the wireless transmission unit shown in FIG. FIG. 7 is a flowchart showing a wireless transmission operation executed by the wireless transmission unit shown in FIG. FIG. 8 is a diagram conceptually showing the relationship between the wireless transmission operation shown in FIG. 7 and the ON / OFF control of the boosting unit and the switching unit. FIG. 9 is a diagram for explaining an effect of improving energy efficiency by the wireless transmission device and the wireless transmission system shown in FIG. In the following description, the upper side in FIGS. 3 and 4 is referred to as “upper” or “upper”, and the lower side is referred to as “lower” or “lower”.

  A wireless transmission system 900 illustrated in FIG. 2 wirelessly uses a power generation element (environmental power generation element) 100 that generates power using vibration (vibration energy) input from the outside and power supplied from the power generation element 100. And a wireless transmission device 1 that performs transmission.

<Power generation element 100>
The power generating element 100 is fixed to the vibrating body and has a function of generating power using vibration input from the vibrating body. Here, as the vibrating body, for example, rotating equipment (motors, turbines, fans, etc.), air conditioning ducts, piping, transport equipment (freight trains, automobiles, truck beds, etc.), sleepers constituting the railway track, highways, tunnels , Bridges, pumps, pipes for transmitting hydraulic pressure and air pressure, and the like.

  Such a power generating element 100 can be regarded as equivalent to a circuit in which an AC power source E and an internal resistance IR are connected in series as shown in FIG. However, since the power generation element 100 generates power using the vibration input from the vibrating body, the electromotive force of the AC power source E varies depending on the vibration (amplitude, frequency) input from the vibrating body.

  As shown in FIGS. 3 and 4, the power generation element 100 includes a housing 20 and a power generation unit 10 that is held in the housing 20 so as to vibrate in the vertical direction of FIGS. 3 and 4. The power generation unit 10 is provided so as to surround a pair of opposed upper leaf springs 60U and lower leaf springs 60L, a magnet assembly 30 having a permanent magnet 31 fixed therebetween, and an outer peripheral side of the permanent magnet 31. And a coil holding part 50 for holding the coil 40.

  The housing 20 has functions of fixing the power generation element 100 to the vibrating body and accommodating the power generation unit 10. The housing 20 includes a cover 21, a base 23, and a cylindrical portion 22 positioned between the cover 21 and the base 23.

  Through holes 231 are formed in the four corners of the base 23, respectively. By screwing a screw (not shown) through the through hole 231 of the base 23 and screwing it into a screw hole provided in the vibrating body, the base 23 is fixed to the vibrating body, and the power generating element 100 is attached (fixed) to the vibrating body. be able to. By attaching the power generation element 100 to the vibration body, the vibration of the vibration body can be transmitted to the power generation element 100.

  The upper leaf spring 60U and the lower leaf spring 60L have a function of holding the magnet assembly 30 and the coil holding portion 50 with respect to the housing 20 so as to vibrate. The upper leaf spring 60 </ b> U is fixed between the cover 21 and the cylindrical portion 22. On the other hand, the lower leaf spring 60 </ b> L is fixed between the base 23 and the cylindrical portion 22. Each leaf spring is an annular member formed of a metal thin plate material, and has the same structure.

  As shown in FIG. 5, each leaf spring includes a first annular portion 61, a second annular portion 62 having an outer diameter smaller than the inner diameter of the first annular portion 61, and the second from the outer peripheral side, respectively. The third annular portion 63 has an outer diameter smaller than the inner diameter of the annular portion 62. The first annular portion 61, the second annular portion 62, and the third annular portion 63 are each provided concentrically with each leaf spring. The first annular portion 61 and the second annular portion 62 are connected by a plurality of (four in this embodiment) first spring portions 64, and the second annular portion 62 and the third annular portion 62 are connected to each other. The annular portion 63 is connected by a plurality (two in this embodiment) of second spring portions 65.

  In a state where the upper leaf spring 60U is located between the washer 80 provided on the upper side of the upper leaf spring 60U and the coil holding portion 50, the second annular portion 62 of the upper leaf spring 60U is connected to the coil holding portion 50. It is being fixed to the upper end part of an outer peripheral part (tubular part 51). Further, in a state where the lower leaf spring 60L is positioned between the washer 80 provided on the lower side of the lower leaf spring 60L and the coil holding portion 50, the second annular portion 62 of the lower leaf spring 60L is held by the coil. It is fixed to the lower end of the outer peripheral part (tubular part 51) of the part 50.

  Further, the third annular portion 63 of the upper leaf spring 60U is fixed to an upper portion of a spacer 70 attached on the magnet assembly 30 described later, and the third annular portion 63 of the lower leaf spring 60L is a magnet. It is fixed to the bottom of the assembly 30.

  The four first spring portions 64 of each leaf spring support (connect) the second annular portion 62 so as to vibrate in the vertical direction of FIGS. 3 and 4 with respect to the first annular portion 61. As described above, the first annular portion 61 is fixed to the housing 20 (the cover 21, the cylindrical portion 22, and the base 23), and the second annular portion 62 is fixed to the coil holding portion 50. Therefore, when vibration is transmitted from the vibrating body to the housing 20, the vibration is further transmitted to the coil holding unit 50 via the first spring portion 64. As a result, the coil holding unit 50 vibrates with respect to the housing 20.

  Further, the two second spring portions 65 of each leaf spring support (connect) the third annular portion 63 so as to vibrate in the vertical direction of FIGS. 3 and 4 with respect to the second annular portion 62. Yes. As described above, the third annular portion 63 of the upper leaf spring 60U is fixed to the magnet assembly 30 via the spacer 70, and the third annular portion 63 of the lower leaf spring 60L is the magnet assembly. 30 is fixed to the bottom. Therefore, when vibration is transmitted from the vibrating body to the housing 20, vibration is further transmitted to the magnet assembly 30 via the second spring portion 65. As a result, the magnet assembly 30 vibrates with respect to the housing 20 and the coil holding unit 50.

  In the power generating element 100 having such a configuration, the first vibration system in which the coil holding part 50 vibrates by the first spring part 64 of each leaf spring with respect to the case 20, and the case 20 and the coil holding part 50. On the other hand, a second vibration system in which the magnet assembly 30 vibrates is formed by the second spring portion 65 of each leaf spring.

  The magnet assembly 30 is supported between the upper leaf spring 60U and the lower leaf spring 60L so as to vibrate with respect to the housing 20 and the coil holding portion 50. The magnet assembly 30 includes a disk-shaped (relatively thin columnar) permanent magnet 31, a bottom plate portion 321 in which the permanent magnet 31 is disposed substantially at the center, and an outer peripheral end portion of the bottom plate portion 321. A cylindrical back yoke 32 having a cylindrical portion 322 provided and a yoke 33 provided on the upper surface of the permanent magnet 31 are provided. The outer peripheral portion of the bottom plate portion 321 of the back yoke 32 is fixed to the third annular portion 63 of the lower leaf spring 60L, and the yoke 33 is connected to the third annular portion 63 of the upper leaf spring 60U via the spacer 70. It is fixed.

  The back yoke 32 is arranged between the tubular portion 322 and the permanent magnet 31 (yoke 33) in a state where the coil 40 held by the coil holding portion 50 is separated from the tubular portion 322 and the permanent magnet 31. It is configured. That is, the inner diameter of the cylindrical portion 322 is designed to be larger than the outer diameter of the coil 40. A through hole is formed in the bottom plate portion 321 of the back yoke 32 in the vicinity of the center portion.

  The coil holding unit 50 is supported between the magnet assembly 30 and the housing 20 so as to be able to vibrate with respect to the housing 20 and the magnet assembly 30. The coil holding part 50 has a cylindrical tubular part 51 and an annular annular part 52 disposed on the inner peripheral surface side of the tubular part 51. The cylindrical portion 51 is fixed to the second annular portion 62 of each leaf spring. Further, the coil holding part 50 holds the coil 40 on the lower surface side of the annular part 52.

  The coil 40 is fixed to the vicinity of the inner peripheral portion of the lower surface of the annular portion 52 of the coil holding portion 50 and is held by the coil holding portion 50. In addition, the coil 40 is held by the coil holding portion 50 and is separated from the cylindrical portion 322 and the permanent magnet 31 between the cylindrical portion 322 of the back yoke 32 of the magnet assembly 30 and the permanent magnet 31. Are arranged. The coil 40 is displaced in the vertical direction relative to the permanent magnet 31 with the vibration of the power generation unit 10 (vibration of the coil holding unit 50 and vibration of the magnet assembly 30). Due to such vibration, the density of the lines of magnetic force from the permanent magnet 31 passing through the coil 40 changes, and an alternating current is generated in the coil 40.

  Both ends of the coil 40 are connected to a pair of electrode terminals 90 provided on the upper side of the annular part 52 of the coil holding part 50. By connecting the electrode terminal 90 to the input terminal of the wireless transmission device 1, the wireless transmission device 1 can use the power generating element 100 as a power source.

<Wireless transmitter 1>
The wireless transmission device 1 has a function of wirelessly transmitting measurement data acquired by the sensor 8 to an external device such as a host computer, a server, or a control device using the power supplied from the power generation element 100.

  The type of sensor 8 that acquires measurement data to be wirelessly transmitted is not particularly limited, and a sensor that can measure various objects such as temperature, humidity, light, electricity, magnetism, vibration, acceleration, and pressure is referred to as sensor 8. Can be used. In this embodiment, a case where a temperature / humidity sensor capable of measuring temperature and humidity is used as the sensor 8 will be described. In the present embodiment, as shown in FIG. 2, the sensor 8 is described as a component of the wireless transmission device 1, but the present invention is not limited to this. For example, the sensor 8 may be provided outside the wireless transmission device 1 as an independent component, perform data communication with the wireless transmission device 1 by wired connection or wireless connection, and transmit measurement data to the wireless transmission device 1. .

  In the illustrated form, the wireless transmission device 1 has one sensor 8, but the present invention is not limited to this. The wireless transmission device 1 may include a plurality of sensors 8, and the objects measured by the sensors 8 may be different from each other. For example, one of the plurality of sensors 8 may measure temperature and humidity, and a different one of the plurality of sensors 8 may measure vibration.

  As illustrated in FIG. 2, the wireless transmission device 1 includes a rectifying unit 2 that converts power supplied from the power generation element 100 from alternating current to direct current, a power storage unit C1 that stores power from the rectifying unit 2, and a power storage unit C1. Using the boosting unit 3 that boosts the electric power stored therein, the smoothing capacitor C2 that smoothes the output of the boosting unit 3, the sensor 8 that measures temperature and humidity, and the power supplied from the boosting unit 3 Controls the connection between the wireless transmission unit 9 that performs the wireless transmission operation of the measurement data acquired by the sensor 8 (process S100, see FIG. 7), and the smoothing capacitor C2 and the subsequent component (particularly, the wireless transmission unit 9). A switching unit S that controls the boosting unit 3 and the switching unit S in synchronization with the wireless transmission operation of the wireless transmission unit 9, and a first resistor R1 for adjusting the output voltage of the boosting unit 3 And second Including anti-R2, of the output voltage V2 of the boosting unit 3 and the voltage V1 of the power storage unit C1, a first diode D1 and second diode D2 for supplying one higher to the power control unit 4, a.

  Further, in the wireless transmission device 1, at least between the sensor 8 and the wireless transmission unit 9, between the wireless transmission unit 9 and the power control unit 4, between the power control unit 4 and the boosting unit 3, and a power control unit 4 and the switching unit S are communicably connected by a data bus or the like. In particular, the wireless transmission unit 9 and the power control unit 4 are connected such that serial communication, more specifically, I2C (Inter-Integrated Circuit) communication, can be performed. In FIG. 2, components connected so as to be able to perform data communication are connected by an arrow line.

  In the wireless transmission device 1 of the present invention, the power control unit 4 that performs ON / OFF control of the booster 3 and the switching unit S includes a timer 6 for turning on the booster 3 and the switching unit S at a predetermined time interval ΔT. including. The timer 6 is connected to a junction point between the output terminal of the first diode D1 connected to the power storage unit C1 in the previous stage of the booster unit 3 and the output terminal of the second diode D2 connected to the output terminal VOUT of the booster unit 3. Has been. Therefore, the voltage V1R supplied to the timer 6 is the higher one of the voltage V1 of the power storage unit C1 and the output voltage V2 of the boosting unit 3.

<< Rectification unit 2 >>
The rectification unit 2 is connected to the electrode terminal 90 of the power generation element 100 and has a function of converting electric power supplied from the power generation element 100 from alternating current to direct current. The rectifying unit 2 is not particularly limited as long as the power supplied from the power generation element 100 can be converted from alternating current to direct current. For example, a diode rectifier, a bridge rectifier, or the like can be used as the rectifying unit 2.

<< Power storage unit C1 >>
The power storage unit C1 has a function of storing and discharging (charging / discharging) the electric power from the rectifying unit 2. One terminal of the power storage unit C1 is connected to the output terminal of the rectifying unit 2, and the other terminal is connected to the ground (reference potential point). As illustrated, the voltage of the power storage unit C1 is expressed by the voltage V1.

  As the power storage unit C1, for example, a capacitor such as an electric double layer capacitor or a lithium ion capacitor can be used. Such a capacitor is suitable as the power storage unit C1 because it can be rapidly charged and is small. Moreover, you may use the combination of a capacitor | condenser and secondary batteries (storage battery), such as a lead battery, a lithium ion battery, and a nickel metal hydride battery, as the electrical storage part C1. In this case, when power exceeding the capacity of the capacitor is supplied, surplus power can be stored in the secondary battery, so that the power supplied from the power generation element 100 is used more efficiently. be able to.

<< Pressure Booster 3 >>
The boosting unit 3 is connected in parallel with the power storage unit C1, and has a function of boosting and outputting the power stored in the power storage unit C1. Booster unit 3 is not particularly limited as long as it can boost and output the electric power stored in power storage unit C1, and typically a DC-DC converter can be used as booster unit 3.

  The output terminal VOUT of the booster 3 is connected to one terminal of the smoothing capacitor C2. The FB terminal (output voltage feedback terminal) of the booster 3 is connected between a first resistor R1 and a second resistor R2 connected in parallel to the smoothing capacitor C2. With such a configuration, the output voltage of the booster 3 output from the output terminal VOUT can be adjusted by adjusting the resistance values of the first resistor R1 and the second resistor R2. For example, when a voltage of 0.9 V is input to the booster 3 of the present embodiment, an output voltage of 2.2 V can be output from the output terminal VOUT. Further, the output terminal of the power control unit 4 is connected to the gate terminal of the boosting unit 3, and ON / OFF control of the boosting unit 3 is executed according to a control signal output from the power control unit 4. As shown in the figure, the output voltage of the booster 3 is expressed by a voltage V2.

<< Smoothing capacitor C2 >>
The smoothing capacitor C2 has a function of smoothing the output of the boosting unit 3 output from the output terminal VOUT and supplying it to the subsequent components (first resistor R1, second resistor R2, sensor 8 and wireless transmission unit 9). Have. One terminal of the smoothing capacitor C2 is connected to the output terminal VOUT of the boosting unit 3, and the other terminal is connected to the ground. As the smoothing capacitor C2, a capacitor similar to the above-described power storage unit C1 can be used.

<< Switching part S >>
The switching unit S is connected in parallel with the smoothing capacitor C2 and has a function of controlling connection between the smoothing capacitor C2 and a subsequent component in accordance with a control signal output from the power control unit 4. The switching unit S includes a first semiconductor switching element Q1, a second semiconductor switching element Q2, and a third resistor R3.

  One terminal of the source terminal or the drain terminal of the first semiconductor switching element Q1 is connected to one terminal of the smoothing capacitor C2, and the other terminal is connected to a subsequent component. The gate terminal of the first semiconductor switching element Q1 is connected to one of the source terminal and the drain terminal of the second semiconductor switching element Q2. The other terminal of the second semiconductor switching element Q2 is grounded. The gate terminal of the second semiconductor switching element Q2 is connected to the output terminal of the power control unit 4, and a control signal output from the power control unit 4 to the boosting unit 3 is transmitted to the second semiconductor switching element Q2. Is also output to the gate terminal. The third resistor R3 is connected between one terminal of the smoothing capacitor C2 and the gate terminal of the first semiconductor switching element Q1, and adjusts the voltage input to the gate terminal of the first semiconductor switching element Q1. Used to do.

  The first semiconductor switching element Q1 and the second semiconductor switching element Q2 are normally open (NO) type switching elements. For example, a MOSFET, an IGBT, or the like is used as the first semiconductor switching element Q1 or the second semiconductor switching element. It can be used as the element Q2.

  When the control signal is output from the power control unit 4 to the gate terminal of the second semiconductor switching element Q2, the second semiconductor switching element Q2 is turned ON. As a result, a current flows through the gate terminal of the first semiconductor switching element Q1, and the first semiconductor switching element Q1 is turned on. As a result, the switching unit S is turned on, and the power smoothed by the smoothing capacitor C2 is supplied to the subsequent component via the switching unit S. Further, since the control signal output to the gate terminal of the second semiconductor switching element Q2 is the same control signal as the control signal output to the gate terminal of the booster 3, the booster 3 is simultaneously turned on.

  By using the switching unit S having such a configuration, the connection between the smoothing capacitor C2 and the subsequent component can be controlled in synchronization with the ON / OFF control of the boosting unit 3. Furthermore, as described above, the control signal output to the gate terminal of the booster 3 and the gate terminal of the second semiconductor switching element Q2 is synchronized with the wireless transmission operation of the wireless transmitter 9. Therefore, during the standby state in which the wireless transmission unit 9 does not perform the wireless transmission operation, the connection between the smoothing capacitor C2 and the subsequent component can be reliably disconnected. As a result, the power in the smoothing capacitor C2 is unnecessary due to factors other than the wireless transmission operation of the wireless transmission unit 9, that is, standby power of the first resistor R1, the second resistor R2, the sensor 8, and the wireless transmission unit 9. It is possible to prevent consumption. As a result, since the inrush current from the boosting unit 3 to the smoothing capacitor C2 is reduced, it is possible to prevent the power stored in the power storage unit C1 from being consumed unnecessarily, and to improve the energy efficiency of the wireless transmission device 1. Can be improved.

<< Diodes D1, D2 >>
Between one terminal of the smoothing capacitor C2 and the switching unit S, an input terminal (anode) of the second diode D2 is connected. On the other hand, the input terminal of the first diode D1 is connected to one terminal of the power storage unit C1. The output terminal (cathode) of the first diode D1 is connected to the output terminal of the second diode D2. Therefore, the voltage V1R output from the junction of the output terminal of the first diode D1 and the output terminal of the second diode D2 is one of the higher one of the voltage V1 of the power storage unit C1 and the output voltage V2 of the booster unit 3. It is.

  As described above, the first diode D1 and the second diode D2 are configured such that the higher one of the voltage V1 of the power storage unit C1 and the output voltage V2 of the boosting unit 3 is higher than the output terminal of the first diode D1. It is used to output from the junction point of the output terminal of the diode D2.

  For example, when the voltage V1 of the power storage unit C1 is higher than the output voltage V2 of the boosting unit 3, the voltage V1R output from the junction of the output terminal of the first diode D1 and the output terminal of the second diode D2 is This is the voltage V1 of the part C1. On the other hand, when the output voltage V2 of the boosting unit 3 is higher than the voltage V1 of the power storage unit C1, the voltage V1R output from the junction of the output terminal of the first diode D1 and the output terminal of the second diode D2 is boosted. This is the output voltage V <b> 2 of the unit 3. The junction point between the output terminal of the first diode D1 and the output terminal of the second diode D2 is connected to the power control unit 4.

<< Power control unit 4 >>
The power control unit 4 is connected between the power storage unit C1 and the booster unit 3 and is turned on / off of the booster unit 3 and the switching unit S in synchronization with the wireless transmission operation (process S100) executed by the wireless transmission unit 9. It has a function to execute control. As shown in the figure, the power control unit 4 is connected to the junction of the power monitoring circuit 5 connected in parallel with the power storage unit C1 and the output terminal of the first diode D1 and the output terminal of the second diode D2. A timer 6 and an adder 7 connected to the output terminal of the power supply monitoring circuit 5 and the output terminal of the timer 6 are provided.

  The power supply monitoring circuit 5 is connected in parallel with the power storage unit C1, and has a function of monitoring the voltage V1 of the power storage unit C1 and outputting a signal to the adder 7 according to the monitoring result. When the power supply monitoring circuit 5 detects that the voltage V1 has become equal to or higher than a predetermined upper threshold value, it outputs a signal to the adder 7 (the output becomes a logical value High). Thereafter, the voltage V1 of the power storage unit C1 drops due to a wireless transmission operation or the like performed by the wireless transmission unit 9. When the power supply monitoring circuit 5 detects that the voltage V1 has become less than the predetermined lower threshold value due to the voltage drop, the power supply monitoring circuit 5 stops outputting the signal to the adder 7 (the output becomes the logic value Low).

  The lower threshold value for voltage V1 is set to be the minimum operable voltage of booster 3. On the other hand, when the minimum operable voltage of the booster unit 3 is Vmin, and the drop amount of the voltage V1 when the wireless transmission unit 9 executes one wireless transmission operation is ΔV, the upper threshold value for the voltage V1 is , Vmin + ΔV or more is preferable. For example, when the minimum operable voltage Vmin of the booster 3 is 0.9 V and the drop amount ΔV of the voltage V1 when the wireless transmission unit 9 executes one wireless transmission operation is 0.2 V, the voltage V1 The lower threshold for the voltage V is 0.9V, and the upper threshold for the voltage V1 is set to 1.1V or higher.

  Thus, by setting the upper threshold value for voltage V1 to Vmin + ΔV or more, voltage V1 of power storage unit C1 is the minimum operable voltage Vmin of boosting unit 3 while wireless transmission unit 9 is performing the wireless transmission operation. It is possible to reliably prevent the wireless transmission operation from being interrupted. Further, by setting the lower threshold value for voltage V1 to the minimum operable voltage Vmin of boosting unit 3, even though voltage V1 of power storage unit C1 is less than minimum operable voltage Vmin of boosting unit 3. Thus, it is possible to prevent power from being supplied from the power storage unit C1 to the booster unit 3 and unnecessary consumption of power.

  The timer 6 is connected to the junction point of the output terminal of the first diode D1 and the output terminal of the second diode D2, and outputs a signal to the adder 7 at every predetermined time interval ΔT (to the adder 7). The output is changed from the logic value Low to the logic value High), and the boosting unit 3 and the switching unit S are turned on (driven). In addition, as described above, the timer 6 is connected to the wireless transmission unit 9 so that I2C communication is possible.

  In the initial state, the timer 6 continues to output a signal to the adder 7 (the output is a logical value High). Thereafter, the timer 6 sends a time interval setting signal for setting a predetermined time interval ΔT and a timer count reset signal for resetting the time count of the timer 6 from the wireless transmission unit 9 to the I2C before the wireless transmission is executed. Receive by communication.

  The timer 6 continues to output signals to the adder 7 until it receives a timer output OFF signal from the wireless transmission unit 9 even after receiving the time interval setting signal and the timer count reset signal from the wireless transmission unit 9 (logical value). High output is maintained). The timer 6 receives the timer output OFF signal from the wireless transmission unit 9 and stops outputting the signal to the adder 7 (after the logical value is Low), and then the predetermined value set by the wireless transmission unit 9 When the time interval ΔT is counted, the output of the signal to the adder 7 is restarted (the output is changed from the logic value Low to the logic value High).

  As described above, the timer 6 stops outputting the signal to the adder 7 in accordance with the timer output OFF signal from the wireless transmission unit 9, and outputs the signal to the adder 7 when the predetermined time interval ΔT is counted. Configured to resume. Further, the timer output OFF signal and the timer count reset signal described above are periodically transmitted from the wireless transmission unit 9 to the timer 6, so that the timer 6 periodically outputs and stops the signal to the adder 7. Can be repeated.

  As will be described later with reference to FIGS. 7 and 8, the transmission of the time interval setting signal and the time count reset signal by the wireless transmission unit 9 is performed before the wireless transmission is performed. On the other hand, the transmission of the timer output OFF signal by the wireless transmission unit 9 is executed after the wireless transmission is executed. Therefore, after the wireless transmission unit 9 starts the wireless transmission operation (process S100), the timer 6 is in a state in which I2C communication is always possible in order to receive a signal from the wireless transmission unit 9 before and after performing wireless transmission. Need to be driven by.

  As described above, the timer 6 needs to receive the above-described various signals output from the wireless transmission unit 9 by I2C communication after the wireless transmission unit 9 starts the wireless transmission operation. Therefore, after the wireless transmission unit 9 starts the wireless transmission operation, it is necessary to constantly supply the timer 6 with a voltage necessary for driving the timer 6 so that I2C communication is possible (hereinafter referred to as I2C communication possible voltage). . Generally, the I2C communicable voltage is higher than the minimum operable voltage Vmin of the booster 3. For example, the I2C communicable voltage is at least 1.5 V, and is higher than the minimum operable voltage Vmin (0.9 V in the above example) of the booster 3.

  Therefore, when power is supplied from only the power storage unit C1 to the timer 6, the voltage V1 of the power storage unit C1 needs to be constantly maintained at or above the I2C communication executable voltage (1.5 V in the above example). Therefore, conventionally, in order to prevent the voltage V1 of the power storage unit C1 from dropping below the I2C communication executable voltage, it is necessary to set the drive voltage of the booster unit 3 to be equal to or higher than the I2C communication executable voltage. However, if the drive voltage of the booster 3 is set high, if the vibration (mechanical energy) input to the power generation element 100 is weak, the booster 3 may not be driven and the wireless transmission device 1 may not be driven. .

  On the other hand, the timer 6 of the present embodiment receives electric power supplied from the junction point of the output terminal of the first diode D1 and the output terminal of the second diode D2. Therefore, the voltage V1R of the power supplied to the timer 6 is one of the higher one of the voltage V1 of the power storage unit C1 and the output voltage V2 of the boosting unit 3.

  Therefore, before the boosted power is output from the boosting unit 3, that is, before the voltage V1 of the power storage unit C1 is lower than the drive voltage of the boosting unit 3 and the wireless transmission unit 9 starts the wireless transmission operation, the timer 6 The voltage V1R supplied to is the voltage V1 of the power storage unit C1.

  On the other hand, after the boosted power is output from the boosting unit 3 and the wireless transmission unit 9 starts the wireless transmission operation, that is, while the output voltage V2 of the boosting unit 3 is higher than the voltage V1 of the power storage unit C1, the timer The voltage V1R supplied to 6 becomes the output voltage V2 of the booster 3.

  In this way, by connecting the timer 6 to the junction of the output terminal of the first diode D1 and the output terminal of the second diode D2, before the wireless transmission unit 9 starts the wireless transmission operation, that is, the timer While it is not necessary to supply the I2C communicable voltage to 6, the voltage V1 of the power storage unit C1 can be supplied to the timer 6. On the other hand, after the wireless transmission unit 9 starts the wireless transmission operation, that is, while it is necessary to supply the I2C communicable voltage to the timer 6, the output voltage V2 of the boosting unit 3 can be supplied to the timer 6. .

  Therefore, in the wireless transmission device 1 of the present invention, it is not necessary to keep the voltage V1 of the power storage unit C1 at or above the I2C communicable voltage. For this reason, the drive voltage of the booster 3 can be set to a minimum level that is the minimum operable voltage Vmin (or the upper threshold value) of the booster 3. As a result, even if the vibration (mechanical energy) input to the power generation element 100 is weak, the booster 3 can be driven and the wireless transmission device 1 can be driven.

  The adder 7 is connected to the output terminal of the power supply monitoring circuit 5 and the output terminal of the timer 6, and only when a signal (High output) is received from both the power supply monitoring circuit 5 and the timer 6, the gate terminal of the booster 3. And a function of outputting a control signal to the gate terminal of the second semiconductor switching element Q2.

  As described above, in the initial state, the timer 6 continues to output a signal to the adder 7. Therefore, before the first wireless transmission operation is performed by the wireless transmission unit 9, when the voltage V <b> 1 of the power storage unit C <b> 1 is equal to or higher than a predetermined upper threshold value, the adder 7 to the gate of the boosting unit 3. A control signal is output to the terminal and the gate terminal of the second semiconductor switching element Q2.

  On the other hand, after the timer 6 receives the timer output OFF signal and stops outputting the signal to the adder 7, the voltage V1 of the power storage unit C1 is equal to or higher than a predetermined lower threshold value, and the timer 6 When the predetermined time interval ΔT is counted and the output of the signal to the adder 7 is resumed, a control signal is output from the adder 7 to the gate terminal of the booster 3 and the gate terminal of the second semiconductor switching element Q2. The By using the power control unit 4 having such a configuration, the boosting unit 3 and the switching unit S can be turned on at a predetermined time interval ΔT.

<< Resistance R1, R2 >>
The first resistor R1 and the second resistor R2 are connected in parallel with the smoothing capacitor C2 after the switching unit S. One terminal of the first resistor R1 is connected to the other terminal of the first semiconductor switching element Q1, and the other terminal is connected to one terminal of the second resistor R2. The other terminal of the second resistor R2 is grounded, and the FB terminal of the booster 3 is connected between the other terminal of the first resistor R1 and one terminal of the second resistor. Yes. Therefore, the first resistor R1 and the second resistor R2 constitute a voltage dividing circuit, and the resistance values of the first resistor R1 and the second resistor R2 are adjusted, whereby the voltage to the FB terminal of the boosting unit 3 is adjusted. The feedback voltage can be adjusted. For example, when the resistance values of the first resistor R1 and the second resistor R2 are equal, the feedback voltage to the FB terminal of the booster 3 is approximately half of the output voltage V2 of the booster 3.

<< Sensor 8 >>
The sensor 8 is connected in parallel with the smoothing capacitor C2 after the switching unit S, and has a function of measuring temperature and humidity and outputting measurement data to the wireless transmission unit 9.

  When the booster 3 and the switching unit S are turned on and electric power is supplied from the booster 3, the sensor 8 is turned on and starts measuring temperature and humidity. The sensor 8 has a measurement standby time from when power is supplied from the booster 3 to when it becomes possible to measure at least one of temperature and humidity. For example, in this embodiment, the measurement standby time until the sensor 8 is in a state where at least one of temperature and humidity can be measured is 15 msec.

  After a predetermined measurement standby time has elapsed, the sensor 8 starts measuring at least one of temperature and humidity, and transmits the acquired measurement data to the wireless transmission unit 9. If the sensor 8 is configured to be able to measure both temperature and humidity at the same time, the sensor 8 measures both temperature and humidity at the same time, and transmits temperature and humidity measurement data to the wireless transmission unit 9. May be.

  When the wireless transmission unit 9 performs wireless transmission of measurement data and resets the time count of the timer 6, the boosting unit 3 and the switching unit S are turned off, and the power supply to the sensor 8 is stopped. When the power supply to the sensor 8 is stopped, the power source of the sensor 8 is turned off.

<< Wireless Transmission Unit 9 >>
The wireless transmission unit 9 is connected in parallel with the smoothing capacitor C2 after the switching unit S, and has a function of wirelessly transmitting measurement data related to temperature and humidity measured by the sensor 8 to an external device such as a host computer or a server.

  As shown in FIG. 6, the wireless transmission unit 9 includes a control unit 91, an on-chip regulator 92 that controls power supply to the control unit 91, and a module 93 for executing various functions of the wireless transmission unit 9. I have.

  The control unit 91 has a function of controlling the operation of the wireless transmission unit 9. The control unit 91 includes at least one processor 911 and a memory 912. At least one processor 911 is any device that fetches and executes computer-readable instructions stored in memory 912. For example, a microprocessor, a microcomputer, a microcontroller, a digital signal processor, a central processing unit (CPU), a state machine, a logic circuit, or the like can be used as the processor 911.

  The memory 912 includes a non-volatile memory 913 such as a ROM that stores computer-readable instructions read by the control unit 91, and a volatile memory 914 such as a RAM that temporarily stores instructions and data. The volatile memory 914 can store instructions and data while power is supplied to the control unit 91. On the other hand, when the power supply to the control unit 91 is stopped, the commands and data temporarily stored in the volatile memory 914 are deleted.

  The on-chip regulator (internal power supply circuit) 92 has a function of controlling power supply to the control unit 91 according to the content of processing to be executed by the wireless transmission unit 9. By using the on-chip regulator 92, fluctuations in the power supply voltage of the wireless transmission unit 9 can be suppressed. Furthermore, when it is not necessary to use the control unit 91, the power supply to the control unit 91 can be stopped, so that the power consumption of the wireless transmission unit 9 can be reduced.

  In the wireless transmission unit 9, power is supplied to the control unit 91, and an active mode in which the processor 911 in the control unit 91 outputs a main clock and an inactive mode in which the processor 911 in the control unit 91 stops outputting the main clock. It is possible to operate. In the non-active mode, power is supplied to the control unit 91 and the processor 911 of the control unit 91 stops the output of the main clock, and power is not supplied to the control unit 91, and the processor of the control unit 91 911 includes a power down mode in which the output of the main clock is stopped.

  In the active mode, since the processor 911 outputs the main clock, the power consumption is relatively large, but all the functions of the wireless transmission unit 9 can be executed. Therefore, the active mode is also called a full function mode. On the other hand, in the non-active mode, since the processor 911 stops outputting the main clock, the power consumption is relatively small, but the number of functions that can be executed is limited.

  Further, in the power saving mode of the non-active mode, since power is supplied to the control unit 91 by the on-chip regulator 92, the volatile memory 914 can continue to hold commands and data. On the other hand, in the power-off mode of the non-active mode, since the power supply to the control unit 91 is stopped by the on-chip regulator 92, the command and data temporarily stored in the volatile memory 914 are erased. Power consumption is minimized.

  That is, when the above three modes are arranged in order of power consumption, the active mode> the power saving mode> the power off mode is established. For example, the power consumption per second of the wireless transmission unit 9 in the active mode in the present embodiment is 14.5 mW, and the power consumption per second of the wireless transmission unit 9 in the power saving mode is 0.4 mW. The power consumption per second of the wireless transmission unit 9 in the power down mode is 0.002 mW. The wireless transmission unit 9 of the present invention reduces the power consumption required for the wireless transmission operation (processing S100) by operating by switching the above three modes according to the processing to be executed by the wireless transmission unit 9. Can do.

  The module 93 is a routine, program, object, or the like for executing various functions, and is stored in a storage unit such as a nonvolatile memory 913 or a database. The module 93 includes a non-active mode module 94 that can be executed in both the non-active mode and the active mode, and an active mode module 95 that can be executed only in the active mode.

  The non-active mode module 94 includes a mode switching module 941 for switching the above three modes and a time count module 942 for counting time.

  The mode switching module 941 is executed to switch the above three modes according to the process to be executed by the wireless transmission unit 9. Therefore, even when operating in the power down mode, the wireless transmission unit 9 can execute the mode switching module 941. As trigger events for the mode switching module 941 to switch modes, for example, the initial setting of the wireless transmission unit 9 is completed, the time counting module 942 counts a predetermined time interval, the measurement of the sensor 8 is started, etc. Event.

  The time count module 942 is a module executed to count time, and the wireless transmission unit 9 always executes the time count module 942 while the power is on. Therefore, even when operating in the power down mode, the wireless transmission unit 9 can perform time counting using the time counting module 942.

  The active mode module 95 includes an interface module 951 for performing data communication with the sensor 8, a sensor control module 952 for controlling the sensor 8, a timer control module 953 for controlling the timer 6, and wireless transmission. A wireless transmission module 954 for execution.

  The interface module 951 is executed to perform data communication with the sensor 8. The wireless transmission unit 9 receives the measurement data from the sensor 8 using the interface module 951 and stores it in the volatile memory 914.

  The sensor control module 952 is executed to control the temperature and humidity measurements performed by the sensor 8. The wireless transmission unit 9 waits for a predetermined measurement standby time, transitions to a state where at least one of temperature and humidity can be measured, and then uses the sensor control module 952 to measure the temperature and humidity of the sensor 8. The measurement start process for starting is executed.

  When the sensor 8 can measure a plurality of measurement objects (that is, temperature and humidity) as in this embodiment, the wireless transmission unit 9 uses the sensor control module 952 to measure the measurement object that the sensor 8 should measure. Can be specified. When the sensor 8 is configured to be able to measure a plurality of measurement objects at the same time, the wireless transmission unit 9 may specify to measure a plurality of measurement objects at the same time.

  In addition, the wireless transmission unit 9 can confirm whether or not the measurement of the measurement target designated by the sensor 8 is completed by using the sensor control module 952. Further, the wireless transmission unit 9 uses the sensor control module 952 to check whether all the measurement objects to be measured by the sensor 8 have been measured. When the sensor 8 has not measured all the measurement targets to be measured, the wireless transmission unit 9 designates the measurement target of the sensor 8 again using the sensor control module 952 and continues the measurement.

  The timer control module 953 is executed to control the timer 6. The wireless transmission unit 9 uses the timer control module 953 to set a time interval setting signal for setting a predetermined time interval ΔT of the timer 6, a time count reset signal for resetting the time count of the timer 6, and the timer 6 A timer output OFF signal for stopping the output can be output to the timer 6.

  Thus, the wireless transmission unit 9 uses the timer control module 953 to set the predetermined time interval ΔT of the timer 6, reset the time count of the timer 6, and further stop the output of the timer 6. The output of the timer 6 can be turned ON / OFF at a desired timing. Note that the predetermined time interval ΔT of the timer 6 set by the wireless transmission unit 9 can be appropriately set according to the amount of measurement data to be wirelessly transmitted by the wireless transmission unit 9, the performance of the sensor 8, the power generation capability of the power generation element 100, and the like. It is. The value of the time interval ΔT is stored in advance in the nonvolatile memory 913 and can be changed by external input to the wireless transmission unit 9.

  The wireless transmission module 954 is executed to wirelessly transmit measurement data (that is, measurement data related to temperature and humidity) measured by the sensor 8 stored in the volatile memory 914 to an external device such as a host computer or a server. Is done.

  The wireless transmission unit 9 may be configured to be able to adjust the amount of data wirelessly transmitted by one wireless transmission. In general, since the power consumed by one wireless transmission is proportional to the amount of data to be transmitted (number of bytes), the wireless transmission unit 9 adjusts the amount of data to be transmitted by one wireless transmission. The power consumed by wireless transmission can be adjusted. The amount of data transmitted by one wireless transmission is appropriately adjusted according to the measurement object to be measured by the sensor 8, the performance of the sensor 8, the time interval ΔT of the timer 6, the power generation capability of the power generation element 100, and the like.

(Processing S100)
Next, the process S100 (wireless transmission operation) executed by the wireless transmission unit 9 will be described with reference to FIGS.

  When the power generation element 100 starts power generation by vibration input from the outside, electric power is supplied from the power generation element 100 to the power storage unit C1 and stored. Thereafter, when the voltage V1 of the power storage unit C1 becomes equal to or higher than a predetermined upper threshold value, a signal is output from the power supply monitoring circuit 5 of the power control unit 4 to the adder 7. In the initial state, since the timer 6 continues to output a signal to the adder 7, when the signal is output from the power monitoring circuit 5 to the adder 7, the adder 7 controls the booster 3 and the switching unit S. A signal is output. As a result, the booster 3 and the switching unit S are turned on, power is supplied from the booster 3 to the smoothing capacitor C2, and the output of the booster 3 is smoothed. Thereafter, when power is supplied from the booster 3 to the wireless transmission unit 9, the power of the wireless transmission unit 9 is turned on, and the process S100 of the wireless transmission unit 9 is started.

  The wireless transmission unit 9 starts the process S100 in the active mode. First, in step S101, the wireless transmission unit 9 performs its own initial setting. In step S101, the wireless transmission unit 9 communicates with the sensor 8 using the interface module 951, acquires various performances such as the measurable target of the sensor 8, the measurement resolution, the measurement waiting time described above, and the like. Initial setting of parameters such as the number, the order of measurement, the measurement standby time, the amount of data to be wirelessly transmitted, and the number of times of wireless transmission to be performed is executed. The various parameters set in step S101 are stored in the nonvolatile memory 913. For this reason, the wireless transmission unit 9 can continue to retain these parameters even after shifting from the active mode (or power saving mode) to the power down mode.

  In addition, the parameter initially set in step S101 is not limited to this, The arbitrary parameter required for various operation | movement which the radio | wireless transmitter 1 performs can be initialized. When the initial setting of the wireless transmission unit 9 is completed, the process S100 proceeds to step S102.

  In step S102, the wireless transmission unit 9 uses the mode switching module 941 to shift from the active mode to the power down mode. Thereafter, in step S103, the wireless transmission unit 9 uses the time count module 942 to measure the measurement standby time of the sensor 8 set in step S101 (for example, in this embodiment, the measurement standby time of the sensor 8 is 15 msec. Wait until the time count for (there is). In this way, by operating the wireless transmission unit 9 in the power-down mode until the sensor 8 becomes measurable, unnecessary power consumption by the wireless transmission unit 9 (particularly, the processor 911 of the control unit 91) is reduced. Can be reduced.

  After the wireless transmission unit 9 counts the measurement standby time using the time count module 942, the process S100 proceeds to step S104. In step S104, the wireless transmission unit 9 uses the mode switching module 941 to shift from the power down mode to the active mode.

  In step S <b> 105, the wireless transmission unit 9 sets the time interval ΔT of the timer 6 and resets the time count of the timer 6 using the timer control module 953. The timer 6 outputs a signal to the adder 7 until the timer output OFF signal is received from the wireless transmission unit 9 in a later step even after the time interval ΔT is set and the time count is reset in step S105. (The output of the logical value High is continued).

  In step S <b> 105, the wireless transmission unit 9 reads the value of the time interval ΔT stored in advance in the nonvolatile memory 913 and sets the time interval ΔT of the timer 6. A plurality of values of the time interval ΔT may be stored in the nonvolatile memory 913. Further, the value of the time interval ΔT that is set every time the wireless transmission unit 9 executes the process S100 may be the same value every time, or may be changed according to the power generation amount of the power generation element 100. For example, when the power monitoring circuit 5 detects that the power generation amount of the power generation element 100 has decreased, a relatively long time interval ΔT is set, and the power generation monitoring circuit 5 indicates that the power generation amount of the power generation element 100 has increased. If detected, a relatively short time interval ΔT can be set.

  In step S <b> 106, the wireless transmission unit 9 uses the sensor control module 952 to execute measurement start processing for starting temperature and humidity measurement by the sensor 8. When the measurement start process is executed by the wireless transmission unit 9, the process S100 proceeds to step S107. In step S <b> 107, the wireless transmission unit 9 uses the sensor control module 952 to specify a measurement target to be measured by the sensor 8, that is, one of temperature and humidity. When the sensor 8 is configured to be able to measure temperature and humidity at the same time, the wireless transmission unit 9 may use the sensor control module 952 to specify that the temperature and humidity be measured simultaneously.

  If at least one of temperature and humidity is specified in step S107, the process S100 proceeds to step S108. In step S108, the wireless transmission unit 9 shifts from the active mode to the power saving mode using the mode switching module 941. In step S108, when the wireless transmission unit 9 starts operating in the power saving mode, the sensor 8 starts measuring at least one of the designated measurement object, that is, temperature or humidity.

  In step S108, when the wireless transmission unit 9 shifts to the power saving mode and the sensor 8 starts measurement of the specified measurement target, the process S100 shifts to step S109. In step S <b> 109, the wireless transmission unit 9 waits for a predetermined time until the measurement of the sensor 8 is completed, using the time count module 942. The predetermined time that the wireless transmission unit 9 waits in step S109 is not particularly limited, and is appropriately set according to various performances such as the measurement resolution of the sensor 8 acquired using the interface module 951 in step S101. For example, in this embodiment, the wireless transmission unit 9 waits for 66 msec for temperature measurement and 22 msec for humidity measurement in step S109.

  In this way, while the sensor 8 performs measurement of the designated measurement target, the wireless transmission unit 9 operates in the power saving mode. As described above, in the power saving mode, since the processor 911 stops outputting the main clock, unnecessary power consumption by the processor 911 can be reduced. On the other hand, in the power saving mode, since power is supplied to the control unit 91 (memory 912), data or instructions necessary for measurement control of the sensor 8 and wireless transmission of measurement data, for example, the type of the specified measurement target, Measurement values (measurement data), the number of measurements, and the like can be stored in the volatile memory 914. Accordingly, unnecessary power consumption by the processor 911 can be reduced while holding necessary data or instructions in the volatile memory 914 while the sensor 8 performs measurement of the designated measurement target. .

  In step S109, after the wireless transmission unit 9 waits for a predetermined time, the process S100 proceeds to step S110. In step S110, the wireless transmission unit 9 uses the mode switching module 941 to shift from the power saving mode to the active mode. Thereafter, the process S100 proceeds to step S111. In step S <b> 111, the wireless transmission unit 9 uses the sensor control module 952 to determine whether or not the measurement of the specified measurement target has been completed. If it is determined in step S111 that the measurement of the designated measurement target has not been completed, the process S100 proceeds to step S112.

  In step S112, the wireless transmission unit 9 shifts from the active mode to the power saving mode using the mode switching module 941. Thereafter, the process S100 proceeds to step S113. In step S113, the wireless transmission unit 9 waits for a predetermined time using the time count module 942. The predetermined time that the wireless transmission unit 9 waits in step S113 is not particularly limited, and is appropriately set according to various performances such as the measurement resolution of the sensor 8 acquired using the interface module 951 in step S101. For example, in the present embodiment, the wireless transmission unit 9 waits for 1 msec in step S113. As described above, in the case where it is determined in step S111 that the measurement of the designated measurement target has not been completed, unnecessary power consumption by the processor 911 is reduced by operating the wireless transmission unit 9 in the power saving mode. Can be reduced.

  In step S113, after the wireless transmission unit 9 waits for a predetermined time, the process S100 proceeds to step S110 again. In step S110, the wireless transmission unit 9 again shifts from the power saving mode to the active mode, and then determines whether the measurement of the measurement target specified in step S111 is completed. In this way, the process S100 repeats steps S110 to S113 until the measurement of the designated measurement object is completed.

  On the other hand, when it is determined in step S111 that the measurement of the designated measurement target has been completed, the process S100 proceeds to step S114. In step S <b> 114, the wireless transmission unit 9 communicates with the sensor 8 using the interface module 951 and reads measurement data from the sensor 8. The acquired measurement data is temporarily stored in the volatile memory 914.

  Thereafter, the process S100 proceeds to step S115. In step S <b> 115, the wireless transmission unit 9 uses the sensor control module 952 to determine whether all of the measurement targets (temperature and humidity in this embodiment) to be measured by the sensor 8 have been measured. If it is determined in step S115 that all measurement objects have not been measured (that is, one of temperature and humidity has not been measured), the process S100 returns to step S107. In step S <b> 107, the wireless transmission unit 9 uses the sensor control module 952 to designate a measurement target that has not been measured as a measurement target to be measured by the sensor 8. The process S100 repeatedly executes the above-described steps S107 to S115 until the measurement of all measurement objects is completed.

  On the other hand, if it is determined in step S115 that all the measurement objects to be measured by the sensor 8 have been measured, the process S100 proceeds to step S116. In step S116, the wireless transmission unit 9 uses the wireless transmission module 954 to read temperature and humidity measurement data stored in the volatile memory 914 and wirelessly transmit the data to an external device such as a host computer or a server. Note that the wirelessly transmitted measurement data may be deleted from the volatile memory 914 in the FIFO format. Accordingly, the volatile memory 914 can be prevented from being saturated, so that a volatile memory having a small capacity can be used as the volatile memory 914.

  Thereafter, the process S100 proceeds to step S117. In step S117, the wireless transmission unit 9 transmits a timer output OFF signal to the timer 6 using the timer control module 953, and stops the output of the signal from the timer 6 to the adder 7 (the output of the timer 6 is logical). Value Low). When the timer 6 stops the output to the adder 7 in step S117, the booster 3 and the switching unit S are turned off, and the power supply to the wireless transmitter 9 is stopped. When power supply from the booster 3 to the wireless transmitter 9 is stopped, the power of the wireless transmitter 9 is turned off, and the process S100 ends. The process S100 is repeatedly executed until a predetermined number of times of wireless transmission is executed.

  Next, with reference to FIG. 8, the relationship between the process S100 (wireless transmission operation) repeatedly executed by the wireless transmission unit 9 and the ON / OFF control of the booster 3 and the switching unit S will be described. 8 includes a timing chart of the timer 6, the power supply monitoring circuit 5, the boosting unit 3, and the switching unit S. For the sake of simplification and explanation, the horizontal axis (time axis) of the timing chart is shown. Is not linear.

  At the timing when electric power is supplied from the power generation element 100 to the wireless transmission device 1, the voltage V1 of the power storage unit C1 is lower than the predetermined upper threshold value, so that no signal is output from the power supply monitoring circuit 5 to the adder 7. That is, the output of the power supply monitoring circuit 5 is the logical value Low. On the other hand, the timer 6 in the initial state continues to output a signal to the adder 7. That is, the output of the timer 6 is the logical value High. Therefore, at the timing when power is supplied from the power generating element 100 to the wireless transmission device 1, the booster 3 and the switching unit S are in the OFF state as illustrated.

  Thereafter, at the timing P1 when the voltage V1 of the power storage unit C1 becomes equal to or higher than a predetermined upper threshold value, the output of the power supply monitoring circuit 5 becomes the logical value High. Thereafter, the output from the power supply monitoring circuit 5 maintains the logical value High until the voltage V1 of the power storage unit C1 becomes less than a predetermined lower threshold value.

  At timing P1, the booster 3 and the switching unit S are turned ON, and power is supplied from the booster 3 to the smoothing capacitor C2 and the wireless transmitter 9. As a result, the power of the wireless transmission unit 9 is turned on, and the first process S100 is started. When the process S100 is started, the above-described steps S101 to S104 are executed, and the wireless transmission unit 9 waits until the sensor 8 becomes measurable.

  Thereafter, the wireless transmission unit 9 sets a predetermined time interval ΔT of the timer 6 and resets the time count of the timer 6 at the timing P2 at which Step S105 is executed. The time required for the wireless transmission unit 9 to set a predetermined time interval ΔT of the timer 6 from the timing P1 at which the process S100 is started and further to the timing P2 at which the time count of the timer 6 is reset is “waiting time a”. That's it.

  Steps S106 to S115 are executed, measurement data to be wirelessly transmitted is acquired by the sensor 8, and measurement data is read and stored by the wireless transmission unit 9. At timing P3 at which step S116 is executed, the wireless transmission unit 9 performs wireless transmission of the acquired measurement data. The time required from the timing P2 to the timing P3 at which wireless transmission is executed is referred to as “measurement time b”.

  Thereafter, at timing P4 at which step S117 is executed, a timer output OFF signal is transmitted from the wireless transmission unit 9 to the timer 6, and the output of the timer 6 becomes the logical value Low. As a result, the booster 3 and the switching unit S are turned off, the power supply to the wireless transmission unit 9 is stopped, and the power supply of the wireless transmission unit 9 is turned off, so that the first process S100 ends.

  Thereafter, when the timer 6 counts a predetermined time interval ΔT from the timing P2 when the time count of the timer 6 is reset, the output of the timer 6 changes from the logical value Low to the logical value High. Therefore, the booster 3 and the switching unit S are turned on again, and power is supplied from the booster 3 to the smoothing capacitor C2 and the wireless transmitter 9. As a result, the wireless transmission unit 9 starts the second process S100. Thereafter, the above-described process S100 is repeatedly executed until a predetermined number of times of wireless transmission is completed.

  As described above, the wireless transmission device 1 of the present invention executes the setting of the predetermined time interval ΔT of the timer 6 and the reset of the time count of the timer 6 at the timing P2, and further from the timer 6 to the adder 7 at the timing P4. By stopping the output, the ON / OFF control of the booster 3 and the switching unit S can be synchronized with the process S100 (wireless transmission operation) executed by the wireless transmission unit 9.

  Therefore, the connection between the smoothing capacitor C2 and the subsequent component can be cut off while the wireless transmission unit 9 is not executing the process S100, and the power in the smoothing capacitor C2 is reduced by the standby power of the subsequent component. Unnecessary consumption can be prevented. As a result, the inrush current to the smoothing capacitor C2 when the boosting unit 3 and the switching unit S are turned on can be reduced, and the consumption of the electric power stored in the power storage unit C1 can be reduced.

  In step S100, step S105 for setting the time interval ΔT of the timer 6 and resetting the time count of the timer 6 is executed before the timing P3 at which radio transmission is executed, that is, before the radio transmission is executed. The In this case, as shown in the figure, the wireless transmission interval of the wireless transmission unit 9 is defined by time interval ΔT + standby time a + measurement time b−measurement time b = time interval ΔT + standby time a. Independent of b.

  In general, in the process S100 executed by the wireless transmission unit 9, the measurement time b required for the sensor 8 to measure temperature and humidity and the wireless transmission unit 9 to read and store measurement data from the sensor 8 varies most. Cheap. As described above, in the present embodiment, the wireless transmission unit 9 performs the setting of the time interval ΔT of the timer 6 and the reset of the time count of the timer 6 before performing the wireless transmission. It can be made independent of time b. As a result, it is possible to prevent the radio transmission interval of the radio transmission unit 9 from being shifted due to fluctuations in the measurement time b.

  In addition, the power consumption by wireless transmission is the largest among the power consumption by the components after the smoothing capacitor C2. Therefore, by setting the time interval ΔT of the timer 6 and resetting the time count of the timer 6 before executing the wireless transmission, before setting the time interval ΔT of the timer 6 and resetting the time count of the timer 6 Thus, it is possible to reliably prevent the voltage V1 of the power storage unit C1 from being lowered due to wireless transmission and the boosting unit 3 and the switching unit S to be turned off.

  Next, with reference to FIG. 9, the effect of improving energy efficiency by controlling the switching unit S in synchronization with the wireless transmission operation (process S100) will be described.

  FIG. 9 is a diagram showing the voltage V1 of the power storage unit C1, the voltage of the smoothing capacitor C2, and the voltage at the subsequent stage of the switching unit S when wireless transmission is executed nine times after storing 3.0 V of power in the power storage unit C1. It is. FIG. 9A is a diagram illustrating each voltage when the ON / OFF control of the switching unit S synchronized with the above-described wireless transmission operation is not executed. FIG. 9B is a diagram illustrating each voltage when the ON / OFF control of the switching unit S synchronized with the wireless transmission operation is executed. That is, in the example of FIG. 9A, the switching unit S is always in the ON state. On the other hand, in the example of FIG. 9B, the switching unit S is turned ON / OFF in synchronization with the wireless transmission operation.

  In the example of FIG. 9, the operating voltage of the boosting unit 3 is 0.9V to 2.2V, and when the voltage V1 of the power storage unit C1 is within the above-described range, 2.2 V is output from the output terminal VOUT. An output voltage V2 is output. On the other hand, when voltage V1 of power storage unit C1 is higher than 2.2V, an input voltage, that is, a voltage equal to voltage V1 of power storage unit C1 is output from output terminal VOUT.

  First, FIG. 9A will be described. The voltage V1 of the power storage unit C1 stored up to 3.0V in the initial state is consumed by wireless transmission and standby power of each component (resistors R1, R2, sensor 8, wireless transmission unit 9). Among these power consumptions, the power consumption by wireless transmission is the largest, and the portion where the voltage V1 of the power storage unit C1 is discontinuously decreased in FIG. 9A indicates the power consumption by wireless transmission. On the other hand, the portion where the voltage V1 of the power storage unit C1 continuously decreases indicates the power consumption by the standby power of each component. Since the voltage V1 of the power storage unit C1 in FIG. 9A has decreased discontinuously nine times, nine wireless transmissions are executed. In the example of FIG. 9A, the voltage V <b> 1 of the power storage unit C <b> 1 has decreased to about 2.1 V after 9 wireless transmissions have been executed.

  Before the first wireless transmission, the booster 3 is turned off. Therefore, the voltage of the smoothing capacitor C2 and the voltage after the switching unit S are 0V. Thereafter, when the booster 3 is turned on in synchronization with the first wireless transmission operation, power is supplied from the booster 3 to the smoothing capacitor C2 and the wireless transmitter 9. As a result, the voltage of the smoothing capacitor C2 and the voltage after the switching unit S rise. In the example of FIG. 9A, since the switching unit S is always in the ON state, the connection between the smoothing capacitor C2 and the subsequent component is maintained even after the wireless transmission is executed. The voltage at the rear stage of the part S gradually decreases due to the standby power of each component (resistors R1, R2, sensor 8, and wireless transmission unit 9), and finally decreases to about 0.5V. Note that the voltage of the smoothing capacitor C2 decreases with a delay after the voltage at the subsequent stage of the switching unit S.

  Next, FIG. 9B will be described. In the example of FIG. 9B, since the ON / OFF control of the switching unit S is executed in synchronization with the wireless transmission operation, the amount of decrease in the voltage of the smoothing capacitor C2 after the wireless transmission is executed is reduced. I understand. Since the switching unit S is turned off after the wireless transmission is executed, ideally, the voltage of the smoothing capacitor C2 does not decrease. However, as shown in FIG. It decreases slightly due to the leakage current of C2. On the other hand, after the wireless transmission is executed, the switching unit S is turned off, and the connection between the smoothing capacitor C2 and the subsequent component is cut off, so that the voltage after the switching unit S rapidly decreases.

  As described above, in the example of FIG. 9B, the voltage of the smoothing capacitor C2 is kept high during the second and subsequent wireless transmission executions. Therefore, the inrush current to the smoothing capacitor C2 when the boosting unit 3 is turned on decreases, and the amount of decrease in the voltage V1 of the power storage unit C1 during wireless transmission execution decreases. Therefore, as shown in FIG. 9B, the amount of decrease in the voltage V1 of the power storage unit C1 when performing wireless transmission in FIG. 9B is the decrease in the voltage V1 of the power storage unit C1 when performing wireless transmission in FIG. Less than the amount.

  Further, in the example of FIG. 9B, the connection between the smoothing capacitor C2 and the subsequent component is interrupted except when wireless transmission is executed. Therefore, as shown in FIG. 9B, the amount of decrease in the voltage V1 of the power storage unit C1 due to the standby power of the subsequent component in FIG. 9B (the slope of the voltage V1) is the standby of the subsequent component in FIG. Less than the amount of decrease in voltage V1 of power storage unit C1 due to electric power.

  As described above, the ON / OFF control of the switching unit S in synchronization with the wireless transmission operation has the effect of reducing the inrush current to the smoothing capacitor C2 and reducing the power consumption due to the standby power of the subsequent component. It is done. In the example of FIG. 9B, the voltage V1 of the power storage unit C1 after 9 wireless transmissions is about 2.3V, and the voltage drop is reduced compared to the example of FIG. 9A. I understand that. That is, as in the example of FIG. 9B, the energy efficiency of the wireless transmission device 1 can be improved by performing ON / OFF control of the switching unit S in synchronization with the wireless transmission operation.

  As described above, the wireless transmission device and the wireless transmission system of the present invention have been described based on the illustrated embodiments. However, the present invention is not limited to this, and each configuration is an arbitrary one that can exhibit the same function. Can be substituted, or can be added in any configuration.

  In the above-described embodiment, the power generation element 100 is an AC power source that generates alternating current and supplies power to the wireless transmission device 1. However, the present invention is not limited to this, and the power generation element 100 generates direct current. It may be a DC power source that generates power and supplies power to the wireless transmission device 1. In this case, the rectification unit 2 can be omitted from the wireless transmission device 1.

  DESCRIPTION OF SYMBOLS 1 ... Wireless transmission device 2 ... Rectification part 3 ... Boosting part 4 ... Power control part 5 ... Power supply monitoring circuit 6 ... Timer 7 ... Adder 8 ... Sensor 9 ... Wireless transmission part 91 ... Control part 911 ... Processor 912 ... Memory 913 ... Nonvolatile memory 914 ... Volatile memory 92 ... On-chip regulator 93 ... Module 94 ... Non-active mode module 941 ... Mode switching module 942 ... Time count module 95 ... Active mode module 951 ... Interface module 952 ... Sensor control module 953 ... Timer control Module 954 ... Wireless transmission module 10 ... Power generation unit 20 ... Housing 21 ... Cover 22 ... Cylindrical part 23 ... Base 231 ... Through hole 30 ... Magnet assembly 31 ... Permanent magnet 32 ... Back yoke 321 ... Bottom plate 322 ... Cylindrical part 33 ... Yoke 40 ... Coil 50 ... Coil holding part 51 ... Cylindrical part 52 ... Annular part 60U ... Upper leaf spring 60L ... Lower leaf spring 61 ... First annular part 62 ... Second annular part 63 ... Third annular portion 64 ... First spring portion 65 ... Second spring portion 70 ... Spacer 80 ... Washer 90 ... Electrode terminal 100 ... Power generation element 900 ... Wireless transmission system a ... Standby time b ... Measurement time C1 ... Power storage Part C2: Smoothing capacitor D1, D2 ... Diode E ... AC power supply FB ... FB terminal GATE ... Gate terminal IR ... Internal resistance P1-P4 ... Timing Q1, Q2 ... Semiconductor switching elements R1, R2, R3 ... Resistance S ... Switching part S100 ... Processing S101 to S117 ... Step VOUT ... Output terminals V1, V2, V1R ... Voltage

Claims (6)

A wireless transmission device that uses power supplied from a power generation element that generates power using mechanical energy input from outside,
A rectifying unit that converts the power supplied from the power generation element from alternating current to direct current; and
A power storage unit that stores power from the rectifying unit;
A booster that boosts the stored electric power;
A wireless transmission unit that performs a wireless transmission operation using power supplied from the booster; and
A timer for driving the boosting unit at a predetermined time interval,
The wireless transmission device is configured to supply a higher one of the voltage of the power storage unit and the output voltage of the boosting unit to the timer. A first diode connected to the power storage unit; and a second diode connected to the output terminal of the boost unit;
The wireless transmission device according to claim 1, wherein the timer is connected to a junction between an output terminal of the first diode and an output terminal of the second diode.   The wireless transmission device according to claim 1, wherein the timer is connected to the wireless transmission unit so as to be capable of serial communication.   The wireless transmission device according to claim 3, wherein the wireless transmission unit executes the serial communication with the timer in order to reset a time count of the timer before performing wireless transmission.   5. The wireless transmission device according to claim 3, wherein a driving voltage of the boosting unit is set lower than a voltage necessary for driving the timer so that the serial communication is possible. A power generating element that generates power using mechanical energy input from the outside;
A wireless transmission system comprising: the wireless transmission device according to claim 1.

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