JPH10320682A - High-frequency type remote sensor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an oscillation signal level from being too high even in case of a light load or no load. SOLUTION: An oscillation circuit 11 oscillates a pulse signal. A waveform generating circuit 13 generates a drive signal from the pulse signal and also outputs an integral signal of the drive signal. A resonance circuit 17 oscillates a 1st high-frequency signal with the drive signal, and transmits and outputs it to a voltage detecting circuit 19. The voltage detecting circuit 19 outputs a detection signal corresponding to the negative level of the 1st high-frequency signal. A comparing circuit 21 outputs a trigger signal to the waveform generating circuit 13 when the integral signal reaches the detection signal. The waveform generating circuit 13 drives the resonance circuit 17 with 50% duty in its maximum load state and with minimum duty in the no load state according to the input timing of the trigger signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency remote sensor device, and more particularly to an improvement of a high-frequency remote sensor device for wirelessly transmitting a sensor signal obtained by an on / off operation of a switch or detection of an object to be detected.

[0002]

2. Description of the Related Art As a high-frequency type remote sensor device of this type, a configuration including an output unit 1 and a sensor unit 3 as shown in FIG. That is, the output unit 1 electromagnetically transmits and outputs, for example, a first high-frequency signal of, for example, 70 KHz from the resonance circuit 5 including the coil L1 and the capacitor C1, and outputs a second, for example, 455-kHz, electromagnetically transmitted from the sensor unit 3. Is received by the receiving coil L11, a sensor signal superimposed on a plurality of sections within a predetermined synchronization period of the second high-frequency signal is detected, and the light-emitting diodes D1 to Dn are driven to emit light.

On the other hand, the sensor section 3 operates with a drive power supply based on a first high-frequency signal from the output section 1 received by a resonance circuit 7 including a coil L2 and a capacitor C2, and switches a plurality of switches SW1 to SWn individually. A plurality of sections within the synchronization period are made to correspond to the sensor signals of the respective channels, and the oscillation operation of the second high-frequency signal is turned on in those sections based on the sensor signals input by the ON operation of the individual switches SW1 to SWn. Alternatively, the second high-frequency signal is electromagnetically transmitted and output from the transmission coil L21.

In such a high-frequency type remote sensor device, the driving power of the sensor unit 3 is wirelessly supplied by the first high-frequency signal transmitted electromagnetically from the resonance circuit 5 of the output unit 1, and the second power is supplied to the sensor unit 3. The sensor signal is put on the high frequency signal of the transmission coil L21 and the output unit 1
From the second high-frequency signal received by the receiving coil L11 of the output unit 1,
On / off of Wn is remotely detected.

[0005]

However, the output unit 1 of the high-frequency remote sensor device described above applies a square wave to the resonance circuit 5 from a built-in drive circuit (not shown in FIG. 5) to generate a first high-frequency signal. In order to oscillate the signal and efficiently supply the driving power, the configuration is such that the pulse is oscillated with a pulse signal having a duty ratio of 50% (1: 1). Therefore, when the sensor unit 3 as a load viewed from the resonance circuit 5 in the output unit 1 is not electromagnetically coupled or the load in the sensor unit 3 is lightened, the first high-frequency signal in the resonance circuit 5 The level greatly increases, the voltage between both ends of the capacitor C1 forming the resonance circuit 5 exceeds its withstand voltage, which easily damages the capacitor, and the current consumption increases.

On the other hand, the sensor unit 3 also includes an output unit 1
Is constant, the driving power supply level based on the first high-frequency signal induced by the resonance circuit 7 decreases when the current consumption in the sensor unit 3 is large, and conversely, when the current consumption is small, the driving Since the power supply level rises, the internal drive voltage fluctuates due to fluctuations in the load, which is not preferable from the viewpoint of ensuring reliable operation. However, in the sensor section 3, for example, a Zener diode (not shown) is connected to the resonance circuit 7, and when the driving power supply level from the resonance circuit 7 exceeds a predetermined reference level, the Zener diode consumes extra power. A technique for stabilizing the supply voltage from the power supply 7 has also been proposed.

However, in such a configuration, it is necessary to take measures to dissipate heat in the Zener diode. In addition, the sensor unit 3 always consumes a large amount of power, and the output unit 1 always consumes the largest current. Goes against the trend of electrification. Then, the present inventor has compared and examined the relationship between the resonance circuits 5 and 7 in the output unit 1 and the sensor unit 3 and the fluctuation of the load. As a result, the first high-frequency signal oscillated by the resonance circuit 5 and the resonance circuit 7 In both the driving power supplies based on the induced first high-frequency signal, the voltage level is close to a sine wave when the load is light or no load, while the voltage level is low and negative when the load is heavy or maximum load. The present invention was completed by paying attention to the point that a signal waveform in which the half-wave is collapsed.

The present invention has been made under such a circumstance, and is intended to provide a high-frequency type remote sensor device in which the oscillation signal level of the output section and the drive power level of the sensor section do not become too high in response to a change in load. For the purpose of providing.

[0009]

In order to solve such a problem, a first configuration according to the present invention operates with a drive power supply based on an output signal from a resonance circuit that resonates with a first high-frequency signal, A second frequency separated from the first high-frequency signal
A high-frequency signal and a second high-frequency signal that is controlled based on the sensor signal. The first high-frequency signal is electromagnetically supplied to the sensor unit from a resonance circuit, and is transmitted. An output unit for detecting the sensor signal from the second high-frequency signal. The output unit oscillates the first high-frequency signal in a resonance circuit of the output unit, and outputs the first high-frequency signal. When the negative level of the high-frequency signal exceeds the predetermined reference level and increases to the negative side, the oscillation level of the first high-frequency signal is suppressed.

A second configuration according to the present invention operates with a drive power supply based on an output signal from a resonance circuit that resonates with the first high-frequency signal, and operates at a second frequency separated from the first high-frequency signal. A sensor unit for electromagnetically transmitting a second high-frequency signal, which is a high-frequency signal controlled based on the sensor signal, and electromagnetically supplying the first high-frequency signal to the sensor unit from a resonance circuit and transmitting the signal. An output unit for detecting a sensor signal from the second high-frequency signal, wherein the drive power supply that has risen above a predetermined control reference level falls and reaches the control reference level. In this case, the resonance frequency of the resonance circuit is shifted for a predetermined period. In the second configuration, the resonance frequency of the resonance circuit of the sensor unit is set to the first frequency.
It is preferable to form the sensor section so as to shift the frequency to a higher frequency than the high frequency signal.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram showing an output unit as a first configuration according to the high-frequency type remote sensor device of the present invention, and FIG. 2 is a timing waveform diagram for explaining the operation. A to F in FIG. 2 show operation waveforms in a no-load state,
A to f in the same figure show operation waveforms in the maximum load state.

In FIG. 1, an output unit 9 is an oscillation circuit 1
1, waveform shaping circuit 13, drive circuit 15, resonance circuit 1
7, a voltage detection circuit 19 and a comparison circuit 21. The oscillating circuit 11 oscillates an equal-pulse oscillating signal having a short off-period as a timing clock and outputs the oscillating signal to the waveform shaping circuit 13 as shown in FIG. 2A, for example. FIG. 2A also shows an oscillation signal similar to FIG.

The waveform shaping circuit 13 shapes a pulse-shaped drive signal which is turned on by an off timing of an oscillation signal from the oscillation circuit 11 and turned off by an input timing of a trigger signal (timing signal) from a comparison circuit 21 described later. This is output to the drive circuit 15. Therefore, from the waveform shaping circuit 13,
It is possible to output a drive signal whose duty ratio is changed in accordance with a change in the input timing of the trigger signal.

For example, as shown in FIGS. 2B and 2B, a drive signal having a maximum duty ratio (50%) in a maximum load state, a drive signal having a small duty ratio as the load decreases, and a duty signal in a no-load state. The drive signal with the smallest ratio is output. However, the waveform shaping circuit 13 is configured to output a drive signal having a duty ratio of 50% at the maximum even without input of a trigger signal from the comparison circuit 21.

The waveform shaping circuit 13 forms an integrated signal which rises in signal level transiently with the elapse of the ON period of the drive signal and turns off when the drive signal is turned off, and outputs this to the comparison circuit 21. Has become. [Please confirm. Therefore, from the waveform shaping circuit 13, for example, FIG.
In the maximum load state, an integrated signal for a positive half cycle of a first high-frequency signal described later is output, and an integrated signal for a shorter period is output as the load decreases,
In a no-load state, a minimum integration signal is output.

The drive circuit 15 amplifies the drive signal and outputs the amplified drive signal to the resonance circuit 17. Resonant circuit 17
Is formed of a parallel LC resonance circuit of a coil L1 and a capacitor C1, and has a predetermined resonance frequency, for example, 70 KHz.
And oscillates a first high-frequency signal in response to a drive signal from the drive circuit 15.

As shown in FIG. 2C, the waveform of the first high-frequency signal oscillated by the resonance circuit 17 has a positive half-wave level lower than that of the first high-frequency signal under the maximum load condition (0). As the waveform approaches the level, the negative level becomes short and the signal waveform becomes short, and in a no-load state, as shown in FIG. Is output to the voltage detection circuit 19 and is electromagnetically transmitted to the sensor unit 23 described later. That is, the waveform of the first high-frequency signal oscillated by the resonance circuit 17 changes according to the change in the load of the resonance circuit 17.

The voltage detection circuit 19 rectifies and smoothes the negative half-wave level of the first high-frequency signal, which is the oscillation signal in the resonance circuit 17, and compares the detection signal corresponding to the negative level with the comparison circuit 21.
For example, if a negative power supply voltage is supplied to the output unit 9, since the negative half-wave level is small at the maximum load, a high-level detection signal as shown in FIG. When no load is applied, since the negative half-wave level of the first high-frequency signal is large, a low-level detection signal is output as shown in FIG. 2E. FIGS. 2E and 2E show a state in which a slight sawtooth wave component is included.

The comparison circuit 21 compares the integration signal from the waveform shaping circuit 13 with the detection signal from the voltage detection circuit 19, and outputs a trigger signal to the waveform shaping circuit 13 when the integration signal reaches the detection signal. It has become. The waveform shaping circuit 13, the voltage detection circuit 19, and the comparison circuit 21 generate a drive signal having a maximum duty ratio (50%) from the waveform shaping circuit 13 at the maximum load, and a drive signal having a minimum duty ratio at no load. It is formed to be output. The second example described in the conventional example
Since the high-frequency signal is not directly related to the configuration of the present invention,
The description is omitted (the same applies hereinafter).

Next, the operation of the first configuration shown in FIG. 1 will be described. First, when power is supplied to the output unit 9, a drive signal that is turned on by turning off an oscillation signal (FIG. 2A) from the oscillation circuit 11 is transmitted from the waveform shaping circuit 13 to the drive circuit 15
And the resonance circuit 17 is turned on.
1 does not output a trigger signal, and a drive signal having a duty ratio of 50% as shown in FIG. 2B is applied from the waveform shaping circuit 13 to the resonance circuit 17.

The waveform shaping circuit 13 outputs an integrated signal as shown in FIG. 2D to the comparison circuit 21, while the resonance circuit 17 oscillates and outputs a first high-frequency signal as shown in FIG. The signal is output to the detection circuit 19 and is electromagnetically transmitted to a sensor unit 23 described later. The voltage detection circuit 19 detects the negative half-wave level of the first high-frequency signal, and applies a high-level detection signal as shown in FIG.

The comparison circuit 21 compares the integration signal as shown in FIG. 2D with the detection signal as shown in FIG. 2E. When the integration signal reaches the detection signal, a trigger signal as shown in FIG. Therefore, when the resonance circuit 17 is in the maximum load state, the resonance circuit 17 is continuously driven by the drive signal having the duty ratio of 50%. Thereafter, when the load on the resonance circuit 17 is reduced, the level of the negative half-wave is increased together with the positive half-wave of the high-frequency signal resonating in the resonance circuit 17, and the level of the detection signal output from the voltage detection circuit 19 is reduced. This reaches the detection signal before the level of the integrated signal from the shaping circuit 13 increases, and the trigger signal is output to the waveform shaping circuit 13 at an early timing.

Therefore, the drive signal from the waveform shaping circuit 13 is turned off earlier than in the maximum load state, and the resonance circuit 17 is oscillated by the drive signal having a small duty ratio. Further, when no load occurs, the resonance circuit 1
7, the level of the negative half-wave of the first high-frequency signal further increases, the level of the detection signal output from the voltage detection circuit 19 becomes the lowest, and the trigger signal is output immediately after the integration signal is output from the waveform shaping circuit 13. The drive signal which is output to the waveform shaping circuit 13 and has the smallest duty ratio is added to the resonance circuit 17.

Conversely, when the load changes from the no-load state to the maximum load state, the level of the detection signal from the voltage detection circuit 19 rises, the timing at which the integration signal exceeds this level is delayed, and the output timing of the trigger signal is also delayed. , Waveform shaping circuit 1
The duty ratio of the drive signal from 3 also increases.
That is, the negative half-wave level of the first high-frequency signal which fluctuates according to the fluctuation of the load is detected,
Then, the integrated signal is compared as a reference level, and when the negative half-wave level of the first high-frequency signal exceeds the reference level and increases to the negative side, the rise of the oscillation level of the first high-frequency signal is suppressed. .

In the first configuration thus configured, in the output section 9, a pulse-like drive signal is applied from the drive circuit 15 to oscillate the first high-frequency signal in the resonance circuit 17 and the first high-frequency signal is oscillated. When the negative half-wave level of the high-frequency signal exceeds the reference level and increases to the negative side, the on-period of the drive signal is formed so as to be able to be varied shortly. In a no-load state, such as when the load is extremely light, or in a state close to this, the level of the first high-frequency signal oscillated by the resonance circuit 17 does not increase so much, and the voltage across the capacitor C1 forming the resonance circuit 17 increases. It is difficult to exceed the withstand voltage and it is hard to be damaged. Therefore, it is possible to use an inexpensive capacitor C1 having a high withstand voltage, to reduce cost and to reduce current consumption.

In the above-described first configuration, the negative half-wave level of the first high-frequency signal is detected, and this is detected by the waveform shaping circuit 13.
Although the comparison is made using the integral signal as the reference level, a predetermined fixed reference level may be set, and the negative half-wave level of the first high-frequency signal may be compared with the fixed reference level.

Next, a description will be given of a sensor unit as a second configuration according to the high-frequency remote sensor device of the present invention. FIG. 3 is a schematic block diagram showing the sensor section 23 having the second configuration, and FIG. 4 is a timing waveform chart for explaining the operation thereof. Note that GI in FIG. 4 indicate operation waveforms in a no-load state, and g to i in FIG. 4 indicate operation waveforms in a maximum load state.

In FIG. 3, the sensor section 23 includes a resonance circuit 25, a rectifier circuit 27, an output circuit 29, and a voltage detection circuit 3.
1, a comparison circuit 33 and a switch circuit 35. The resonance circuit 25 is formed of a series circuit of a coil L2 and capacitors C2 and C3 connected in parallel to both ends of the coil L2, and is connected to the rectifier circuit 27. A diode D is connected in parallel to both ends of the capacitor C3 together with a switch circuit 35 that opens or shorts the capacitor C3.

The resonance circuit 25 resonates with the first high-frequency signal by the capacitor C2 and the coil L2 when the capacitor C3 is short-circuited. When the short-circuit of the capacitor C3 is released, the capacitor C2 , C
3 and the coil L2, so as to resonate at a resonance frequency higher than the first high-frequency signal, for example, 200 KHz. The first high-frequency signal level induced by the resonance circuit 25 and applied to the rectification circuit 27 is shown in FIGS. As shown in
It is high under no load and low under maximum load. In the no-load state, the first high-frequency signal is output every certain period as described later, but the details will be described later.

The rectifier circuit 27 is connected to the first
Rectifying and smoothing the high-frequency signal to output a driving power supply. The driving power supply is connected to an output circuit 29, a voltage detection circuit 31, and a comparison circuit 33. As shown in FIGS. It is high in the state and low in the maximum load state. In FIGS. 4H and 4H, the waveforms include a slight pulsating component.

The output circuit 29 supplies drive power to a sensor circuit (not shown) that detects an object to be detected and outputs a sensor signal. The drive power is supplied to a voltage level sufficient for driving the sensor circuit. It has a function of supplying drive power to the sensor circuit after rising. Therefore, when the output unit 9 is powered on, the sensor unit 23
Even if the drive voltage from the rectifier circuit 27 is low, the sensor circuit as a load is not connected, so that the drive power supply level quickly rises, and this is the voltage detection circuit 31 and the comparison circuit 3
3.

The voltage detecting circuit 31 is a voltage dividing circuit such as a resistor, and detects the driving power supply voltage from the rectifying circuit 27 to divide the voltage.
This detection signal is output to the comparison circuit 33. When the drive power supply level from the rectifier circuit 27 exceeds a startup reference level (not shown), the comparison circuit 33 switches the switch circuit 35 over a plurality of cycles of the first high-frequency signal, for example.
Is output to the switch circuit 35, and as shown in FIG. 4h, when the detection signal from the voltage detection circuit 31 does not exceed the control reference level and is small, the switch circuit 35 is continuously operated. As shown in FIG. H, when the detection signal which has increased beyond the control reference level decreases to reach the control reference level, the first high-frequency signal is turned on. A control signal for turning on a signal, for example, about a positive half cycle, is output to the switch circuit 35.

The switch circuit 35 includes an FET transistor Q having a drain connected to a connection point between the capacitors C2 and C3, and a source connected to a connection point between the coil L2 and the capacitor C3. And a control signal is applied to the gate to perform an ON operation (short circuit between the drain and the source). The diode D, which is connected in the forward direction between the source and the drain of the FET transistor Q, is for preventing the negative half wave from being applied to the drain when the FET transistor Q is turned on, thereby preventing malfunction.

Next, the operation of the second configuration shown in FIG. 3 will be described. First, when the output unit 9 is powered on, the output unit 9
The first high-frequency signal is electromagnetically transmitted from the resonance circuit 17 of the first embodiment, and the first high-frequency signal is induced by the resonance circuit 25 of the sensor unit 23.

However, since both ends of the capacitor C3 are open and the resonance circuit 25 resonates at a resonance frequency higher than the first high-frequency signal, the induced voltage does not increase so much. Although the drive power level thus obtained is low and drive power is not supplied from the output circuit 29 to the sensor circuit, the drive power from the rectifier circuit 27 rises quickly and is applied to the voltage detection circuit 31 and the comparison circuit 33.

The comparison circuit 33 compares the drive power supply level from the rectifier circuit 27 with the start reference level, and when the drive power supply exceeds the start reference level, outputs a start signal to the switch circuit 3.
5, the switch circuit 35 is turned on for a plurality of cycles of the first high-frequency signal, and the resonance circuit 25
, While driving power is supplied from the output circuit 29 to the sensor circuit. Therefore, the resonance circuit 2
5, the first high-frequency signal level is strongly induced, but since the driving power is supplied to the load side, the input signal level to the rectifier circuit 27 does not increase so much as shown in FIG.

The driving power supply is connected to the voltage detecting circuit 31.
Is output to the comparison circuit 33, and the comparison signal compares the detection signal from the voltage detection circuit 31 with the control reference level. Since the detection signal is smaller than the control reference level, as shown in FIG. , A control signal in which the ON state continues is output to the switch circuit 35, the switch circuit 35 continues to short-circuit the capacitor C3, and the first high-frequency signal level continues to be strongly induced in the resonance circuit 25, so that the drive power supply is supplied to the load side. Maximum supply.

On the other hand, when there is no load, the rectifier circuit 27
The input signal level to the rectifier circuit 27 and the drive power supply level from the rectifier circuit 27 rise, and the detection signal from the voltage detection circuit 31 exceeds the control reference level, so that the control signal is turned off and the switch circuit 35 is turned off. , Resonance circuit 25
Is in a resonance frequency state higher than that of the first high-frequency signal, and an increase in the induced level of the first high-frequency signal is suppressed. Then, when the detection signal from the voltage detection circuit 31 decreases and reaches the control reference level as the drive power supply level from the rectifier circuit 27 decreases in the no-load state, the comparison circuit 33 outputs the first high-frequency signal. A control signal for turning on the switch circuit 35 for a positive half cycle is output, and after the resonance circuit 25 resonates with the first high-frequency signal, the resonance frequency is shifted again. It continues until the detection signal falls below the control reference level.

That is, the detection signal from the voltage detection circuit 31 decreases to reach the control reference level, and resonates with the first high-frequency signal for a positive half cycle of the first high-frequency signal.
Until the detection signal from the voltage detection circuit 31 falls again and reaches the control reference level, the rise of the first high-frequency signal is suppressed. Then, between the maximum load state and the no-load state, the drive signal level from the rectifier circuit 27 increases as the load decreases, and the drive signal level from the rectifier circuit 27 decreases as the load increases. The period during which the first high-frequency signal resonates in the positive half cycle of the high-frequency signal changes according to the load, and the rise of the first high-frequency signal in the resonance circuit 25 is suppressed.

As described above, the second configuration according to the present invention is as follows.
In the sensor unit 23 that operates with the drive power supply induced by the resonance circuit 25 that resonates with the first high-frequency signal electromagnetically transmitted from the output unit 9, the level of the first high-frequency signal induced by the resonance circuit 25 is a predetermined level. Since the resonance frequency of the resonance circuit 25 is shifted when it rises above the control reference level, the rise of the first high-frequency signal of the resonance circuit 25 is suppressed even when the load on the sensor unit 23 is reduced, and the drive is performed. Power supply is stabilized. Therefore, in the sensor unit 23,
When the load is reduced as in the conventional case, it is not necessary to consume extra power by using a Zener diode or the like, and it is not necessary to take measures to dissipate heat such as a Zener diode. As the power becomes lighter, the power consumption of the sensor unit 23 itself decreases and the power consumption of the output unit 9 side is also suppressed.

By the way, in the second configuration, when the load becomes light, one of the capacitors C2 and C3 connected in series is short-circuited to shift to a frequency higher than the first high-frequency signal.

However, although not shown, in the second configuration of the present invention, it is possible to open one of the capacitors C2 and C3 to shift the frequency to a lower frequency than the first high-frequency signal. When the load is reduced in the resonance circuit 25 in which the parallel circuit is connected in parallel to the coil L2, one of the capacitors C2 and C3 is connected or disconnected from the coil L2 to shift the frequency to a frequency higher or lower than the first high-frequency signal. It is also possible to form it. However, if the frequency is shifted to a higher frequency than the first high-frequency signal, there is an advantage that it is possible to use capacitors C2 and C3 which are small, inexpensive and have relatively low withstand voltage.

The frequency shifted from the first high-frequency signal is arbitrary as long as its oscillation level or induced level does not increase so much even when there is no load.
Further, in the second configuration, the switch circuit 35 for shifting the resonance frequency of the resonance circuit 25 is formed from the FET transistor Q. However, this switch circuit 35 is a mechanical switch circuit such as a known electronic non-contact circuit or a relay. Can be formed.

[0044]

As described above, in the first configuration according to the present invention, in the output section that electromagnetically supplies the first high-frequency signal to the sensor section from the resonance circuit, the output section uses the resonance circuit of the output section. The first high-frequency signal is oscillated, and when the negative level of the first high-frequency signal exceeds a predetermined reference level and increases to the negative side, the first high-frequency signal is formed so as to suppress the oscillation level of the first high-frequency signal. Even if the load on the resonance circuit of the unit is reduced or no load is applied, it is possible to suppress an increase in the oscillation level of the first high-frequency signal. Therefore, it is not necessary to increase the withstand voltage of the capacitor forming the resonance circuit of the output unit, so that an inexpensive capacitor can be used, and current consumption can be suppressed. Further, according to the second configuration of the present invention, in the sensor section operating with the drive power supply based on the first high-frequency signal from the output section, the drive power supply level exceeding a predetermined control reference level is reduced and the control reference level is reduced. Since the resonance frequency of the resonance circuit is shifted when the level reaches the level, the driving power supply in the sensor unit can be stabilized even if the load on the sensor unit is reduced or no load is applied. Therefore, it is not necessary to use a Zener diode or the like to consume extra power when the load is reduced as in the conventional case. Is not maximized, which is preferable from the viewpoint of power saving. Then, in the second configuration, the first
In the configuration in which the resonance circuit of the sensor section is formed so as to shift to a frequency higher than the high-frequency signal of the above, there is an advantage that the withstand voltage of the capacitor forming the resonance circuit does not need to be increased and a small-sized one can be used. .

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a first configuration according to a high-frequency remote sensor device of the present invention.

FIG. 2 is a timing waveform chart for explaining the operation of the high-frequency remote sensor device of FIG.

FIG. 3 is a schematic block diagram showing a second configuration of the high-frequency remote sensor device of the present invention.

FIG. 4 is a timing waveform chart for explaining the operation of the high-frequency remote sensor device of FIG. 3;

FIG. 5 is a block diagram illustrating a general configuration of a high-frequency remote sensor device.

[Explanation of symbols]

 1, 9 output unit 3, 23 sensor unit 5, 7, 17, 25 resonance circuit 11 oscillation circuit 13 waveform shaping circuit 15 drive circuit 19, 31 voltage detection circuit 21, 33 comparison circuit 27 rectification circuit 29 output circuit 35 switch circuit C1 , C2, C3 Capacitors L1, L2, L11, L21 Coil Q FET transistor SW1 to SWn Switch D1 to Dn Light emitting diode

Claims (3)

[Claims] A first high-frequency signal that operates on a drive power supply based on an output signal from a resonance circuit that resonates with the first high-frequency signal, the second high-frequency signal being separated from the first high-frequency signal by a sensor signal; A sensor for electromagnetically transmitting a controlled second high-frequency signal; and a sensor for electromagnetically supplying the first high-frequency signal to the sensor from a resonance circuit; and transmitting the second high-frequency signal to the sensor from the transmitted second high-frequency signal. And an output unit for detecting a signal. The high-frequency remote sensor device, comprising:
And oscillates the high-frequency signal, and suppresses the oscillation level of the first high-frequency signal when the negative level of the first high-frequency signal exceeds a predetermined reference level and increases to the negative side. And high frequency type remote sensor device. A second high-frequency signal operating at a driving power source based on an output signal from a resonance circuit resonating with the first high-frequency signal, the second high-frequency signal being separated from the first high-frequency signal based on a sensor signal; A sensor for electromagnetically transmitting a controlled second high-frequency signal; and a sensor for electromagnetically supplying the first high-frequency signal to the sensor from a resonance circuit; and transmitting the second high-frequency signal to the sensor from the transmitted second high-frequency signal. An output unit for detecting a signal, wherein the sensor unit comprises: when the drive power supply level that has risen above a predetermined control reference level decreases and reaches the control reference level, A high-frequency type remote sensor device formed so as to shift the resonance frequency of the resonance circuit for a predetermined period. 3. The high-frequency remote sensor device according to claim 2, wherein the sensor unit is formed to shift a resonance frequency of the resonance circuit of the sensor unit to a frequency higher than the first high-frequency signal.