JP3285326B2 - Electronic circuit with radio wave detection function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit having a function of detecting the arrival of radio waves, and more particularly to an electronic circuit for preventing malfunction of a proximity switch due to radio waves.
The present invention relates to a suitable electronic circuit having a radio wave detection function .

[0002]

2. Description of the Related Art For example, in a pachinko machine, an electromagnetic induction type pachinko ball sensor comprising a proximity switch is used to detect that a pachinko ball has entered a winning opening. The pachinko ball sensor of this type detects that a pachinko ball, which is a metal body, has passed through the winning opening without contact using an electromagnetic induction effect. In addition, a contact type and an optical type have been put to practical use.

Among them, the contact-type pachinko ball sensor is
This is a method in which the movable piece is displaced by passing the pachinko ball to turn on and off the contact mechanism, but has disadvantages such as a short life due to wear of the contact portion and a chattering phenomenon easily occurring. In addition, the optical pachinko ball sensor changes the amount of light received by the light receiving element by interrupting the optical path between the light emitting element and the light receiving element by passing the pachinko ball, but this method uses disturbance light. , There is a disadvantage that malfunction is likely to occur. Therefore, conventionally, the pachinko ball sensor of the electromagnetic induction type has been used in many machines because it is considered to be excellent in terms of life, and is least likely to be affected by external factors, and has the highest reliability.

FIG. 9 shows the appearance of a pachinko ball sensor 11 of this type. In the figure, a detection hole 13 having a hole diameter through which a pachinko ball 14 can pass is formed through a thin plate-shaped synthetic resin case body 12 in the thickness direction. In this case body 12, a detection circuit section 19 of a proximity switch is incorporated on one side of the detection hole 13, and an oscillation coil L of an oscillation circuit forming a part of the detection circuit section 19 is provided around the detection hole 13. Have been.

FIGS. 10 and 11 show the principle of a proximity switch incorporated in the pachinko ball sensor 11. FIG. 10 (1), when the metal body 15 to the oscillation coil L now is located at a distance _{l 1} that well away, the oscillation circuit 16 is oscillating operation, FIG. 1 as its output _{V OUT}
An output waveform as shown in 0 (2) is obtained.

[0006] Next, as shown in FIG.
When 5 approaches to the position of the distance l ₂ with respect to the oscillation coils L, since the metal body 15 is an eddy current by electromagnetic induction is generated in its interior receives magnetic lines of oscillation coils L, the oscillation coil L
Oscillation stops due to the increase in the resistance of
_OUT has a waveform as shown in FIG.

As the oscillating circuit 16, a separate Hartley oscillating circuit as shown in FIG. 12 is used. The oscillation circuit 16, the transistor TR ₁₂ for amplification which was electrically connecting the LC resonant circuit 17 and resistor R _12, the operating point is an active region of the transistor TR ₁₂ by the constant current source 21 and the bias voltage V _S of the drawing Is compensated for. The transistors TR ₁₃ and TR _{14 form} a mirror circuit, and feed back the same current as the collector current of the transistor TR ₁₂ to the LC resonance circuit 17. V _CC is the power supply voltage, and V _CC
OUT indicates an output, and G indicates ground.

When the metal body 15 approaches or separates from the proximity switch including the oscillation circuit 16 as shown in FIG. 13, the output _VOUT has a signal waveform as shown in FIG. If this signal is integrated and binarized by a predetermined threshold value, a detection signal S which rises in response to the approach of the metal body 15 as shown in FIG.

Thus, when the pachinko ball detection sensor 11 is configured by using such a proximity switch, a detection signal S is output each time the pachinko ball 14 passes through the detection hole 13, whereby the pachinko ball enters the winning opening. It can be detected that it has entered.

[0010] As the oscillation circuit 16, a Colpitts type as shown in FIG. 15 can be used instead of the Hartley type. This Colpitts-type oscillation circuit 16 uses two capacitors C ₁ and C ₂ for the oscillation coil L,
The C resonance circuit 20 is configured, and an LC resonance circuit 20 and a plurality of resistors R _{13 to} R ₁₅ are electrically connected to two transistors TR ₁₅ and TR ₁₆ .

[0011]

In a pachinko machine using the above-mentioned pachinko ball sensor 11, some of the players perform misconduct, and the pachinko ball sensor 11 is erroneously operated to illegally deceive the pachinko ball. are doing. That is, a radio wave is emitted toward the pachinko ball sensor 11 located at the winning opening, and the pachinko ball sensor 11 malfunctions as if the pachinko ball detected the pachinko ball even though the pachinko ball was not in the winning opening. Let it do.

[0012] The malfunction is believed to be due to the internal capacitance 18 of the transistor _{TR 12} in the oscillation circuit 16, a radio wave that has reached the oscillation circuit 16 from the oscillation coil L reaches the base of the transistor _{TR 12} via the internal capacitance 18 it makes potential drops across the internal volume 18, the base of the transistor TR ₁₂ - no longer applied a sufficient voltage V _bE between the emitters, transistor TR
₁₂ turns off.

The present invention has been made in view of the above circumstances, and has a transistor for detecting the arrival of radio waves.
Radio wave detection suitable for applications such as preventing erroneous operation due to radio waves of the proximity switch by using an ion connection
It is an object to provide an electronic circuit with a function .

[0014]

A radio wave detecting function according to the present invention
An electronic circuit with a transistor and a transistor
A voltage detecting unit for detecting a drop in the voltage between terminals is provided. Previous
The transistor is diode-connected and one terminal connected to the diode is connected to the ground potential side of the electronic circuit , and the other terminal is connected to the power supply potential side of the electronic circuit.
Have been. The voltage detector detects the arrival of a radio wave by detecting a decrease in the voltage between the terminals of the transistor.
In the invention according to claim 2, the electronic circuit has an output circuit.
When the electronic detection unit detects the arrival of radio waves,
A prohibition signal is sent to the output circuit, and the output circuit outputs the prohibition signal.
The output is stopped when a stop signal is received.

[0015]

When a radio wave arrives, the radio wave reaches the transistor through the internal capacitance of the transistor. For this reason, the voltage between the terminals at both ends of the internal capacitance decreases, and the voltage detection unit detects this voltage decrease, and thereby the arrival of the radio wave is detected. In the electronic circuit with a radio wave detection function according to claim 2,
When the arrival of the radio wave is detected by the voltage detection unit, the output circuit
The output is stopped in response to the prohibition signal from the voltage detector.

[0016]

FIG. 1 shows a detection circuit section 1 of a pachinko ball sensor to which the present invention is applied. However, the radio wave detection device of the present invention is not limited to the pachinko ball sensor, but can be applied to other applications. Of course. The appearance of the pachinko ball sensor is the same as that shown in FIG. 9, and illustration and description thereof are omitted here.

The detection circuit section 1 shown in FIG. 1 is configured by electrically connecting an integration / comparison circuit 3 and an output circuit 4 to an oscillation circuit 2 including an LC resonance circuit 6. A radio wave detection circuit unit 7 is provided in addition to the known object detection circuit unit 5.

The oscillating circuit 2 oscillates when the pachinko ball, which is a metal body, is far away, and stops the oscillating operation when approaching. The object detection circuit section 5 responds to this oscillation and the stop of the oscillation. The passage of the ball through the detection hole 13 is detected. FIG. 2A shows the output V of the object detection circuit 5.
_OUT-1 is shown, and an oscillation waveform appears corresponding to the approach and separation of the pachinko ball.

The radio wave detection circuit section 7 detects the arrival of radio waves, generates a prohibition signal, and supplies the prohibition signal to the output circuit 4. 2 (2) is an output V _{O UT-2} of the radio wave detection circuit unit 7, prohibiting signal K in response to the arrival of a radio wave is turned on. Note that the object detection circuit unit 5 is also sensitive to the arrival of a radio wave, and as shown by the broken line in FIG. 2A, the oscillation waveform disappears when the radio wave arrives.

The integration / comparison circuit 3 integrates the output _VOUT-1 of the object detection circuit section 5, compares it with a predetermined threshold value, and binarizes it as shown in FIG. Output V
_{OUT- 3} is obtained.

The output circuit 4 is a gate for restricting the passage of the output _VOUT-3 by the inhibition signal K. Only when the inhibition signal K is off, the output V of the integration / comparison circuit 3 is output. _OUT-3 . Fig. 2 (4)
Is the final output _{VOUT from the} output circuit 4, and the detection signal S is turned off at the arrival time a of the radio wave. In the figure, b indicates a malfunction area where the object detection circuit unit 5 has performed a detection operation due to the arrival of a radio wave even though the pachinko ball is not approaching. Is blocked.

FIG. 3 shows a specific example of the oscillating circuit 2 using a separate type Hartley oscillating circuit. The object detecting circuit section 5 detects an approach of a pachinko ball, and detects the arrival of a radio wave. And a radio wave detection circuit section 7 for the purpose.

[0023] The object detection circuit 5, LC resonant circuit 6 to a transistor _TR 1, TR ₂ for amplification, a resistor _{R 1,} and the volume resistivity VR those formed by electrically connecting the transistor TR ₁ is the base and the collector Are short-circuited and diode-connected. The constant current source 8 shown in FIG. ₃ applies a bias to the transistors TR ₁ and TR ₂ , and the transistors TR _{3 to} TR ₅ form a feedback circuit. Transistor T
R ₃ and TR ₄ form a mirror circuit, and LC resonance circuit 6
To be fed back the same current as the collector current of the transistor TR _2.

Next, the radio wave detection circuit section 7 includes two transistors TR ₆ and TR ₇ and a plurality of resistors R _{2 to} R _5, and the transistor TR ₁ of the object detection circuit section 5 includes:
Transistor TR ₆ to the base via a resistor R ₂ is is connected. This transistor TR ₆ is
₁ base - the voltage _{V BE1} of the emitter be an active circuit for the bias, the transistor TR ₆ base - voltage _{V B E6} between the emitter and the voltage drop component of the resistor _{R 2} and _{V R2,} the following The relationship holds. V _BE1 = V _BE6 + V _R2

[0025] Therefore, the collector current _{I C6} of the collector current _{I 0} and the transistor TR ₆ of the transistor TR ₁ during steady-state operation becomes a relationship of _I 0 >> _{I C6,} the operating point of the transistor TR ₆ is than that of the transistor TR ₁ Is also located on the side of the blocking area. Therefore, the base of the transistor TR ₁ - In Sagare voltage _{V BE1} of the emitter region for some reason, before the transistor TR ₁ is shifted to the off state, the transistor TR ₆ is turned off.

FIG. 6 shows the potentials V ₁ and V ₅ of the base and the emitter of the transistor TR ₁ and the output V _OUT-1 of the object detection circuit section 5. FIG. 6 (2) shows a voltage waveform when the oscillation operation is stopped, and FIG. 6 (2) shows a voltage waveform when the metal body is oscillating apart. According to FIG. 6 (2), the base potential _{V 1} of the transistor TR ₁ is _(R 1 · _I 0 +
V _BE1 ), the emitter potential V ₅ is centered on the R ₁ · I ₀ voltage level, and the output V _OUT-1 is centered on 0 volt, and the oscillation amplitude is centered on each. .

[0027] Thus, since the transistor TR ₆ of the radio wave detection circuit 7 takes the potential _V 1, _{V 5,} its base - the voltage _{V BE6} of the emitter is constant, the collector current _{I C6} theoretically constant ( Actually, an oscillating pulsation flows).

Therefore, the voltage (R ₄ · I) across the resistor R ₄ is obtained.
_C6 ), R ₄ · I _C6 > 0.6 volts (about 1 volt)
, The transistor TR ₇ is connected to the object detection circuit 5
Is turned on both when the device is oscillating and when the device stops oscillating.

[0029] FIG. 7 shows the potential _{V 3} of the collector of the base potential _{V 4} and the transistor TR ₆ of the transistor TR _7, FIG. 7 (1) The voltage waveform during oscillation stop, Figure 7 ( 2) shows voltage waveforms during oscillation, respectively. Note that according to FIG. 7 (2), is slightly oscillating pulsating current riding to the potential V ₃ of the collector of the transistor TR _6.

Next, the operation of the oscillation circuit 2 will be described with reference to a time chart shown in FIG. Now, when a metal body such as a pachinko ball is separated from the oscillation coil L, the oscillation circuit 2 performs an oscillation operation, and the voltage of each part of the circuit has an oscillation waveform as shown in FIGS. Appears.

[0031] Figure 4 (1) is the base potential _{V 1} of the transistor TR ₁ of the object detection circuit 5, FIG. 4 (2) of the base potential _{V 2} of the transistor TR ₆ of the radio wave detection circuit unit 7, FIG. 4 ( 3) the collector potential _{V 3} of the transistor TR _6,
Each is shown.

FIG. 2A shows the output V _OUT-1 of the object detection circuit 5 during the oscillation operation, and FIG. 2B shows the output V _OUT-3 and V _OUT-4 of the integration / comparison circuit 3 and the output circuit 4. As shown in FIGS. 2 (3) and (4), respectively. The output V _OUT-2 ′ of the radio wave detection circuit ₇ has a waveform as shown in FIG. 4D because the transistor TR ₇ is in the ON state. The output V of this radio wave detection circuit 7
_OUT-2 'is input to a comparator (not shown) and compared with a predetermined reference value TH.
An output _VOUT-2 having the voltage waveform shown in (2) is generated.

Next, when the metal body approaches the oscillation coil L,
The oscillation circuit 2 stops the oscillation operation,
The voltage has an oscillation waveform as shown in FIGS.
Disappear. As a result, the output V of the integration / comparison circuit 3
_OUT-3Falls as shown in FIG.
Output V of wave detection circuit 7_OUT-2′ Is a transistor
TR ₇Keeps the ON state, as shown in FIG.
No change.

[0034] Now, when the radio waves arrived enters into the oscillation circuit 2 based on the oscillation coil L, the radio wave in FIG. 5, as indicated by a broken line, and reaches through internal capacitance 18 of the transistor TR ₁ to the base of the transistor TR ₁ . Therefore potential drops across the internal volume 18, the base of the transistor TR ₁ - no longer applied a sufficient voltage V _BE1 is between the emitters, it shifts the transistors TR ₁ to cut-off state.
As a result, the base potentials V ₁ and V ₂ of the transistors TR ₁ and TR ₆ decrease according to the strength of the radio wave as shown in FIGS.
_OUT-1 becomes as shown in FIG. 2A, and the output V _OUT-3 of the integration / comparison circuit 3 rises.

However, since the operating point of the transistor TR ₆ of the radio wave detecting circuit section 7 is set closer to the cut-off region than the transistor TR ₁ of the object detecting circuit section 5, before the transistor TR ₁ is turned off. first, so that the direction of the transistor TR ₆ is shifted to the cutoff state. Therefore, smaller collector current _{I C6} of the transistor TR _6, the potential _{V 3} of the collector is pushed as shown in FIG. 4 (3). As a result, the base of the transistor TR ₇ - transistor TR ₇ by emitter voltage _{V BE7} is reduced is turned off, the output V of the radio wave detection circuit section 7
_OUT-2 'falls to almost zero level as shown in FIG. As a result, the output V _OUT-2 ′ falls below the reference value TH of the comparator,
As shown in FIG. 2B, the output _VOUT-2 rises, and the inhibition signal K is generated.

Thus, the output circuit 4 regulates the passage of the output _VOUT-3 of the integration / comparison circuit 3 which has risen due to the arrival of the radio wave by the prohibition signal K. In the above embodiment, the Hartley type is used as the oscillation circuit 2. However, the present invention is not limited to this, and a Colpitts type as shown in FIG. 8 can also be used.

The oscillation circuit 2 shown in FIG. ₁ includes an LC resonance circuit 6 including an oscillation coil L and two capacitors C ₁ and C _{2. The} LC resonance circuit 6 is provided for the transistors TR ₈ and TR ₉ . 6 and the resistors R _{6 to} R ₈ to form the object detection circuit unit 5 and the transistor TR _9.
A transistor TR ₁₀ is connected to a base of the transistor TR ₁₀ via a resistor R ₉ , and further, resistors R ₁₀ , R ₁₁ and a transistor TR ₁₁ are connected to the transistor TR ₁₀ ,
A radio wave detection circuit section 7 is formed. The oscillation circuit 2 in FIG. 8 also performs the same object detection and radio wave detection as described above, and a description thereof will be omitted.

[0038]

According to the present invention , it is included in an electronic circuit.
The transistor is diode-connected and has one terminal connected to the ground potential of the electronic circuit and the other terminal connected to the power supply potential of the electronic circuit.
Since the voltage detector detects the arrival of the radio wave by detecting a decrease in the voltage between the terminals of the transistor, the malfunction of the electronic circuit due to the radio wave can be prevented. Claim
According to the second aspect, the voltage detector detects the arrival of the radio wave.
The output is stopped when the electronic circuit is
Output can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a detection circuit unit of a pachinko ball sensor to which the present invention is applied.

FIG. 2 is a time chart illustrating a circuit operation of a detection circuit unit in FIG. 1;

FIG. 3 is an electric circuit diagram showing a specific example of an oscillation circuit.

FIG. 4 is a time chart illustrating a circuit operation of the oscillation circuit of FIG. 3;

FIG. 5 is an electric circuit diagram showing a path of a radio wave entering an oscillation circuit.

FIG. 6 is an explanatory diagram showing voltage waveforms at various parts of the oscillation circuit.

FIG. 7 is an explanatory diagram illustrating voltage waveforms at various parts of the oscillation circuit.

FIG. 8 is an electric circuit diagram showing another embodiment of the oscillation circuit.

FIG. 9 is a perspective view showing the appearance of the pachinko ball sensor.

FIG. 10 is an explanatory diagram showing the principle of a proximity switch.

FIG. 11 is an explanatory diagram illustrating the principle of a proximity switch.

FIG. 12 is an electric circuit diagram showing an oscillation circuit used for a conventional proximity switch.

FIG. 13 is an explanatory diagram showing a state of approaching / separating a metal body with respect to a proximity switch and a state of arrival of a radio wave.

FIG. 14 is an explanatory diagram illustrating an output waveform of a proximity switch.

FIG. 15 is an electric circuit diagram showing another oscillation circuit used for a conventional proximity switch.

[Explanation of symbols]

1 detection circuit section 5 the object detection circuit 7 Telecommunications detecting circuit TR _1, TR ₈ diode connected transistor

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References November 30, 1974 Ohmsha, Ltd. “Electronic Engineering Pocket Book 3rd Edition” pp. 7-67 May 10, 1986, 1st Edition 1st publishing, Tokyo Denki University Press, “High Frequency, Oscillation, Modulation, Demodulation”-Jr. FET OP Amplifier, Kentaro Kikuchi, pp. 184-185

Claims (2)

(57) [Claims] A transistor and an end of the transistor
An electronic device comprising: a voltage detection unit that detects a decrease in a child voltage.
A circuit, the transistor is on the side of the contact <br/> ground potential of the diode-connected and a diode-connected one terminal of an electronic circuit, to the side of the other terminal connected to the power supply potential of the electronic circuit, respectively connected being, the voltage detecting unit, by detecting a drop in terminal voltage of the transistor, radio detection function electronic times which is adapted to detect the arrival of the waves
Road . 2. The electronic circuit according to claim 1, wherein the electronic circuit has an output circuit.
The voltage detector sends a signal to the output circuit when it detects the arrival of radio waves.
A prohibition signal is transmitted, and the output circuit receives the prohibition signal.
2. The output device according to claim 1, wherein the output is stopped when the power is turned off.
Electronic circuit with radio wave detection function.