JPS5883286A - Ultrasonic switch - Google Patents

Abstract

PURPOSE:To transmit a driving signal, a receiving signal, and power supply through one line without mutual interference, by transmitting the receiving signal of an ultrasonic wave receiving oscillator, which is provided in an ultrasonic sensor part, to an ultrasonic controlling part through the transmission line of the driving signal after amplifying this receiving signal. CONSTITUTION:When the signal is L-level by an ultrasonic transmission signal generating circuit 1, a transistor TR 3 is turned off, and the voltage between the emitter of a TR 5 and the earth becomes Vcc, and this voltage Vcc charges a capacitor 25 through a diode 19 and a resistance 24 and is supplied as the power source of an amplifier 22. When the ultrasonic transmission signal generating circuit 1 becomes the oscillation state, signals outputted by TRs 5 and 7 pass through a connection cord 11 and diodes 16 and 17, and the driving dignal is applied to an ultrasonic oscillator 20 for transmission to send ultrasonic waves for a certain time. Reflected waves are converted to an electric signal by the ultrasonic oscillator 23 for reception, and the signal amplified by the amplifier 22 is inputted to an ultrasonic receiving signal processing circuit 14 and is processed.

Description

[Detailed Description of the Invention] The present invention relates to an improvement in an ultrasonic switch in which an ultrasonic sensor section and an ultrasonic control section are independent, and in particular, it simplifies the connection between the ultrasonic sensor section and the ultrasonic control section. This invention relates to ultrasonic switches.

Conventionally, in this type of ultrasonic switch, in order to increase the wind ratio, an amplifier was provided in the ultrasonic sensor section to amplify the ultrasonic reception signal and then send it to the ultrasonic control section. However, with conventional ultrasonic switches, there is a cord that connects the ultrasonic sensor and the ultrasonic controller.

A drive signal transmission cord that is shared by the power supply for the amplifier installed in the ultrasonic sensor section and the signal that sends the ultrasonic waves from the ultrasonic transducer, and the reception of the ultrasonic waves amplified by the amplifier in the ultrasonic sensor section. Eight cords were required: a cord for sending signals to the ultrasonic control section, and a cord for connecting the ground between the ultrasonic sensor section and the ultrasonic control section. Therefore, there are many connection points,
The disadvantage was that the cost of cords was high.

The present invention has been made in view of this point, and provides an ultrasonic switch that simplifies the connection between an ultrasonic sensor section and an ultrasonic control section.

Hereinafter, the present invention will be explained in detail with reference to the drawings showing embodiments.

The drawing is an electrical circuit diagram of an ultrasonic switch according to the present invention.

In the drawing, reference numeral 1 denotes an ultrasonic transmission signal generation circuit, which is connected to an emitter resistor 4 through a resistor 2 to the base and δ base of a transistor 8. The collector of the transistor 3 is connected to the base of the transistor 5, a resistor 6 for supplying a base current, and a resistor 8 connected to the base of the transistor 7. The emitter of the transistor 5 whose collector is connected to the DC power supply Vcc and the emitter of the transistor 7 whose collector is connected to ground are the connection cords that connect the ultrasonic sensor section 9 and the ultrasonic control section 10. 11 and a resistor 12. This resistor 12 is connected to an ultrasonic reception signal processing circuit 1 that determines the presence or absence of an object from the reception signal via a DC cut capacitor 13.
Connected to 4.

The ground of the ultrasonic controller IO composed of the above components (excluding the connection cord 11) is connected to the ground of the ultrasonic sensor section 9 through the connection cord 15.

The connection cord 11 is connected to diodes 16 and 17, a resistor 18, and a diode 19 which are connected in parallel in the opposite direction in the super wave sensor section 9, and the diode 16
．． A transmitting ultrasonic transducer 20 is connected between 17 and ground.

Further, a DC cut capacitor 21 connected in series with the resistor 18 is connected to the output side of an amplifier 22, and a reception ultrasonic transducer 23 is connected to the input side of the amplifier 22. Further, a resistor 24 is connected in series with the diode 19.
．． A ripple removal capacitor 25 is connected, and the power supply side of the amplifier 22 is connected between the resistor 24 and the capacitor 25.

The ultrasonic sensor section 9 is composed of the above-mentioned parts.

Next, the operation of the above circuit will be explained.

In the above circuit, a signal is output by the ultrasonic transmission signal generation circuit 1. When this signal is L, transistor 3 is turned off, and when transistor 3 is turned off, the resistor 6 brings the potential to approximately Vcc, and a pace current flows through transistor 5, turning it on, but no pace current flows through transistor 7. The transistor 5 is turned off, and the potential between the emitter and the pace of the transistor 5 becomes Vcc. When the voltage between the emitter of transistor 5 and ground becomes Vcc, this Vcc is applied to diode 19. The capacitor 25 is charged through the resistor 24, and is supplied as power to the amplifier 22.

When the ultrasonic transmission signal generation circuit 1 enters the oscillation state.

The signal output by transistor 5.7 passes through connection cord 11 and is input to diode 16.17. These diodes 16 and 17 have a high impedance for low level signals such as the output of the amplifier 22, and a low impedance for high level signals such as the drive signal, and the ultrasonic waves for transmission are transmitted through these diodes 16 and 17. A drive signal is applied to the vibrator 20 to send ultrasonic waves for a certain period of time.

After transmitting ultrasonic waves for a certain period of time, the reflected waves are converted into electrical signals by the receiving ultrasonic transducer 28 and input to the amplifier 22. The signal amplified by the amplifier 22 is passed through the DC cut capacitor 21, the current limiting resistor 18, and the , and is input to the ultrasonic reception signal processing circuit 14 via the current limiting resistor 12 and DC cut capacitor 13 of the ultrasonic controller 10 through the connection cord 11 and processed.

As described above, in the present invention, an ultrasonic sensor section and an ultrasonic control section are provided independently, and a drive signal for an ultrasonic transducer drive circuit provided in the ultrasonic control section is provided to the ultrasonic sensor section. In ultrasonic switches that supply power to circuits such as amplifiers, etc.

Since the received signal of the ultrasonic receiving transducer provided in the ultrasonic sensor unit is amplified, the amplified signal is transmitted to the ultrasonic control unit through the drive signal transmission line.
1 without any interference between the drive signal, reception signal, and power supply.
Since the ultrasonic control section and the ultrasonic sensor section can be connected using two wires including the ground wire, the cost is low and the connection is simple.

[Brief explanation of drawings]

The drawing is an electrical circuit diagram of an ultrasonic switch showing an embodiment of the present invention. l: Ultrasonic transmission signal generation circuit, 8.5.7:) Transistor, 11, 15: Connection cord, 9: Ultrasonic sensor section, 1
0: Ultrasonic control unit, 20: Ultrasonic transducer for transmission, 23:
Ultrasonic transducer for reception. Agent Patent Attorney Aihiko Fukushi

Claims (1)

[Claims] 16 An ultrasonic sensor section and an ultrasonic control section are provided independently, and a drive signal of an ultrasonic transducer drive circuit provided in the ultrasonic control section is transmitted to a circuit such as an amplifier provided in the ultrasonic sensor section. The ultrasonic switch supplied as a power source is characterized in that a received signal of an ultrasonic reception transducer provided in the ultrasonic sensor section is amplified by an amplifier and then transmitted to the ultrasonic control section through the drive signal transmission line. Ultrasonic switch.