JPH0989974A - Detecting device of connector falling-off and power source abnormality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce device cost and improve reliability by providing such a structure that a host device can detect the presence of connector falling-off and abnormality of power source voltage in a slave device connected to the host device by connector connection with a small using number of connector pins. SOLUTION: The phototransistor 5T of a photocoupler 5 is inserted in series to a connector falling-off detecting signal line 1 for connecting the pins P1, P2 of a connector CN2 within a slave device 02. When a power source voltage 2 is present, a current is carried to the photodiode 5D of the photocoupler 5 through a resistor 3 to continue the phototransistor 5T. Thus, if the power source voltage 2 is present, and the connector pins P1, P2 are inserted to a connector CN1 by the connection of the connectors CN1, CN2, the detecting circuit 9 of a host device 01 can detect a grounding potential 8 in the route of the pin P1 → the signal line 1 → the phototransistor 5T → the pin P2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device in which a host device detects a connector dropout and a power supply abnormality as an abnormality of a lower device connected to a host device through a connector, and more particularly to a connector used for detecting this abnormality. The present invention relates to a connector dropout and power supply abnormality detection device capable of reducing the number of pins.

[0002] In the drawings, the same reference numerals indicate the same or corresponding parts.

[0003]

2. Description of the Related Art FIG. 3 shows an example of a general configuration of an abnormality detecting device of this type. In the figure, 01 is a host device, 02 is a lower device connected to the host device 01 by a cable, C
N1 and CN2 are used for this connection, respectively, host device 0
A connector with a large number of pins on the 1 side and the lower device 02 side, P
1 to P4 are connector C from the connector CN2 side in this example.
It is a connector pin inserted on the N1 side.

In the lower device 02, 1 is a connector drop detection signal line connecting between the pins P1 and P2 of the connector CN2, 2 is a power supply voltage of the lower device, 5 is a photocoupler as a voltage detecting element, and 3 is a power supply voltage. A resistor that determines the current flowing through the photodiode 5D of the photocoupler 5 by
Reference numeral 4 denotes a voltage abnormality detection signal line that passes through the phototransistor 5T of the photocoupler 5 and connects between the pins P3 and P4 of the connector CN2.

In the host device 01, 6 is a connector abnormality detecting circuit connected to the pin P1 inserted in the connector CN1, 7 is a power abnormality detecting circuit connected to the pin P3 similarly inserted in the connector CN1, and 8 Is connector C
This is the ground potential connected to the pins P2 and P4 inserted in N1. In the circuit of FIG. 3, when the connectors CN1 and CN2 are connected, the connector abnormality detection circuit 6 causes the connector pin P1.
→ Connector disconnection detection signal line 1 → The ground potential 8 can be detected through the path of the connector pin P2, and it can be determined whether or not the connector is disconnected, depending on whether or not the ground potential 8 is detected.

Similarly, at this time, in the power supply abnormality detection circuit 7, if the power supply voltage 2 on the lower device 02 side exists, a current flows through the photodiode 5D of the photocoupler 5 through the resistor 3 and the phototransistor 5T becomes conductive. Connector pin P
3 → power supply abnormality detection signal line 4 → phototransistor 5T →
The ground potential 8 can be detected through the path of the connector pin P4, and the presence or absence of the detection of the ground potential 8 can determine the presence or absence of the power supply voltage 2, respectively.

[0007]

However, the circuit of FIG. 3 requires wiring connection of four connector pins and two detection circuits in order to detect connector disconnection and power failure, which is an extra connector pin. However, there is a problem in that the number of parts such as the detection circuit is large and the reliability is low.

[0008] Therefore, an object of the present invention is to provide a device for detecting connector disconnection and power supply abnormality that can solve this problem.

[0009]

In order to solve the above-mentioned problems, in the detection device according to claim 1, the host device (0, 0) is connected via connectors (CN1, CN2) having more than two pins.
The lower device (02) connected to 1) is inserted in series with the signal line (connector disconnection detection signal line 1) connecting between the predetermined two pins (P1, P2) of this connector and the signal line itself. And a voltage detection element that conducts in the presence of a power source (power supply voltage 2), and the host device includes means (detection circuit 9) for detecting the presence or absence of conduction between two predetermined pins of the connector. .

According to a second aspect of the detection device of the present invention,
In the detection device described in (1), the lower device includes a switch (SW1) that switches whether to insert the voltage detection element in series with the signal line. Moreover, in the detection device of claim 3, in the device of claim 1 or 2,
The voltage detecting element is a photocoupler (5).

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 is a circuit diagram showing a configuration as a first embodiment of the present invention. 3, the phototransistor 5T of the photocoupler 5 as a voltage detection element is connected in series with the connector dropout detection signal line 1 in contrast to FIG. Reference numeral 9 is a detection circuit for detecting connector dropout and power failure connected to the connector pin P1 inserted into the connector CN1 of the host device 01.

In FIG. 1, when the connectors CN1 and CN2 are connected and the power supply voltage 2 is present, a current flows through the photodiode 5D of the photocoupler 5 and the phototransistor 5T becomes conductive. Therefore, the detection circuit 9 is connected to the connector pin P1.
→ Connector drop detection signal line 1 → Phototransistor 5T
→ The ground potential 8 can be detected through the path of the connector pin P2.

That is, the detection circuit 9 detects "there is no connector drop and the power supply voltage 2 exists" or "there is a connector drop or power supply" depending on whether or not the ground potential 8 is detected via the connector pin P1. It is possible to determine whether “voltage 2 does not exist”. (Embodiment 2) FIG. 2 is a circuit diagram showing a configuration as a second embodiment of the present invention. In FIG. 1, a switch SW1 for switching whether to insert the phototransistor 5T of the photocoupler 5 in series into the connector drop detection signal line 1 is added to FIG.

In FIG. 2, when the switch SW1 is set to the side "a", the phototransistor 5T is connected in series to the connector drop detection signal line 1, and the detection circuit 9 "connects the connectors CN1 and CN2" as in FIG. , And lower device 0
It is possible to determine whether or not the power supply voltage 2 of 2 exists ”. Further, when the switch SW1 is set to the b side, the detection circuit 9 is similar to the connector abnormality detection circuit 6 of FIG.
If 2 is connected, the circuit from the detection circuit 9 to the ground potential 8 constitutes a closed circuit, and connector dropout and half insertion can be detected.

[0015]

According to the first aspect of the present invention, the voltage detection is conducted in series with the connector drop detection signal line connecting the two pins of the connector to which the lower device is connected to the upper device, in accordance with the power supply voltage of the lower device. Since the elements are provided in series, the upper device detects whether or not there is continuity between the two pins of this connector to determine whether "there is no disconnection of the connector and the power supply of the lower device exists". It is possible to make a determination, solve the problems of low reliability in the conventional abnormality detection circuit, the large number of wiring connections, and the need for multiple detection circuits to reduce the cost and improve the reliability of the device. You can

Further, depending on the apparatus, there is a case where only the abnormality detection of the presence or absence of the connector drop may be performed functionally and physically.
According to the invention of claim 2, since the switch for switching whether or not the voltage detection element is inserted in the connector dropout detection signal line in series is added as described above, only the presence or absence of the connector dropout in the same device It is also possible to serve both as a device for detecting the presence of a connector and a device for detecting the presence or absence of "no connector drop and no power supply abnormality".

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a configuration as a first embodiment of the present invention;

FIG. 2 is a circuit diagram showing a configuration as a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing a conventional general configuration.

[Explanation of symbols]

 01 Upper device 02 Lower device CN1 Upper device side connector CN2 Lower device side connector P1, P2 Connector pin 1 Connector dropout detection signal line 2 Power supply voltage 3 Resistor 5 Photocoupler (voltage detection element) 5D Photodiode 5T Phototransistor 8 Ground potential 9 Detection circuit SW1 switch

Claims (3)

[Claims] 1. A lower device connected to a higher device via a connector having more than two pins, and a signal line connecting between two predetermined pins of this connector and a signal line inserted in series to this signal line. And a voltage detecting element that conducts when a power source is present, and the upper device has means for detecting the presence or absence of continuity between two predetermined pins of the connector. . 2. The device according to claim 1, further comprising a switch that switches whether or not the lower device inserts the voltage detection element in series with the signal line. Detection device. 3. The device according to claim 1, wherein the voltage detection element is a photocoupler, and the connector is disconnected and the power supply is abnormal.