JPS6116559A - Trimming device - Google Patents

Abstract

PURPOSE:To prevent a malfunction resulting from defective connection with a proximity switch, and to improve yield on a product on the trimming work of the proximity switch by providing a signal input section connected to a signal output terminal for the proximity switch with a detecting means detecting the power consumption of said switch. CONSTITUTION:When a trimming device 1 and a proximity switch 2 are connected defectively at nodes P1, P2, a signal applied to a signal input section INP1 for the trimming device 1 is at a low level from the beginning, thus operating no trimming device 1. When they are connected defectively at a node P3, a light- emitting diode 6 for a photo-coupler 4 does not emit light, thus resulting in non- conduction of a photodiode 5. Consequently, the signal applied to the signal input section INP1 for the trimming device 1 is at the low level, thus operating no trimming device 1. Accordingly, when the trimming device 1 and the proximity switch 2 are connected defectively at either of the nodes P1, P2, P3, the trimming device 1 is not operated, thus preventing a malfunction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a trimming device for trimming a resistance for adjusting the sensitivity of a proximity switch.

<Prior art and its problems> Generally, the detection sensitivity of a proximity switch that detects the presence or absence of an object needs to be adjusted in advance depending on the situation in which the proximity switch is installed. For this reason, conventionally, as shown in FIG. 2, a trimming device t is applied and a proximity switch
The resistor R for adjusting the detection sensitivity provided in the sensor is trimmed. That is, while the detection object m is placed at a predetermined distance of 11 from the proximity switch X, the trimming device t
Connect the power output section OUT and signal input section "01% jnp2" to each input/output terminal of the proximity switch X at the connection point p1% p2
, p, respectively. Note that one signal input section 1np2 of the trimming device t is set to zero volts. The trimming device t is a proximity switch
The resistor R2 is trimmed based on a signal given from the terminal p2 to one signal input section inp through the connection point p2.

Along with this trimming, the resistance R1 value gradually increases, and as a result, as shown in FIG.
The signal of the proximity switch X applied to the signal input section inp is inverted from high level to low level. Since the value of the resistor R1 at that time corresponds to the detection sensitivity, the trimming device t
will cancel the trimming operation.

Incidentally, the connection between the trimming device t and the proximity switch is normally made by a probe board, but if there is a defect in the position adjustment of this probe board, a connection failure may occur between the two. If there is a connection failure between the trimming device t and the proximity switch
Since the signal from the proximity switch applied to p is at a low level from the beginning, it can be seen that the trimming device t does not operate and a connection failure has occurred. Therefore, in this case, there is no problem as long as the connection is reset. However, if a connection failure occurs between the trimming device t and the proximity switch x at the connection point p3, the signal input section 1 of the trimming device t
Since the level of the signal applied to np1 is initially high level, trimming will start, but even if trimming starts, proximity switch X does not operate normally, so the signal output of proximity switch It does not reverse and remains at a high level. As a result, the trimming is not completed (and the proximity switch is destroyed. The purpose of this invention is to prevent malfunctions caused by this and to improve product yield during trimming work of proximity switches.

<Configuration and Effects of the Invention> In order to achieve the above object, the present invention configures a trimming device by providing a detection means for detecting power consumption of the proximity switch in a signal input section connected to a signal output terminal of the proximity switch. ing.

Since the present invention is configured as described above, when the connection with the proximity switch is defective, this can be reliably detected. Therefore, it is possible to prevent the trimming device from malfunctioning, and this has an excellent effect of contributing to improving the product yield during the trimming work of the proximity switch.

<Description of Examples> Hereinafter, the present invention will be described in detail based on examples shown in the drawings.

FIG. 1 is a configuration diagram including a trimming device of this embodiment and a proximity switch connected thereto.

In the figure, numeral 1 is a trimming device and 2 is a proximity switch. This trimming device 1 is equipped with a device main body 3, and this device main body 3 has one power output section out and two
Two signal input sections inp, , in I)2 are provided. Then, the power output section out is set to 12V,
Furthermore, one of the two signal input sections 1np2 is set to zero volts. Reference numeral 4 denotes a detection means for detecting the power consumption of the proximity switch 2. In this example, the detection means 4 is composed of a photocoupler consisting of a phototransistor 5 and a light emitting diode 6. ,,1np2 and the input/output terminal of the proximity switch 2.

Furthermore, pLp2 and p3 are connection points between the trimming device 1 and the proximity switch 2, respectively. 8 is an oscillation circuit equipped with a detection coil L, 9 is a constant current circuit, and 10 is a proximity switch 2
This is a detection object placed a predetermined distance 1 from the detection coil L of. R1 is a resistance for adjusting detection sensitivity, Dl is a diode, and Ql is a signal output transistor.

In such a configuration, when the rimming device 1 and the proximity switch 2 are connected normally, power is supplied from the power output section OUT of the trimming device N1 to the proximity switch 2 via the connection point p1, The power consumed by the proximity switch 2 is detected by the detector 4 via the connection point p. Further, the trimming device 1 is connected to one signal input section inp from the proximity switch 2 via the connection point p2.
, trims the resistor R1 based on the signal applied to the resistor R1. At this time, the photocoupler 4 is in a conductive state, and
When the value of the resistor R2 is still small at the start of trimming, the signal output transistor Q is cut off. Therefore, the signal from the proximity switch 2 applied to the signal input inp of the trimming device 1 is at a high level. As the resistance R1 value gradually increases with trimming,
A signal output appears at the base of the signal output transistor Q1, and as a result, the signal output transistor Q1 is turned on and enters the oil conducting state. As a result, the trimming device 1
Signal input section! The signal from the proximity switch 2 applied to np+ is inverted from high level to low level. This level reversal causes the trimming device to stop the trimming operation.

The connection point between trimming device 1 and proximity switch 2 is +11%
If a connection failure occurs at p2, the signal applied to the signal input section inp of the trimming device 1 will be at a low level 1) from the beginning, so the trimming device 1 will not operate. Furthermore, if there is a connection failure at the connection point p3, the light emitting diode 6 of the photocoupler 4 will not emit light to the outside, and therefore the photodiode 5 will be non-conductive. Therefore, the signal applied to the signal input section 1npl of the trimming device 1 is at a low level, and 1) the trimming device 1 does not operate.

Like this, trimming device 1 and close, 3 & switch 2
If a connection failure occurs at any of the connection points p1, p2, and p3, the trimming device 1 will not operate, thereby preventing malfunction.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram including a trimming device according to an embodiment of the present invention and a proximity switch connected thereto, FIG. 2 is a configuration diagram including a trimming device of a conventional example and a proximity switch connected thereto, and FIG. The figure is an explanatory diagram of the signal level applied to the signal input section of the trimming device. 1... Trimming device, 2... Proximity switch, 4...
...Detection means (7O) coupler).

Claims (2)

[Claims] (1) A trimming device for trimming a resistance for adjusting the sensitivity of a proximity switch, wherein a detection means for detecting power consumption of the proximity switch is provided in a signal input section connected to a signal output terminal of the proximity switch. A trimming device featuring: (2) The trimming device according to claim 1, wherein the detection means is a photocoupler.