JPS5931980B2 - Contact inspection and polarity determination device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a contact inspection and polarity discrimination device used in a marking machine that makes a polarity mark on a diode.

Manufactured diodes are marked with polarity using a marking machine, during which the diode is tested for polarity and rectification, thereby marking the correct polarity.

By the way, as a prerequisite for this test, it has become necessary to inspect the contact between the diode input terminal of the device and the diode lead wire. Fig. 1 is a circuit diagram showing an example of a conventional device, where E3, E2, and E3 are DC power supplies, 1-a, 2-
3-a to a, 6-a to 6-a are 1 to the relay, respectively.
2, 3... and 6 normally open contacts (however, relays 1, 3, and 5 are not shown), KT-b has 1 normally closed contact (not shown) in relay, 1 is the diode under test.

With contact KT-b closed, connect contacts 11a and 3.
-a, when 5-a is closed sequentially, contact point p, q (7) If the contact is good, relay 2 operates; if contact point s is good, relay 6 operates; diode under test If 1 is in the correct polarity as shown by the solid line in the figure, 4 is activated in the relay and it is determined that it is normal.

At this time, if relays 2 and 6 are activated and relays 4 and 4 are not activated, the contact at each contact point is good, but either the polarity of diode 1 is reversed or it is disconnected.

Even if 4 does not work on relay, 2 or 6 on relay
If one of the contact points does not work, check the contact at the contact point on the non-working side, eliminate this contact failure, and then perform the test described above. However, this device uses relay contacts to open and close, and if poor contact of these contacts becomes a problem, the reliability of the test will deteriorate, and it is difficult to expect the test speed to improve.

Fig. 2 is a circuit diagram showing another example of the conventional device, where e is an AC power supply, T1 is an isolation transformer, Rl and R2 are resistors, E4,
E5 is a reference voltage source, 2 and 3 are comparators, and 4 and 5 are flip-flop circuits.An AC voltage is applied to diode 1 under test through resistors R, R2,
A current flows through the resistor R2 in one direction depending on the polarity of the resistor R2.

The voltage across resistor R2 due to this current is compared with reference voltages E4 and E by comparators 2 and 3, respectively, and the flip
Either one of flop circuits 4 and 5 is set. In the illustrated configuration, when the diode 1 has the polarity indicated by the solid line, the comparator 2 produces an output "I", which sets the flip-flop circuit 4 and outputs the judgment output signal "2". On the other hand, when the diode 1 has the polarity indicated by the broken line, the output port of the comparator 3 sets the flip-flop circuit 5 and outputs the judgment output signal H. If diode 1 is disconnected, no output signal will be output to either of them. This device is non-contact and has the advantage of being able to perform measurements at high speed, but the contact between the diode input terminal of this measurement device and the diode lead wire has not been inspected. Therefore, it is impossible to distinguish between the aforementioned contact failure and diode disconnection.

Furthermore, since a commercial AC power supply is used as the power supply for the first test,
Malfunctions may occur due to noise from the power supply circuit.
This invention was developed in view of the above points, and is a contactless, high-speed and stable method for conducting lead wire contact inspection and determining the polarity of the object to be measured. The purpose of this paper is to provide a circuit that does this. Figure 3a is a circuit diagram showing an embodiment of the principle of this invention.
2 is a PNP transistor, Q3 and Q4 are NPN transistors, R3 and R4 are current limiting resistors, R5 is a current detecting resistor, and E6 is a stabilized DC power supply. They are respectively connected to input terminals provided between the resistor R3 and the collector of the transistor Q3 and between the resistor R4 and the collector of the transistor Q4.

FIG. 3b is a waveform diagram of each part for explaining the operation of the circuit of FIG. , waveform N is the detected output voltage across the resistor R5.

During period T1, transistors Q1 and Q3 are conductive (transistors Q2 and Q4 are non-conductive), and when there is good contact between the lead wire on the cathode side of diode 1 and the input terminal shown by the solid line, E6→Q1→R3 →Q3→R5→E6 A current flows through the closed circuit, and a voltage appears across the resistor R5.
If there is poor contact between the lead wire and the input terminal, no voltage will appear across the resistor R5. In this manner, a contact test to the input terminal on the cathode side of the diode 1 is performed during the period T1. During period T2, transistors Q2 and Q
4 is conductive (transistors Ql and Q3 are non-conductive), and a contact test is performed between the lead wire on the anode side of diode 1 and the input terminal.

Next, during period T3}, transistor QlQ4 becomes conductive (transistors Q2 and Q3 are non-conductive), and E6→Q1→
A closed circuit of R3→diode 1→Q4→R,→E6 is formed, and no current flows when diode 1 has the polarity shown by the solid line, but current flows when the diode 1 has the polarity shown by the broken line.

Further, during period T4, transistors Q2 and 9 are conductive (transistors Ql and Q4 are non-conductive), and when diode 1 has the polarity shown by the solid line, current flows through resistor R5.
No current flows when the polarity is indicated by the broken line.

}, if there is a disconnection in diode 1, even if the result of the contact test in periods T, T2 is good, the period T3, T2
4, no current flows through the resistor R5.

On the other hand, if there is a short circuit in the diode 1, current flows through the resistor R5 during both periods T3 and T4. The above can be summarized as shown in the table below. The outputs of the output correspond to outputs A, B, C, D, E} and F shown in FIG. 3B in order from the top.

Fig. 4a is a circuit diagram showing another embodiment of the present invention in which a peripheral auxiliary circuit is added.
This is the same as the embodiment shown in .

Transistors Q5 to Q8 and resistors R6 to Rl5 constitute a drive auxiliary circuit, 6 is a comparator that compares the output voltage across the current detection resistor R5 with reference voltage E7, 7 is a shift register, and 8 and 9 are 0R gates. , 10 and 11 are NOR gates, 12 is a clock pulse generator, and 13 is a shift register. FIG. 4b is a waveform diagram of each part for explaining the operation of this embodiment. When a start signal is applied, the clock pulse generator 12 receives this and generates a clock pulse and a strobe pulse.

The shift register 7 receives the start signal and this clock pulse and generates delayed outputs in sequence. These outputs are combined by 0R gates 8 and 9 and NOR gates 10 and 11 to obtain test section 1 drive signals R, S, T, and N. As a result, the bases of the transistors Q1 to Q4, which constitute the main part using the transistors Q5 to Q8 and the resistors R6 to Rl5, can be set as shown in FIG.
It can be easily understood from the circuit configuration that the drive voltage waveforms shown in Figure 1 can be obtained with the following values. In this way, the lead wire contact inspection and polarity determination of the diode 1, which is the object under test, are performed sequentially. The energization signal N generated across the current detection resistor R5 and the reference voltage E7 corresponding to the reference current are detected by the comparator 6. When the comparison outputs are shifted into the shift register 13 by the above-mentioned straw flux, each output contains information as shown in the waveforms C, I, NO, and O.

Therefore, it is easy to understand that these signals after the test correspond to the outputs at timings T4, T3, T2, and T in FIG. 3b. The test object 1 can be classified into poor contact, forward direction, reverse direction, disconnection, and short circuit. In each of the above embodiments, whether or not a predetermined current has been applied is only determined based on the comparison output of the comparator 6, but the magnitude of the forward voltage of the test object 1 may also be involved in the determination. .

FIG. 5 is a circuit diagram showing still another embodiment of the present invention having such a function, in which 14 to 16 are operational amplifiers, and 17 are operational amplifiers.
is a comparator, and 18 is an AND circuit. The forward voltage of the test object 1 is detected as a signal by a voltage difference detection circuit composed of an operational amplifier 14 and resistors R16 to R19. Since this voltage takes either positive or negative values, the operational amplifier 15
, 16, diodes D, , D2, and resistors R2O-R
The absolute value M is detected by the absolute value circuit constituted by 24, and compared with the reference voltage E8 by the comparator 17 to obtain a forward voltage magnitude determination signal K. If the energization determination signal 7 obtained by combining this signal A and the above-mentioned signal A in an AND circuit 18 is used in place of the current detection signal A, the magnitude of the forward voltage can be involved in this test. Although the present invention has been described above for use in a diode marking machine, it can also be applied to a diode testing machine, etc., and the test object is not limited to diodes, but can be used for directional elements in general.

As detailed above, in this invention, one pole of the test object is brought into contact with the first contact terminal and the second contact terminal, the other pole is brought into contact with the third contact terminal and the fourth contact terminal, and the DC power supply The first } and second non-contact switching elements are capable of opening and closing energization from the positive electrode to the first } and third contactors, respectively, and the energization from the second and fourth contactors to the negative electrode of the DC power source. Since it is equipped with third and fourth non-contact switching elements that can be opened and closed, respectively, and a resistor that limits the current supplied from the DC power supply,
By combining the opening and closing of the first to fourth non-contact switching elements, it is not only possible to inspect the contact of the contact terminals and determine the polarity of the test object at high speed and stability. It is also possible to check for loss of current directionality due to disconnection or short circuit.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an example of a conventional device, Fig. 2 is a circuit diagram showing another example of the conventional device, Fig. 3a is a circuit diagram showing an embodiment of the principle of the present invention, Fig. 3b 3A is a waveform diagram of various parts for explaining the operation of the circuit of FIG. 3a, FIG.
Fig. b is a waveform diagram of various parts for explaining the operation of the circuit of Fig. 4a, and Fig. 5 is a circuit diagram showing still another embodiment of the present invention. E6 is a DC power supply, Q
l, Q2, Q3} and Q4 are the first, second, and third, respectively.
} and the fourth non-contact switching element, R3 and R4 are current limiting resistors.

Claims (1)

[Claims] 1. First and second contact terminals that are in contact with one pole of a test object having current directionality, and third and fourth contact terminals that are in contact with the other pole of the test object. , first and second non-contact switching elements capable of switching on and off electricity from the positive electrode of the DC power source to the first and third contact terminals, respectively; from the second and fourth contact terminals to the negative electrode of the DC power source; third and fourth non-contact switching elements capable of respectively switching on and off energization;
and current value detection means for detecting the current supplied from the DC power supply, the first and third non-contact switching elements being in a closed state and the second and fourth non-contact switching elements being in an open state. A first case, a second case in which the first and third non-contact switching elements are in an open state, and a second case in which the second and fourth non-contact switching elements are in a closed state, and a second case in which the above-mentioned first and fourth non-contact switching elements are in a closed state. A third case in which the non-contact switching element is in a closed state and the second and third non-contact switching elements are in an open state, and a third case in which the second and third non-contact switching elements are in a closed state and the first and third non-contact switching elements are in a closed state. The quality of the contact of each of the contact terminals and the polarity of the test object are determined from the current value detected by the current value detection means in the fourth case in which the non-contact switching element of No. 4 is in an open state. Features a contact inspection and polarity determination device. 2. The contact inspection and polarity discrimination device according to claim 1, wherein transistors are used for the first, second, third, and fourth non-contact switching elements.