JPH02287268A - Apparatus for checking printed circuit board - Google Patents

Abstract

PURPOSE:To prevent the accident such as breakdown of an IC in a post-process by providing a voltage sensor having an output contact detecting charged volt age to be turned ON/OFF corresponding to a set voltage value. CONSTITUTION:When a power supply switch 5 is turned OFF and a switch 7 is changed over from a contact (a) to a contact (b), charged voltage is detected by the first and second voltage sensors 12, 13. When the charged voltage is equal to or more than the first set value, detection output is obtained from the sensor 12 and the first contact 12a is turned ON and, therefore, a contact 14c is turned ON. If a lever 3 is operated in this state, a limit switch 16 is turned ON and the power supply voltage of a power supply line 6 is supplied to an annnciator 17 to operate said annunciator 17. As a result, a display lamp 19 lights flickeringly and a buzzer 20 emits alarm sound. When the charge voltage drops to reach the second set value or less, the detection output is obtained from the sensor 13 and the second contact 13a is turned ON and the contact 14c becomes an OFF-state and the annunciator 17 is not operated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printed circuit board checking device for checking the operation of a printed circuit board on which circuit components are mounted.

[Conventional technology]

Fig. 3 is a plan view showing a conventional printed circuit board checking device. This is for fixing the printed circuit board and bringing the contact pin 2 into contact with the land of the printed circuit board. 4 is a guide bin for attaching a printed circuit board, and 5 is a power switch.

FIG. 4 is a circuit diagram showing the circuit configuration for discharging the circuit on the printed circuit board, 6 is a power line, and when the power switch 50 is turned on, the power supply circuit installed on the base 1 is connected to the power supply line. supply. Reference numeral 7 designates a discharging switch that is interlocked with the power switch 5, and its contacts are connected to a circuit using a capacitor or the like that is charged with electric charge on a printed circuit board. 8 is a discharge resistor connected to the movable contact (output side) of the switch.

FIG. 5 shows the printed circuit board 9 to be checked.
Various circuit components 10 are mounted on the mounting surface, and mounting holes 11 are provided.

Next, the operation will be explained.

First, the guide pins 4 are inserted into the mounting holes 11 of the printed circuit board 9, and the printed circuit board 9 is mounted on the base 1 with the mounting surface facing upward. Next, when the lever 3 is rotated approximately 90 degrees, the printed circuit board 9 is fixed, and a predetermined contact pin 2 is pressed against a predetermined land of the wiring pattern on the back side, thereby forming a predetermined check circuit. Ru.

Next, the power switch 5 is turned on to apply a predetermined voltage to the check circuit. meter in this condition.

Check the magnitude of voltage, current, etc. at a predetermined location while looking at a monitor, etc., and determine whether it is normal or abnormal. Note that at this time, the switch 7 is closed to the contact a side.

When the check is completed and the power switch 5 is turned off, the switch 7 is switched to the contact side in conjunction with this. As a result, the resistor 8 is connected to form a discharge circuit, and the electric charge stored in a circuit using a capacitor or the like on the printed circuit board 9 is discharged through this discharge circuit.

In television receivers, two-display monitors, etc., two to six such printed circuit boards 9 are usually used.
This is checked in the above manner one by one. After each 5° check, turn off the power switch 5, perform the above discharge, operate the lever 3 to take out the printed circuit board 9, and proceed to the - process. ends.

[Problem to be solved by the invention]

Since the conventional printed circuit board checking device is configured as described above, if the lever 3 is operated immediately without waiting after the power switch 5 is turned off, the discharge will not be sufficient and the printed circuit board will be damaged. There is a problem in that the charged voltage flows to the next process, and the charged voltage destroys ICs and the like in subsequent processes.

This invention was made to solve the above-mentioned problems, and its purpose is to provide a printed circuit board checking device that displays an alarm when the discharge circuit is released before the charged voltage is sufficiently discharged. shall be.

[Means to solve the problem]

A printed circuit board checking device according to the present invention includes a voltage sensor having an output contact that detects a charge voltage and turns on and off according to a set voltage value, and detects the state of the charge voltage according to the state of the output contact. is displayed.

[For production]

The printed circuit board checking device according to the present invention can know when the charging voltage is high after the check is completed and the power switch is turned off.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In FIGS. 3 and 2, the same parts as in FIGS. 3 and 4 are given the same reference numerals, and their explanations will be omitted.

In FIGS. 1 and 2, reference numeral 12 denotes a first voltage sensor, which is connected in parallel with the resistor 8 to the output side of the switch 7, and provides a detection output when the charge voltage is equal to or higher than a first set value. A second voltage sensor 13 is connected in parallel with the resistor 8 and the first sensor 12, and provides a detection output when the charge voltage is below a second set value. 12
a is the first voltage sensor that is turned on by the detection output of the first voltage sensor 12;
The contact 13a is the second contact that is turned on by the detection output of the second voltage sensor 13, and the latch relay 14a is the first contact.
14b is a trip coil connected to the second contact 13a, 14C is turned on and mechanically held when the close coil 14a is excited, and the trip coil 14b is energized. This is the contact point of the latch relay 14 that turns off when the 16 is a limit switch, which connects the lever 3 to the printed circuit board 9.
When the check circuit is fixed and operated so that the above-mentioned check circuit is formed, it turns off, and the lever 3 and the printed circuit board 9 are connected to the base 1.
It turns on when it is operated in such a way that it can be removed from the battery and a flickering circuit is no longer formed. 1T is an annunciator, which is operated by turning on contact 14C and limit switch 160. 18 is a flicker relay, which is operated by the annunciator 17. 18a is a flicker contact, which is operated by the flicker relay 18. 1
Reference numeral 9 indicates an indicator light, and reference numeral 20 indicates a buzzer, each of which is operated by an annunciator 17. 21 is a display stop switch.

In addition, the annunciator 172 indicator light 19 and buzzer 20
A display device is configured by the above.

Next, the operation will be explained.

The operation check of the printed circuit board 9 is performed according to the same procedure as the conventional method described above. During this operation check, the limit switch 16 is off.

Next, when the check is completed and the power switch 5 is turned off and the switch 7 is switched from contact A to contact A, a discharge current flows through the resistor 8 and the charge voltage is applied to the first and second voltage sensors 12. , 13. When the charging voltage is equal to or higher than the first set value (for example, 50V), a detection output is obtained from the first voltage sensor 12, which turns on the first contact 12a. Therefore, the close coil 14a is excited and the contact 14C is turned on.

When the charge voltage is higher than the first set value, if the lever 3 is operated and the printed circuit board 9 is taken out or the check circuit is not formed, the limit switch 16 is turned on. As a result, the power supply voltage of the power supply line 6 is supplied to the annunciator 17 via the contact 14C and the IJ Mitswitch 16, and the annunciator 17 is operated. As a result, the flicker relay 18 operates and the flicker contact 18a flickers, causing the indicator light 19 to flicker and the buzzer 20 to emit an alarm sound.

This allows the operator to know not to take out the printed circuit board 9.

After the above-mentioned check is completed and the power switch 5 is turned off, the check circuit is formed while the printed circuit board 9 is fixed, that is, the limit switch 16 is turned off and the charge voltage is set to the first level. When the charge voltage decreases from a state where it is above the set value, that is, when the first contact 12a is on and the contact 14c is on, and becomes less than the second set value (for example, 10V), the second voltage sensor 13
The detection output is obtained from As a result, the second contact 13a
is turned on, trip coil 14b is excited, and contact 14C is turned off. Therefore, if the lever 3 is operated in this state to allow the printed circuit board 9 to be taken out, the limit switch 16 will be turned on, but since the contact 14C is turned off, the annunciator 17 will not operate. Therefore, neither the indicator light 19 nor the buzzer 20 operates. This allows the operator to know that it is okay to take out the printed circuit board 9.

〔Effect of the invention〕

As described above, according to the present invention, when the discharge circuit is released while a high charge voltage remains, a warning is given by a buzzer, a flicker of an indicator light, etc. There is no risk that the printed circuit board will flow to a later process, and there is an effect that accidents such as destruction of the RC in the later process can be prevented.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a printed circuit board checking device according to an embodiment of the present invention, FIG. 2 is a plan view of the same device, and FIG.
The figure is a plan view showing a conventional printed circuit board checking device.
FIG. 4 is a circuit diagram showing the discharge circuit of the device, and FIG. 5 is a plan view of the printed circuit board. T is a switch, 12 is a first voltage sensor, 13 is a second voltage sensor, 12a is a first contact, 13a is a second contact, 17 is an annunciator, 19 is an indicator light, and 20 is a buzzer. , the same symbols indicate the same or equivalent parts. Patent applicant: Mitsubishi Electric Corporation

Claims (1)

[Claims] A switch is provided on the output side of the switch to set the charging voltage to a first set value. a first voltage sensor that detects that the charging voltage is above a second set value; a second voltage sensor that is provided on the output side of the switch and detects that the charging voltage is below a second set value; and the first voltage sensor. A first contact operated by the detection output of the second voltage sensor, a second contact operated by the detection output of the second voltage sensor, and the charging voltage is controlled according to the states of the first and second contacts. A printed circuit board checking device, comprising: a display device that displays that the value is equal to or higher than the first set value or equal to or lower than the second set value.