| 摘要 |
PURPOSE:To perform detection with a contact of a probe, by connecting the primary side of the power supply of a product to be tested to an insulated and pressure-resistant tester via a pickup transformer and carrying out a logical operation for the relation among the probe driving, supply of high pressure and output of the pickup transformer. CONSTITUTION:A probe 4 supplies the high voltage of a tester 3 to a test area 2a of a product 2 to be tested. An end of an attachment plug of the product 2 is also connected to the tester 3 via a self-checking device 1. When a driving signal (b) is delivered to a probe driving circuit 12 from a sequence circuit 6, the probe 4 protrudes to touch the area 2a. Then a control signal (a) is delivered to the tester 3 from the circuit 6 to feed the high voltage to the probe 4 with a delay of a fixed time. As a result, a pulse signal A is delivered to a Schmitt trigger inverter 13 via a pickup transformer 5. On the other hand, a signal B is produced at a pulse control circuit 7 of the device 1 on the basis of the signal (a). An NAND logical operation is carried out at a discriminating circuit 8 for signals A and B. Then an alarm 10 is energized in case the contact of the probe 4 is defective. |
