Electric voltage exception protection device used for circuit board test

Abstract

The invention discloses an abnormal voltage protection device in circuit board testing, which is connected between a circuit board to be tested and a test set, and comprises a relay, a singlechip, an A / D converter and a memorizer, wherein, the singlechip is connected with the relay; the A / D converter is connected between one contact point of the relay and the singlechip; the memorizer is connected with the singlechip and is used for storing a standard output voltage of the circuit board to be tested; and the other two contact points of the relay are respectively used for connecting the circuit board to be tested and the test set. Applied to the circuit board testing, the unusual voltage protection device serves the protection purpose reliably when the voltage output by the circuit board to be tested is abnormal, so as to avoid the failure of the test set; and the settings of the device is simple, the universality is good, and the device can be applied to the testing processes of the circuit boards in different types.

Description

【Technical field】 [0001] The invention relates to the technical field of electronic manufacturing and testing, in particular to an abnormal voltage protection device used in circuit board testing. 【Background technique】 [0002] In the field of electronic manufacturing, it is often necessary to test the semi-finished circuit board in the middle of production. The test process often requires expensive test equipment to be electrically connected to the circuit board. If the circuit board to be tested is faulty, the level output to the test equipment is too high If the test equipment is too high, it will cause the test equipment to fail or be damaged. Replacing the test equipment will not only delay production, but also require expensive maintenance costs, which will increase the production cost of the product. Chinese Patent No. 02230708.7 discloses an overvoltage protection device for a test board, which is applied between the circuit board to be tested and the test equipment...

AI Technical Summary

Problems solved by technology

The overvoltage protection device of the test board uses a fuse and a thyristor. When the voltage is too high, the thyristor is turned on, and the current is too large to blow the fuse. The consistency of the fuse and the thyristor is not very good, and it can only be adjusted roughly; secondly, the universality of the protection device is not good, and the threshold value needs to be readjusted for different test objects, which is a complicated process; Then the fuse is blown, the protection is not timely enough, and the subsequent circuits (including test equipment) will still be threatened by instantaneous overvoltage before the protection action

Images