| 摘要 |
PURPOSE:To test many switches of units easily and accurately by comparing the reference signals in accordance with the switching signals latched according to switch scannings and the decoder signals according to switch states and making decision. CONSTITUTION:The scan signals for many switches 1-6, 1-7- of a unit 1 to be tested by a switch scan generator 1-3 of the unit 1 control a latch circuit group 2 through delay circuits 8-1-8-3 and the switch signals corresponding to the switches 1-6- are latched in the latch circuits 2-1-2-3, 3-1-3-3, 4-1-4-3 of the group 2. In accordance with these signals, the digital outputs similar to the output of a decoder signal generating circuit 1-5 are formed by a binary-decimal decoder circuit 6, digital switch circuits 7-1-7-3, a reference value generating circuit 10, etc. These outputs and the decoded outputs according to on-off of the switches 1-6- from the circuit 1-5 are compared, and a comparator 11 decides the defectiveness and non-defectiveness of the switches. The results are displayed by an LED13. By such automatic testing, the tests of many switches the unit are tested easily and accurately. |
