Method of Detecting Burned Fuses in Remote Units Under Test
Original Publication Date: 1984-Oct-01
Included in the Prior Art Database: 2005-Feb-05
A technique is described whereby a central computer is used to detect defective fuses in circuit boards being tested. With as many as 128 circuit boards under test at the same time, it is essential to isolate any defective CUT (card under test), so as not to damage other CUTs. In the circuit as shown in the Fig. 1, the presence of voltage at each of the CUT power supplies 10 provides input voltage to optocouplers 11 when fuses 12 are intact. Current through couplers 11 causes output voltage at pin 6 to be at near ground potential. Should one of the fuses 12 become defective, current through the corresponding optocoupler 11 will cease to flow. Light-emitting diodes 13 provide the operator with a visual indication of the defective fuse.