| 摘要 |
<p>The state of operability of a semiconductor device (1), e.g. a TRIAC, is tested by introducing narrow switching pulses into its normal control signal (7, 8) and sensing the resulant momentary change of state. Sensing is by means of a light emitting diode (13, 16) connected in parallel with the device (1) so that when sufficient voltage appears across the device terminals, as in the non-conducting state, the diode (13, 16) will be illuminated. The L.E.D. output is received by a photo-responsive device (20, 19) and corresponding signals (21) supplied to means for correlating these with the original introduced test pulses. Lack of correspondence between these indicates that the semiconductor (1) is inoperable. </p> |
