Transistor and diode tester

Claim 2

Apparatus for testing solid state circuit devices comprising: a. at least three test device input terminals; b. a relatively low voltage AC power source; c. a center zero D.C. voltage minitor having a time constant long enough to be substantially unresponsive to the frequency of said A.C. power source; d. first switching means for selectively alternately coupling single terminal pairs or shorted terminal pairs and a single terminal of the test device in series relationship with said D.C. voltage monitor in parallel relationship across said A.C. power source; and e. second switching means for effectively varying the connection sequence of the input terminals of said test device to said first switching means in such a manner that one position only of said second switching means establishes a known relationship for the connection of the base of a test device to said first switching means.

Claim 3

The apparatus of claim 1 and further including: switching means for varying the relative magnitude of the current from said A.C. power source which is applied across said D.C. voltage monitor and said test device terminals, whereby high or low power devices may be tested either in or out of a usage circuit.

Claim 4

Apparatus for testing solid state circuit devices comprising: a. a relatively low voltage A.C. power source; b. at least three test device input terminals; c. a center zero D.C. voltage meter having a time constant long relative to the operating frequency of said A.C. power source; d. first switching means for selectively alternately coupling single terminal pairs or shorted terminal pairs and a single terminal of the test device in series relationship with said D.C. voltage meter across said A.C. power source; e. indicating means on said D.C. voltage meter for qualitatively indicating the polarity of a test device and the base material (of Si or Ge) of the test device; and f. second switching means for effectively varying the connection sequence of the input terminals of said test device to said first switching means in such a manner that one position only of said second switching means establishes a known relationship for the connection of the base of a test device to said first switching means.

Claim 5

Apparatus for testing solid state circuit devices comprising: a. a relatively low voltage A.C. power source; b. at least three test device input terminals; c. a center zero D.C. voltage meter having a time constant long relative to the operating frequency of said A.C. power source; d. first switching means for selectively alternately coupling single terminal pairs or shorted terminal pairs and a single terminal of the test device in series relationship with said D.C. voltage meter across said A.C. power source; e. indicating means on said D.C. voltage meter for qualitatively indicating the polarity of a test device and the base material (of Si or Ge) of the test device; and f. second switching means for effectively varying the connection sequence of the input terminals of said test device to said first switching means in such a manner that one position only of said second switching means establishes a known relationship for the connection of the base of a test device to said first switching means.

Claim 6

The apparatus of claim 3 wherein said first switching means includes first switch means for selectively varying the magnitude of the A.C. current applied to said test device terminals and second switch means for selectively varying the order in which said test device terminals are connected across said A.C. power source.

Claim 7

The apparatus of claim 4 and further including third switch means for effectively varying the sensitivity of said testing apparatus to provide test states for in or out of circuit and high or low power solid state device testing.

Claim 8

The apparatus of claim 5 and further including potentiometer means for adjusting the magnitude of said A.C. voltage to a predetermined relatively low level which is not harmful to a solid state test device.