Sequence component tester
AssigneeUniversal Instruments Corporation
InventorEldred H. Paufve
Life of this patent
Estimating the term…
Abstract
A digitally controlled two legged bridge comprising a component under test and a reference resistor selected from a decade ladder as a function of the exponent of the value of the component under test. A drive signal, whose amplitude is a function of the significant digits of the value of the component under test, and a reference signal are connected to selected points on the bridge in the appropriate waveform as a function of the component under test. The output of the bridge is fed back to the drive signal to balance the bridge and is compared with acceptable percentage error levels, for the component under test.
Claims27
An electrical component sequence tester for a plurality of components of nominal values presented in a predetermined sequence comprising:
- a pair of contacts for electrically engaging in sequence a component therebetween;
- means for forming a two legged bridge using said component between said pair of contacts as a first leg in series with a selected resistance chosen out of a limited plurality of resistors as a second leg;
- means for generating a fixed voltage reference signal and a variable voltage test signal, said means for generating a fixed voltage reference signal including a fixed voltage source inputted to a fixed gain amplifier device;
- and said means for generating a variable voltage test signal including said fixed voltage source inputted to a variable gain amplifier device, said reference signal being the output of said fixed gain amplifier device, and said test signal being the output of said variable gain amplifier device;
- means for selectively applying said reference signal and said test signal each to an opposite end on said bridge;
- means for feeding back the output signal at the junction between said legs of said bridge to said generating means to electrically balance said bridge, said output signal being zero when the nominal value and the actual value of the component on test are equal, said output signal being finite when the nominal value and the actual value of the component on test are unequal;
- means for comparing the output signal at the junction between said legs of said bridge with a predetermined voltage value, said comparison being indicative of the difference between said nominal value and said actual value of the component on test;
- and
- means for controlling said forming means, said generating means, said applying means and said comparing means as a function of the type of test to be performed, the nominal value of the electrical component and an acceptable value of deviation between said nominal value and said actual value.
In a digitally controlled bridge having contacts for receiving an electrical component to be tested as one leg of the bridge and an AC signal generator, the improvement comprising:
- means for rectifying said AC signal;
- and polarity means for selectively coupling the rectified signal of a single polarity to said bridge in response to a binary polarity command, said polarity means includes:
- four photo responsive switching means connected as a bridge across the output of said rectifying means;
- and
- two photo source means responsive to opposite binary polarity commands for activating opposite diagonal pairs of said photo responsive switching means to select said single polarity of said rectified signal.
An electrical component tester comprising:
- means for forming a two-legged bridge using said component on test as a first leg in series with a selected resistance chosen out of a limited plurality of resistors as a second leg;
- means for generating a reference signal and a variable voltage test signal, said means for generating a variable voltage test signal including a voltage source inputted to a variable gain amplifier device, and said test signal being the output of said variable gain amplifier device;
- means for selectively applying said reference signal and said test signal each to an opposite end on said bridge;
- means for feeding back the output signal at the junction between said legs of said bridge to said generating means to electrically balance said bridge, said output signal being zero when the impedance ratio of said legs equals a preferred value, said output signal being finite when the impedance ratio of said legs deviates from said preferred value;
- means for displaying the output signal at the junction between said legs of said bridge, said display being indicative of the value of said component on test.
Dependencies are inferred from the claim text.