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AssigneesCompagnie Internationale pour l'Informatique, Cie Honeywell Bull
InventorMichel Pichon
Estimating the term…
The percent error in the value of a resistor, relative to a nominal value (R.sub.n) of the resistor is determined automatically with a Wheatstone bridge having first and second branches energized by a voltage source. The first branch includes first and second series connected resistors respectively having values P and Q. The second branch includes third and fourth series connected resistors respectively having values R and A; the third resistor is the resistor being measured for percent error. The fourth resistor has a value to establish bridge balance when R = R.sub.n. A diagonal is connected across a common terminal of the first and second resistors and a common terminal of the third and fourth resistors. A voltage source driving the two branches in parallel has a value in accordance with: ##EQU1## WHERE: K = P/Q and is much less than 1, u = the voltage across the diagonal that is directly proportional to the percent error, and m = an integer. The bridge energizing voltage is derived from a fixed voltage source, as well as a variable voltage source that is responsive to the bridge diagonal voltage.
Apparatus for automatically determining the percent error in the value R of an impedance from a nominal value R.sub.n of the impedance comprising a Wheatstone bridge including:
Apparatus for measuring the percentage error in the value of an impedance from a nominal value for the impedance comprising a Wheatstone bridge having first and second voltage dividers, each of said voltage dividers having a tap and being connected across a voltage source having a value E, a voltage detector connected in a diagonal of the bridge between the taps of the first and second voltage dividers, the first voltage divider including impedance means so that the voltage at the tap of the first divider equals Ek/k+1, where k <<1 and is independent of the value of the measured impedance, the second divider including the measured impedance connected between the tap of the second divider and a terminal of the source so that when the bridge is balanced the voltage across the variable impedance equals Ek/k+1;
A method of measuring the percentage error in the value of an impedance from a nominal value for the impedance with a Wheatstone bridge having first and second voltage dividers, each of said voltage dividers having a tap and being connected across a voltage source having a value E, a voltage detector connected in a diagonal of the bridge between the taps of the first and second voltage dividers, the first voltage divider including impedance means so that the voltage at the tap of the first divider equals Ek/k+1, where k is independent of the value of the measured parameter, the second divider including the measured impedance connected between the tap of the second divider and a terminal of the source, so that when a bridge is balanced the voltage across the measured impedance equals Ek/k+1;
Dependencies are inferred from the claim text.