METHOD AND APPARATUS FOR AMPLIFYING A SIGNAL AND TEST DEVICE USING SAME
First Claim
1. An amplifier circuit, comprising:
- a first test terminal;
a second test terminal;
a first output terminal;
a second output terminal coupled to a first fixed voltage; and
an output voltage generator having a first input coupled to the first test terminal, a second input coupled to a second fixed voltage, and an output coupled to the second test terminal and the first output terminal, the output voltage generator being operable to apply to the output of the output voltage generator a voltage having a magnitude equal to the voltage applied to the first input of the output voltage generator referenced to the second fixed voltage and a polarity opposite the polarity of the voltage applied to the first input of the output voltage generator referenced to the second fixed voltage.
0 Assignments
0 Petitions
Accused Products
Abstract
An amplifier circuit is used in a multimeter to amplify signals applied between a pair of test terminals. A voltage applied to one of the test terminals is amplified by a first operational amplifier configured as a voltage follower. An output of the first operational amplifier is applied to an inverting input of a second operational amplifier configured as an integrator. An output of the second operational amplifier is connected to the other of the test terminals. A voltage generated at the output of the second operational amplifier provides an indication of the magnitude and polarity of the voltage applied to the first and second test terminals.
24 Citations
20 Claims
-
1. An amplifier circuit, comprising:
-
a first test terminal; a second test terminal; a first output terminal; a second output terminal coupled to a first fixed voltage; and an output voltage generator having a first input coupled to the first test terminal, a second input coupled to a second fixed voltage, and an output coupled to the second test terminal and the first output terminal, the output voltage generator being operable to apply to the output of the output voltage generator a voltage having a magnitude equal to the voltage applied to the first input of the output voltage generator referenced to the second fixed voltage and a polarity opposite the polarity of the voltage applied to the first input of the output voltage generator referenced to the second fixed voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A test device, comprising:
-
a first test lead; a second test lead; an output voltage generator having a first input coupled to the first test lead, a second input coupled to a first fixed voltage, and an output coupled to the second test lead, the output voltage generator being operable to apply to the output of the output voltage generator a voltage having a magnitude equal to the voltage applied to the first input of the output voltage generator referenced to the first fixed voltage and a polarity opposite the polarity of the voltage applied to the first input of the output voltage generator referenced to the first fixed voltage; a selector operable to control the operation of the test device; a processing circuit coupled to the output of the negative integrating driver circuit and the selector, the processing circuit being operable to provide an output signal indicative of a voltage at the output of the negative integrating driver circuit; and a display coupled to receive the output signal from the processing circuit and being operable to provide a visual display indicative of the magnitude of a voltage applied between the first and second test leads. - View Dependent Claims (12, 13, 14, 15, 16, 17)
-
-
18. A method of amplifying a signal applied between first and second input terminals, the method comprising:
-
generating an output voltage having a magnitude equal to the voltage applied to the first input terminal referenced to a fixed voltage with a polarity opposite the polarity of the voltage applied to the first input terminal referenced to a fixed voltage; and applying the output voltage to the second input terminal. - View Dependent Claims (19, 20)
-
Specification