Current sampling system and method for calculating offset voltage of operational amplifier
A current sampling, offset voltage technology, applied in the direction of measuring current/voltage, measuring electrical variables, measuring devices, etc., can solve problems such as current inaccuracy
Active Publication Date: 2013-04-24
EMERSON NETWORK POWER CO LTD
View PDF5 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0004] The technical problem to be solved by the present invention is to provide a current sampling system for accurately sampling current signals in view of the above-mentioned defects in the prior art that the current sampled by the current sampling system is inaccurate due to the inherent zero drift of the operational amplifier
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0037] Such as image 3 As shown, in the logic diagram of Embodiment 1 of the current sampling system of the present invention, the current sampling system includes a first operational amplifier U1, a second operational amplifier U2, a rectification unit U3 and a controller U4 connected in sequence. First, input the first input signal at the input terminal of the first operational amplifier U1, the first input signal is isolated by the first operational amplifier U1 in turn, amplified by the second operational amplifier U2, rectified by the rectification unit U3 and converted into the first output signal and output to the controller U4; then, input the second input signal at the input terminal of the first operational amplifier U1, the second input signal is isolated by the first operational amplifier U1 in turn, amplified by the second operational amplifier U2, rectified by the rectifier unit U3 and converted is the second output signal and output to the controller U4. Then,...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention relates to a current sampling system and a method for calculating offset voltage of an operational amplifier. The current sampling system comprises a first operational amplifier, a second operational amplifier and a rectifier unit which are connected in sequence, wherein the first operational amplifier is used for isolating sampled signals, the second operational amplifier is used for amplifying the isolated signals, and the rectifier unit is used for rectifying the amplified signals. The current sampling system further comprises a controller, wherein the controller outputs offset voltage according to a first output signal and a second output signal, so as to compensate the null drift of the first operational amplifier and the second operational amplifier; the first output signal adopts the signal output by the rectifier unit when the first operational amplifier is inputting a first input signal; and the second output signal adopts the signal output by the rectifier unitwhen the first operational amplifier is inputting a second input signal input. According to the technical scheme, the offset voltage can be calculated according to the two output signals to compensate the null drift of the first operational amplifier and the second operational amplifier, so that the current sampling system can be used for sampling current accurately.
Description
technical field [0001] The invention relates to power electronics technology, more specifically, to a current sampling system and a calculation method for the offset voltage of an operational amplifier. Background technique [0002] figure 1 It is a logic diagram of a current sampling system in a PFC (Power Factor Correction, power factor correction) circuit of the prior art. In this current sampling system, the sampled current signal is sequentially isolated by the operational amplifier U1 and amplified by the operational amplifier U2 , the rectification unit U3 rectifies the input to the main controller U6, and the main controller U6 performs power factor correction according to the rectified signal. Therefore, the accuracy of the sampling current of the current sampling system directly affects the PF (Power Factor, power factor) of the PFC value and THD (Total Harmonic Distortion, total harmonic distortion) value. [0003] combine figure 1 and figure 2 , if it is spe...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01R19/00
Inventor 沈得贵茹永刚吕华军孙静
Owner EMERSON NETWORK POWER CO LTD