Research on Constant-current Characteristics of Howland Current Source Used in Bioelectrical Impedance Detection / 生物医学工程学杂志
Journal of Biomedical Engineering
;
(6): 290-294, 2015.
Article
in Chinese
| WPRIM
| ID: wpr-266684
ABSTRACT
This study aims to analyze and improve Howland current source circuit and to study the constant current source of alternating current with high output impedance and high stability. A simulation study was carried out on the constant-current characteristics of Howland current source from two aspects of resistance match value and the selection of Op amp parameters, and then the output impedance was analyzed. The simulation experiment showed that when it was with the best matched resistance, the constant-current characteristics of Howland current source was better. Op amp parameters could affect the constant-current characteristics of Howland current source. In Howland current source circuit, the current source after parameter optimization had better output impedance and load capacity. The results showed that there was the best matched resistance in the selection by Howland current source. The Op amp with large broadband, high slew rate and open loop gain, and wide range of power supply voltage is more suitable for the bioelectrical impedance detection circuit.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Electric Power Supplies
/
Electric Impedance
/
Electricity
Type of study:
Diagnostic study
Language:
Chinese
Journal:
Journal of Biomedical Engineering
Year:
2015
Type:
Article
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