Solid State Switch Resistance Compensation for Current To Potential Converting Circuits and the Like
Original Publication Date: 1981-Sep-01
Included in the Prior Art Database: 2005-Feb-12
This circuit arrangement incorporates a two-pole-n-throw solid state switch in an exemplary electric measuring circuit for substantially eliminating the disadvantage of solid-state switches where the switch ``closed'' typically interposes a resistance varying between 25 and 1000 ohms which is upsetting to the accuracy of the measurement. For example, in electrochemical analysis apparatus having eight decades of current sensitivity requiring appropriate range switching, accuracy may suffer up to 25%. By adding a solid-state switch section for each range switching section, the relatively heavy current flow is confined to the feedback resistance path and only a light measuring current traverses the feedback resistance element and the measuring switch section for greatly reducing the error.