Abstract: A voltage measurement circuit is provided which converts a voltage of a first voltage source connected in series with an offset voltage source to an output voltage, including first and second current mirrors for accurately measuring voltage so as to provide a proportional output voltage with the offset voltage removed. Further, voltage measurements can be precisely determined for each of a plurality of voltage sources, such as a plurality of electrochemical cells in a series electrical connection. By virtue of the voltage measurement circuit, the effect of different offset voltage values on the measured voltage is minimized. Also, the voltage measurement circuit exhibits enhanced stability to variations in operating temperature. Accordingly, accuracy of voltage measurements where offset voltages are present is improved.

Abstract: A telescope housing has a removable finger accommodating ring secured thereto. The ring is coupled to the housing by a V-shaped spring member which is inserted into a channel member located on the telescope housing. In this manner, various telescope assemblies of different magnification can be accommodated by the use of the removable ring which also enables convenient storage.