DC CONSTANT CURRENT SUPPLYING CIRCUIT WITH UNSATURATED CURRENT INVERTING FUNCTION

摘要

PURPOSE:To make a DC loop current constant and make the impedance of a current supplying circuit high, by using one transistor switch as a constant current circuit and operating the other transistor switch in the calss ''A''. CONSTITUTION:When level ''1'' is inputted to an input terminal (c), transistors TRs Tr12, Tr10, Tr5, and Tr6 are turned on, and TRs Q6 and Q7 for current inverting switch are turned on, and a current is flowed from an output terminal (a) to an output terminal (b), and this current is limited to a constant value. Meanwhile, since TRs Tr6 and Q7 are operated in the class ''a'', impedances are high sufficiently. When level ''O'' is inputted to the input terminal (c), these TRs are turned off, and a current is flowed from the output terminal (b) to the output terminal (a). In this case, the current is constant also, and a TR Q8 for current inverting switch is operated in the class ''a'', and therefore, the impedance is high sufficiently.