Constant voltage, current and power circuits; a network synthetic approach

A network theoretic approach is employed to derive a number of circuits for i) constant load current, ii) constant load voltage, and iii) constant magnitude input current, when the load varies over a wide range. It is shown that a circuit delivering constant power to a varying load does not exist, and that the range of load, over which the power does not fall below a specified fraction of the maximum value, bears a constant ratio to the load corresponding to the maximum power