Pulse step modulator

A method of amplifying an analog frequency signal comprising the steps of:

• providing a plurality of unit step modules connected together in series with each module including a DC voltage source and an associated actuatable switching means for, when actuated, turning on said associated module for providing a unit step voltage of a given magnitude;
• connecting an output circuit to the modules for providing an output voltage to a load wherein the output voltage is a multiple of the unit step voltage in dependence upon the number of the modules that are turned on;
• receiving a said analog signal and responding to the magnitude thereof for sequentially actuating the plurality of switching means in a given order as the magnitude of the input signal increases in value by incremental fixed steps and sequentially de-actuating the switch means in the reverse order as the input signal decreases in value by incremental fixed steps;
• each of said modules exhibiting the characteristic of dissipating heat when turned on with the amount of heat dissipated being a function of the time duration that the module is turned on;
• and,
• equalizing the thermal loading of the modules by thermally coupling selected ones of said modules together as a group of modules with the selected modules of each said group being selected such that the average amount of heat dissipated by each said group is essentially equalized.