Signal Source for Compressor Analog: 4,419,735

An improved driving signal source for an electrical analog of a reciprocating compressor generates a variable frequency sinusoidal output. The ratio between the electrical frequency used by the analog and the mechanical frequency of the modeled compressor is controlled by a ratio set switch. Upper and lower limits of the mechanical speed are operator determined, and the electrical output frequency is varied between the corresponding upper and lower electrical analog frequencies. The instantaneous output frequency of the improved source is displayed in terms of mechanical compressor speed. The ratio of electrical to mechanical frequency can be changed independently of the upper and lower mechanical speed settings.