This helpful paper is a concise (5-page) exposition of a set of tests on a model of the Silicon Controlled Rectifier using the SPICE 2G network simulator, which runs on VAX11/780 equipment at the University of California at Berkeley. The paper implies that the SPICE 2G simulator has wide use at other universities and in industry. The SPICE 2G simulator is used to develop models of circuits which contain active and passive elements and has been in use since the early 1970s. The SCR model used is a macromodel in which the device is considered to be a set of ideal black boxes consisting of perfect diodes, resistors, current sources and voltage sources, etc. The macromodel is compared with an SCR model which is based on the two transistors analogy where the characteristics of the two transistors must be computed from SCR parameters. The authors consider the macromodel to be superior and indicate that the model has been validated experimentally in power control circuits.

Examples are provided of the SCR connected as a half wave rectifier to an inductive load, and of the SCR connected in a self-switching chopper with a RL load together with a RC snubber circuit across the rectifier. Computer typewriter plots of selected currents and voltages in the circuits are provided.

The paper provides an idea of how the model operates in practice. Run times appear to be of reasonable length and are described as being shorter than those provided by the two transistors model. There appears to be a minor misprint in the paper in the equations describing the circuit operation. For those with an interest in the application of the SCR, the technique should be of interest. The authors point out the restrictions of the simulator relating to steady state conditions and the issue of anomalous oscillations created by stiff differential equations.