AEDNET: A simulator for nonlinear networks

AEDNET is a system of digital computer programs for simulation of both linear and nonlinear electronic circuits. The system has two main features: 1) the ability to simulate the behavior of a wide class of nonlinear networks, and 2) the on-line use of a digital computer and its oscilloscope display unit for on-line interaction. AEDNET is written in the AED-0 language and it operates on the Project MAC time-sharing computer and the Electronic Systems Laboratory display unit. AEDNET simulates networks whose elements are nonlinear time-varying capacitors, resistors, inductors, and dependent and independent sources. The network is required to satisfy certain topological conditions, and the elements' characteristics are required to satisfy suitable Lipschitz conditions. Non-linear characteristics are represented in the computer either by a table or a subroutine. Elements with nonmonotonic characteristics are allowed, and the elements' characteristics are required to be continuous but not differentiable. Input to the program is given mainly by drawing the network diagram on the face of the oscilloscope, and assigning values to the network elements by typing on the console's teletype or by drawing the elements' characteristics. The output of the program gives the waveforms of the various network variables. Each variable can be displayed on the oscilloscope as a function of time or as a function of another network variable. After a network has been specified and the response calculated and displayed, the user can modify the network by changing both elements and topology, and then ask for a recalculation and redisplay. The object of this paper is to give a general description of AEDNET and a detailed consideration of the part of the system which sets the network equations and calculates the network response.