Abstract: An electrical controller for actuating a number of electrical devices in accordance with control inputs received from a number of control input sources includes a number of optical isolators having inputs coupled to the control input sources. The optical isolators function to electrically isolate each of the control input sources from each other and to provide individual control voltages corresponding to the control inputs received from the control input sources. The outputs of the optical isolators are coupled through a user-actuable matrix switch to the coils of a number of relays which, in turn, control the electrical devices. Through various settings of the matrix switch, various ones of the electrical devices can be actuated in response to control inputs received from particular ones of the control input sources. Electrical isolation is maintained among the control input sources to avoid the development of undesirable feedbacks to the non-actuated control input sources.