(under subclass 291) Systems, wherein (1) the supply circuit of the load device includes at least two impedances, means being provided for selectively connecting either of the two impedances in the supply circuit of the load device, or (2) the regulator in the supply circuit of the load device is designed to have its impedance varied over a range of values, means being provided to preselect the value of the impedance to be connected in the circuit and means being provided to effect a transition from one of the impedance values and to stop such transition at the preselected impedance value.
(1) Note. The systems in this subclass are designed to energize the load device with current of one intensity and while the load device is energized to preselect the value of the impedance which is to be connected in the circuit for the subsequent energization of the load device.
(2) Note. The systems in this subclass are often used to control stage and theater lights.
SEE OR SEARCH THIS CLASS, SUBCLASS:
292, for preselectable regulator systems of the keyboard or pattern controlled type.
314, for plural load device systems which include preselectable switching means.
