Modular switching system

Switching apparatus comprising a plurality of logic circuits connected in cascade, each of said logic circuits being responsive to a train of address pulses for subtracting one pulse and transferring the remainder to the succeeding logic circuit and for providing an output signal when said train includes only a single pulse, and switch means associated with each logic circuit and adapted to control apparatus external to said logic circuit in response to the output signal therefrom.

Switching apparatus comprising a plurality of switch modules connected in cascade and defining a signal bus, each of said modules having signal terminals for connection of an external unit thereto, logic means associated with each module, each of said logic means being responsive to a train of address pulses for subtracting one pulse and transferring the remainder to the succeeding logic means and for providing an output signal when said pulse train includes only a single pulse, and switch means associated with each logic means and responsive to the output signal therefrom for connecting said signal terminals to said signal bus.

Switching apparatus for selectively connecting a single device in a group of similar devices to a common signal bus comprising means for providing a pulse train having a predetermined number of pulses, a plurality of logic means connected in cascade to receive said pulse train, switch means associated with each of said logic means and arranged to operate in response to an output signal from the associated logic means to connect an associated device to said signal bus, each associated switch means and logic means having an address corresponding to its position in the cascade, said cascade of logic means being responsive to said pulse train to cause the logic means having a position in the cascade corresponding to the number of address pulses in the train to provide an output signal to its associated switch means, whereby any device may be connected to the signal bus by providing a number of address pulses corresponding to the position of the switch means associated with said device.

A method for selectively connecting a single device of a group of similar devices to a common signal bus comprising the steps of providing switch means for connecting each of said devices to said signal bus and switch operating means for each switch means, arranging said switch operating means in cascade, assigning an address to each said switch operating means in accordance with its position in the cascade, providing a train of pulses to the cascade of switch operating means, the number of pulses in said train corresponding to the address of the switch operating means for the desired switch means, subtracting one pulse from said train at each switch operating means and passing the remainder to the succeeding switch operating means, and causing the one of said switch operating means which receives only a single pulse to operate its associated switch means.

A switching system for selectively connecting one component from each of a number of groups of components to form a system comprising a plurality of cascades of switch modules, the number of cascades corresponding to the number of different types of components in said system, the number of switch modules in the respective cascades corresponding to the number of each type of component available, each cascade defining a signal bus for a type of component, the signal buses of the various cascades being connected to form said system, each switch module in each cascade having signal terminals for connection of a component thereto, logic means responsive to a train of address pulses to its cascade for providing an output signal when the number of pulses in said train corresponds to its position in the cascade, and switch means associated with each logic means and responsive to the output signal therefrom for connecting said signal terminals to said signal bus, said switching system further comprising means for providing a train of address pulses to each cascade, each train having a number of pulses corresponding to the position of a particular component in the cascade, whereby one component of each type may be selectively connected to the signal bus to form said system.

In a system for comparing the performance of audio speakers having different power efficiencies, said speakers being selectively connectable to a signal source, programmable signal dampening apparatus comprising a damping circuit associated with said signal source, said damping circuit being programmable to provide a selectable amount of attenuation of signals provided to a speaker connected to said signal source, a plurality of damping selector modules each associated with a corresponding said speaker, each damping selector module including means for programming an amount of attenuation for said damping circuit in accordance with the power efficiency of the corresponding said speaker, and means for enabling the programming means of one of said modules to program said damping circuit when the corresponding said speaker is connected to said signal source, whereby the magnitude of the signal provided to said speaker by said signal source is automatically adjusted in accordance with the power efficiency of said speaker.