Abstract: A magnetic valve uses neodymium magnets to maintain itself in a state, either closed or open. Upon applying electrical signals to a coil, the valve state is changed. In the open state fluid may readily flow through the valve, whereas the closed state uses one or more magnets to seal a valve member such that fluid flow is blocked. In the open state, the magnitude of the electrical signal can be varied to vary the effective size of the opening through which fluid may flow, thereby providing proportional control. Importantly, the valve is controllable by a computer using a MIDI card such that the valve is especially suitable for adapting a player piano to operate from a computer. Additionally, the valve may be used in a sprinkler system, a fire suppression system, or various other applications.

Abstract: An appartus for controlling a mechanical music-maker, such as a player-piano has a multiplicity of mechanical actuators and uses a vacuum as the motive force therefor. The mechanical actuators, which actuate corresponding musical keys, are each controlled by a valve which connects the vacuum to the mechanical actuator when opened. The valve is opened when the vacuum side thereof is vented to atomsphere by the first venting system. A second venting system is provided, which can be isolated from the first venting system. The second venting system utilizes electrically energizable solenoid valves to control the venting of the vacuum side of each valve when the first venting system is isolated therefrom.