Abstract: The padless touch sensor is used for detecting a touch at a sensing location onto a dielectric element by a user coupled to earth. The sensor comprises a conductive plate attached under the dielectric element and in registry with the sensing location. A predetermined potential is applied on the conductive plate. Simultaneously, test pulses are produced into earth. When the user touches the dielectric element at the sensing location, a potential variation in the conductive plate is produced during a test pulse due to a capacitive circuit formed between earth, the user and the sensor. No deposition of conductive pads on the dielectric element or other special processes are required. Foreign matter or objects placed directly on top of the dielectric element will not erroneously produce a touch condition.

Abstract: A charge-sensitive switch is described sensitive to the adjacency of, or transfer of charge from a person, for controlling lamps, appliances, motors, etc. The switch contains an over-current sensor for detecting excess load current, and takes action to shut off the current. It can also switch successive loads, as would be required in a tri-light lamp. The input sensitivity of the switch is adjustable so as to be able to switch in the presence of an adjacent charge, as would be required for proximity detection in a burglar alarm.