Abstract: The coin identification device comprises a gravity fed chute structure having an opening for receiving a coin to be identified, walls to guide the coin as it moves through the chute and an opening for the coin to exit. A wake-up circuit with sensing coils mounted near the chute opening provides an output signal when the presence of a coin is detected. Two coin sensing circuits, each having an oscillator with a particular coil arrangement are used to sense the characteristics of the coin passing through them. The first coin sensing circuit includes a coil arrangement having a coil mounted on the chute with its axis in the direction of the coin path such that the coin will pass through it and forming part of a first oscillator to create lines of flux parallel to the coin path.

Abstract: A door key is held in a tray which is slidably installed in a container. The tray is retained in the container by a form member pivotally mounted on the container which engages a latch on the tray. A shackle is removably attached to the container for use in retaining the container to a door knob or the like. The shackle has a notched arm which engages a fork member pivotally mounted on the container, thereby retaining the shackle in a closed position. A motor which rotatably drives a drive gear is mounted in the container. When the motor is driven in a first direction, the drive gear drives a tapered release wheel which operates to release the fork member from engagement with the key tray latch, thereby permitting the key tray to be removed. When the motor is driven in an opposite direction, the drive gear drives a second tapered release wheel so as to disengage the notched arm of the shackle from its associated fork member, thereby permitting the shackle to be moved to an open position.

Abstract: A switch for use in an AC circuit wired in a three-way switch mode for supplying power to a load, has a first terminal for connection to an external line, second and third terminals for connection respectively to corresponding terminals of a second like switch, and a switch contact for selectively connecting the first terminal to either one of the second and third terminals. A transformer has its primary winding connected between the first terminal and the external line, and its secondary winding deriving an output voltage therefrom. The output voltage is rectified and supplied to a light-emitting diode. The ratio of turns of the windings of the transformer is such that the rectified voltage energizes the light-emitting diode when power is supplied to the load over its normal operating range. The light-emitting diode will thus provide an indication of when power is supplied to the load.

Abstract: A service circuit for a local telephone line in a building wired with quad telephone conductors, including a tip and ring lead pair continuous with a subscriber's line connected to a remote switching machine, and a service lead pair within the building. A special service circuit is connected to the tip and ring lead pair and to the service lead pair. A control unit is also connected to the tip and ring lead pair and the service lead pair for receiving signals over either the tip and ring pair or the service lead pair from a telephone connected to the local line, and for generating a predetermined special service circuit enabling signal on the service lead pair. The enabling signal is received by the special service circuit which implements one or more special services in response thereto. The control unit also applies operating power to the service lead pair. The special services implemented include intercom, paging, tone ringing, etc. The control unit also provides power, control, rapid dialing signals, etc.

Abstract: A telephone system used in the home which provides special services such as intercom, paging, remote turn on or off of power contacts, audio monitoring, etc. A central control is interposed between the subscriber's line and the local wiring in his home, or is connected in parallel thereto. One or more telephone subscriber sets are plugged into the wiring as usual, contacting the tip and ring leads. In the present invention, remote special service circuits are plugged into the telephone line, contacting the remaining two conductors, referred to below as the black B and yellow Y leads. Each of the remote special service circuits has a specialized function, e.g., a typical circuit will have a speaker, an amplifier for driving the speaker, and a circuit for enabling the amplifier and connecting it across the black and yellow leads once an address has been received on the black and yellow leads.

Abstract: A printer control system which facilitates monitoring of a telephone line and recognition of a predetermined series of digits as they are being dialed. An alphanumeric display displays the digits printed by a printer and which otherwise would be hidden by the printer until the complete number has been dialed and/or the call terminated. The system automatically monitors a subscriber's line, and provides an alarm when a predetermined sequence of digits have been dialed, allowing the operator to divert his attention to other tasks.

Abstract: A call denial apparatus for identifying a telephone subscriber's line out of a group, whereby access to a trunk is denied in the event the subscriber dials one or a group of predetermined digits. A subscriber not to be denied access to the trunk is identified by applying a tracer signal to the seized trunk and the tracer signal on one of the group of subscribers' lines is detected. Accordingly specially modified telephone sets and lines are not required.