Abstract: An apparatus and method for interfacing a communication device, such as a Customer Premise Equipment (CPE) to different telephone networks. The telephone networks typically provide a voltage of 48 volts to the CPE. However, this DC voltage tends to fluctuate. Furthermore,the impedances of the telephone network varies. The apparatus provides a constant current to the communication device while coupled to different telephone networks. Since most communication devices use amplitude modulations for transmitting data, a constant DC biasing current is desired. The apparatus can sense load impedances of the telephone networks, and dynamically adjust the current source so that DC biasing currents remain relatively constant. The apparatus is coupled to the telephone network so that communication between the communication device and the telephone network is optimized.

Abstract: An apparatus and method for providing a ringing voltage to a communication device such as a telephone or a modem. Typically, communication devices are coupled to a ringing voltage providing telephone network, such as a Plain Old Telephone Service (POTS) network. The POTS network generally provides the necessary ringing voltages to the communication device. However, in other telephone networks, such as a PBX system, ringing voltages are not provided by the telephone network. The apparatus provides ringing voltages to the communication devices coupled to the non-ringing voltage providing telephone networks. The apparatus includes a switching regulator that provides the necessary ringing voltages to an indicator such as a bell or other output indicator.

Abstract: An improved envelope opener comprising first, second and third shear stations for shearing three edges of an envelope in sequence one edge at a time. Each shear station sequentially aligns the envelope by contacting the edge to be sheared, shears the contacted edge, and then releases the envelope. Each shear station includes a self-sharpening and self-aligning anvil assembly comprising a pivotable anvil which is spring-urged to an adjustable home position. The home position of the anvil is adjusted by means of a rotatable eccentric stop. During a shearing operation, the anvil is pivoted away from and then back towards the home position. An overly thick envelope will keep the anvil pivoted away from the home position to avoid a jam condition at the shear station. A peel back station downstream of the last shear station peels back the top panel of the envelope to expose the contents thereof.

Abstract: An envelope opener comprising first, second and third shear stations for shearing three edges of an envelope in sequence one edge at a time. Each shear station sequentially aligns the envelope by contacting the edge to be sheared, shears the contacted edge, and then releases the envelope. A microcomputer monitors the advance of the envelope through and between the shear stations and causes the shear stations to cyclically align, shear and release the envelope. A peel back station downstream of the shear station peels back a panel of the envelope to expose the contents thereof. If an envelope is jammed at or between any of the stations, the microcomputer actuates a display to indicate a jam condition. The microcomputer also shuts off power to the opener to prevent damage to the envelope.