Telephone installation
AssigneeSiemens Aktiengesellschaft
InventorEberhard Schmid
Life of this patent
Estimating the term…
Abstract
The invention relates to an overvoltage protected high-voltage integrated circuit and a low-voltage integrated circuit with switching control for a hybrid circuit connected peripherally to a telephone exchange for serving telephone instruments. In particular it serves to provide battery feed, ringing voltage generation, and voice signal transmission. Essentially the circuit includes a transformer for transmission of high-frequency energy to the high-voltage circuit, which incorporates transfer of signal currents through four high-resistance, pair-organized symmetrical voltage dividers. The circuit further includes a ringing signal generating arrangement that is activated by means of a voltage increase applied to the high-voltage circuit supply voltage.
Claims13
Circuit arrangement for a telephone system disposed between a telephone exchange and a telephone instrument , the circuit arrangement being connected to the telephone instrument via two telephone wires;
- and comprising:
- current feed means for providing current feed for the telephone instrument;
- an integrated low-voltage circuit section ;
- a high-voltage circuit section connected to said telephone instrument ;
- a switching regulator included in the low-voltage section controllingly engaging the high-voltage section, a transformer having a primary winding connected to said switching regulator and a secondary winding connected to the high-voltage section for providing galvanic isolation between the switching regulator and the high-voltage section, and a first and a second pair of high-resistivity voltage dividers for providing two-way galvanic control signalling between said low-voltage section and said high voltage section.
Dependencies are inferred from the claim text.