EP 0169488 B1 19911016 - TRANSFORMER CIRCUIT
Title (en)
TRANSFORMER CIRCUIT
Publication
Application
Priority
- DE 3427291 A 19840724
- DE 3502889 A 19850129
- DE 3511182 A 19850327
Abstract (en)
[origin: US4774451A] A voltage controlling transformer circuit comprises a setting unit to the input terminals of which an alternating input voltage is applied and the output terminals of which provide an alternating output voltage the amplitude of which can selectively be changed. For this purpose the setting unit comprises a transformer having a first winding connecting one of the input terminals with one of the output terminals while the other input terminal and the other output terminal are directly connected by a conductor. The transformer also comprises at least one further winding the number of turns of which is greater than the number of turns of the first winding, and to which different control voltages can be applied by means of switches in order to induce in the first winding a voltage the amplitude of which is, in dependence on the winding sense of the further winding, either additionally or subtractively imposed on the amplitude of the input voltage. For switching over from one switching state into another very quickly and smoothly it is provided to close at least one of the switches which must be closed in the "new" switching state, before the first one of the switches which must be open in the "new" switching state, is opened. To prevent impermissible high currents occuring during these switching-over operations current limiting circuits are provided in the current paths leading from the control voltage source through the respective further winding and therefrom back to the control voltage source.
IPC 1-7
IPC 8 full level
G05F 1/30 (2006.01)
CPC (source: EP US)
G05F 1/30 (2013.01 - EP US)
Designated contracting state (EPC)
AT CH DE FR GB IT LI NL SE
DOCDB simple family (publication)
EP 0169488 A2 19860129; EP 0169488 A3 19870819; EP 0169488 B1 19911016; DE 3584401 D1 19911121; US 4774451 A 19880927
DOCDB simple family (application)
EP 85108921 A 19850716; DE 3584401 T 19850716; US 75783185 A 19850722