Abstract: The invention relates to a DC to DC voltage converter including a charge pump capacitor (C) installed parallel to a means (10, 20) for controlling switches (T1, T2), arranged to maintain a predefined voltage range on the terminals of the means (10) for controlling the upper switch (T1). The control means (10, 20) are arranged so as to close the lower switch (T2) in order to impose zero electric potential on the central terminal of the star (O) when the upper switch (T1) is open, in order to force the charging of the charge pump capacitor (C).

Abstract: The invention relates to a DC to DC voltage converter including a charge pump capacitor (C) installed parallel to a means (10, 20) for controlling switches (T1, T2), arranged to maintain a predefined voltage range on the terminals of the means (10) for controlling the upper switch (T1). The control means (10, 20) are arranged so as to close the lower switch (T2) in order to impose zero electric potential on the central terminal of the star (O) when the upper switch (T1) is open, in order to force the charging of the charge pump capacitor (C).

Abstract: A method of controlling a machine including at least one inductive coil (n), the inductive coil being connected to a primary electricity power supply network (RP) via a control circuit comprising, between a connection point (A) of the coil (n) in question and terminals of the primary network (RP), at least one half-bridge of a variator adapted to controlling said machine, the half-bridge being formed by first and second controlled switches (T+n, T?n). In the method, connection point (A) of said coil (n) is connected to at least one third controlled switch (Tn-x), the third switch (Tn-x) constituting a bypass switch connected to at least one secondary electricity power supply network (Rx), and the electrical state of the third switch (Tn-x) is associated with that of the half-bridge.

Abstract: An electronically switched motor includes a stator-rotor assembly fitted with three-phase driving windings, a series of switches for powering the windings, and a control circuit suitable for regulating a speed of the motor as a function of a reference speed and a measured speed. The control circuit includes switch control elements to cause each switch to switch on and off in compliance with a repeated sequence selected to power the driving windings as a function of the reference speed and the measured speed. The sequence includes a succession of on/off pulses with a duty ratio. The control circuit is suitable for generating a first switch control mode for controlling the switches so that the switches are in an ON state or receive a succession of ON pulses over a first activation period and a second switch control mode for controlling the switches so that the switches are in an ON state or receive a succession of ON pulses over a second activation period larger than the first activation period.

Abstract: The motor has a stator and a rotor. One of the elements has coils constituting a three-phase winding and an electronic control module having inputs connected to rotor position sensors and to a speed reference signal (Vc), and including a power circuit for powering the phases from a DC source under the control of a processor. The processor causes the phases to be powered at variable duty ratio so as to regulate speed in a first mode without overlap in time between the periods in which the various phases are powered with voltage pulses, and in a second mode in which there is 33% overlap of power to two phases, and it causes a changeover from the first mode to the second mode when the duty ratio reaches a predetermined value lying in the range 70% to 100%, and a changeover from the second mode to the first mode when the duty ratio falls below another predetermined value.

Abstract: An electronically switched motor comprising a stator-rotor assembly (10, 12) fitted with three-phase driving windings (12) and further comprising a series of switches (20, 22) for powering the windings, and control means (26, 28, 32) suitable for regulating the speed of the motor on a reference speed (Vc), said control means (26, 28, 32) including means (18, 26, 28) for monitoring the relative speed of the stator (12) and the rotor (10), and means for causing each switch (20, 22) to switch on and off in compliance with a repeated sequence selected to power the driving windings as a function of the signals (Vc, Vm) supplied by the speed monitoring means (18, 26, 28), said sequence including a succession of on/off pulses with a duty ratio that is a function of the speed monitoring, the motor being characterized in that the control means are suitable for responding to signals delivered by the monitoring means (18, 26, 28) to generate two modes for controlling the switches (20, 22), the sequence of the second swi

Abstract: The motor has a stator and a rotor. One of the elements has coils constituting a three-phase winding and an electronic control module having inputs connected to rotor position sensors and to a speed reference signal (Vc), and including a power circuit for powering the phases from a DC source under the control of a processor. The processor causes the phases to be powered at variable duty ratio so as to regulate speed in a first mode without overlap in time between the periods in which the various phases are powered with voltage pulses, and in a second mode in which there is 33% overlap of power to two phases, and it causes a changeover from the first mode to the second mode when the duty ratio reaches a predetermined value lying in the range 70% to 100%, and a changeover from the second mode to the first mode when the duty ratio falls below another predetermined value.

Abstract: A roller for a wound ribbon such as a printer ink ribbon may be rotationally coupled by pushing the projections or teeth of a wheel on a drive spindle into a soft material defining part of the bore in the roller. A spring blade prevents the wheel from freely rotating and provides a snap-in feeling. The roller may be part of a cartridge having members for locking the rollers in a position in which the ribbon tension is optimized. The roller and spindle may be coupled in any relative angular position, and the rollers may thus be locked. Release is automatic when the cartridge is full engaged. The ribbon may therefore be more readily installed in an optimized matter.