Abstract: A data transmitter is provided which performs digital to analog conversion, convolution with an arbitrary finite impulse response, and smoothing of the output functions without requiring a separate anti-aliasing low pass filter. To implement the data transmitter, a digital input data value is convolved with a desired impulse response. The coefficients of the desired finite impulse response filter are chosen to create a first or second derivative of an output of the data transmitter. Then, the derivative is integrated so that a resulting signal output from the data transmitter is a smooth signal which does not require further filtering.

Abstract: A convolutional digital to analog converter (CDAC) according to the present invention enables to apply the convolution operation between the digital input signals and the Fourrier transform of a filtering transfer function. This convolution operation is combined with interleaved sampling performed by a clock splitter and also a multiplier generator device.

Abstract: This overload protection circuit capable of sustaining high capacitive load or any other load which may create an important inrush current, comprises a differential bridge composed of high impedance measuring resistors (R1, R1' R3, R3'), a low impedance sensing resistor (R2), and a timing and control circuit (20) including a transistor (T2), a capacitor (C1) and resistors that controls a switch (T1) and limits the inrush current of the subcircuit capacitor by slowing the closing of the switch. In case of defaults, the switch will be opened fast enough to minimize the fault transient transfer from down-stream to up-stream of the protection circuit. In addition, a comparator (32) associated to a resistor (R31) providing an hysteresis enables to avoid the oscillations in the region of the system transition from on to off states and vice versa. This circuit can be used in a system which comprises a secondary power supply unit (9) which powers a plurality of subcircuits (22).

Abstract: The overload protection circuit 12 comprises a resistor bridge 20 with a low impedance sensing resistor r and high impedance resistors R1 to R4 which generates voltages Va and Vb at the inputs 32 and 34 of a comparator 22. Voltage Vb depend upon the value of the load current so that the comparator provides at its output 36 a control signal for opening the switching device 24 comprising a field effect transistor when the load current exceeds a maximum value. Resistor R5 reinforces the effect of the control signal. This circuit can be used in a system which comprises a central power supply unit 8 which powers a plurality of devices such as 4. The status of the circuit 12 is reported to the system 8 though line 14 and circuit 12 comprises a control circuit 26 which is responsive to set and reset control signals on lines 14 and 18 from the unit 8 to close or open the switch 26.

Abstract: A flexible capacitor (1) includes a dielectric made of flexible material, coated on each side with conductive material for insertion between a cable shield being at the ground potential of a remote electrical machine, and a part on a local machine being at the local ground potential (3, 5, 2) for example at a connector (7) level.

Abstract: A sigma-delta converter including a switching component controlled by a first clock having determined transitions for generating a train of sigma-delta code pulses corresponding to an analog input value. The sigma-delta includes circuits for generating a second clock of a same frequency as the first clock and having a negative transition followed after a defined period of time (d2) by a positive transition. The determined transitions of the first clock controlling the switching element occur during said defined period of time. There is also included a circuit controlled by the sigma-delta code pulse train and said second clock for generating a train of sigma-delta pulses insensitive to the mismatch of the rise and fall times of the switching element thereby improving the linearity and the signal-to-noise ratio of the converter.

Abstract: A conversion system is disclosed for performing either an analog-to-digital A/D conversion associated with an amplification step or a digital-to-analog D/A conversion associated with an attenuation step. The system includes apparatus (115) for receiving a input digital word to be processed, i.e. converted into analog and then attenuated, and apparatus (165) for receiving a input analog value to be processed, i.e. amplified for scaling purposes and then converted into digital. It also includes a digital-to-analog D/A converter (110), an attenuator (120) for attenuating the analog output of D/A converter (110), and a comparator (150) for comparing the value of the input analog value to be processed and the output of said attenuator (120). The processing of the D/A-attenuation process is performed by both the D/A converter (110) and attenuator (120).

Abstract: An active transformer is disclosed of the type which includes two primary terminals to which is applied a voltage v.sub.1 with a current i.sub.1, and two secondary terminals supplying a voltage v.sub.2 with a current i.sub.2. The transformer is characterized in that it includes a first circuit whose input, connected to the primary terminals, generates an input current of the form i.sub.1 ' = jC.sub.1 .omega.v.sub.1 and whose output supplies a current of the form i.sub.2 " = -jN.omega.v.sub.1 to the secondary. The transformer also includes a second circuit whose input, connected to the secondary terminals, generates an input current of the form i.sub.2 ' = jC.sub.2 .omega.v.sub.2, and whose output supplies a current i.sub.1 " = -jN.omega.v.sub.2 to the primary. The terms C.sub.1, C.sub.2 and N are respectively the dual equivalents of the terms L.sub.1, L.sub.2 and M found in the relations associated with a conventional transformer. The currents flow in such a way that they satisfy the relations i.sub.1 = i.