Abstract:
A device (10) for controlling the linearity of a horizontal deflection stage (1) comprising a deflection yoke (6) supplied with a yoke current (ig) controlled by a switch (2, 4), and series connected to a capacitor (7) for varying the yoke voltage according to the phase of the yoke current (ig); the device (10) comprising a circuit (11, 12) for detecting and generating a real signal proportional to the yoke current (ig); a ramp generator (13-15) for generating an ideal ramp signal having rising portions defining a given S-shaped waveform; and an error amplifier (16) for receiving the real and ideal ramp signals and generating an error signal for driving a power transistor (17) having its emitter and collector terminals connected parallel to the capacitor (7), for modifying the voltage in the capacitor so that the yoke current assumes the required waveform.
Abstract:
A broad operational range, automatic device for the change of frequency in the horizontal deflection of multi-synchronization monitors comprises an integrated circuit (2) incorporating, a frequency meter (3) being input an analog synchronization signal (S1), a phase comparator (14) having two inputs (15,16) and in turn receiving said synchronization signal (S1) on one input (15), a voltage (Vc)-controlled oscillator (12) adapted to output a signal (S3) whose frequency is depending on said voltage (Vc) and operatively linked to an output (22) of said phase comparator (14), and a counter (9) connected with its input, on the one side, to the oscillator (12) output, and on the other side, to the meter (3) output, said counter having an output (21) connected to the other input of the phase comparator (14) also forming the integrated circuit (2) output.
Abstract:
The invention relates to a voltage regulator of the type comprising a linear filter (2), a comparator (3), and a stretcher filter (4) which are connected in cascade with one another between an input terminal (I1) and an output terminal (O1) of the regulator (1), the input terminal (I1) receiving an error signal (ERR) as converted by the comparator (3) into a square-wave error signal (ERRq), and the output terminal (O1) delivering a square-wave output control signal (Sout) which has a stretched duty cycle over the square-wave error signal (ERRq) by a time delay (t A ) introduced from the stretcher filter (4). The regulator of this invention further comprises a non-linear filtering section (5) for the error signal (ERR) which is connected between the input terminal (I1) of the regulator (1) and the linear filter (2) and has linear gain with the error signal (ERR) below a first value (X1), gain approximately of unity with the error signal (ERR) between the first value (X1) and a second value (X2), and zero gain with the error signal (ERR) above the second value (X2). The invention also concerns a method for filtering a noisy electric signal.
Abstract:
This generator of periodic signals with exponential edges, which may be integrated at low cost, comprises a current source circuit (13) connected to a capacitor (11) and to a resistive element (12) to supply them with currents having mutually correlated amplitudes, an amplifier (14) interposed between the capacitor and the resistive element and adapted to maintain the voltage drop on the resistive element proportional to the voltage drop on the capacitor, and a switch device (15), connected in parallel to the capacitor and periodically switched off to allow the discharge of the capacitor.
Abstract:
A reference voltage generator having a dual slope temperature characteristic, for use in an automotive alternator voltage regulator, comprises a bandgap circuit (R1,R2,R3,R4) which generates a voltage (A) having a thermal drift coefficient of zero and a voltage (B) having a non-zero thermal drift coefficient. These voltages are applied to a voltage divider (R5,R6) and a voltage-follower type of circuit (OPA1). A unidirectional conduction amplifier circuit (OPA2) has an input terminal connected to an intermediate point (C) on the voltage divider. A second voltage divider (R7,R8) is connected between the output terminals of the voltage-follower circuit (D) and the amplifier circuit (E). An intermediate node (F) of the second voltage divider is coupled to an output terminal (VREF) of the generator.
Abstract:
A broad operational range, automatic device for the change of frequency in the horizontal deflection of multi-synchronization monitors comprises an integrated circuit (2) incorporating, a frequency meter (3) being input an analog synchronization signal (S1), a phase comparator (14) having two inputs (15,16) and in turn receiving said synchronization signal (S1) on one input (15), a voltage (Vc)-controlled oscillator (12) adapted to output a signal (S3) whose frequency is depending on said voltage (Vc) and operatively linked to an output (22) of said phase comparator (14), and a counter (9) connected with its input, on the one side, to the oscillator (12) output, and on the other side, to the meter (3) output, said counter having an output (21) connected to the other input of the phase comparator (14) also forming the integrated circuit (2) output.
Abstract:
This generator of periodic signals with exponential edges, which may be integrated at low cost, comprises a current source circuit (13) connected to a capacitor (11) and to a resistive element (12) to supply them with currents having mutually correlated amplitudes, an amplifier (14) interposed between the capacitor and the resistive element and adapted to maintain the voltage drop on the resistive element proportional to the voltage drop on the capacitor, and a switch device (15), connected in parallel to the capacitor and periodically switched off to allow the discharge of the capacitor.