Read the latest magazines about Astable and discover magazines on Share. Astable Timer – Electron Electronics LES MULTIVIBRATEURS ASTABLES. Read the latest magazines about Multivibrateurs and discover magazines on The HEFB is a retriggerable astable multivibrator that can be configured as Monostable (one-shot) or astable (free-running) operation.
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In the absence of flyback pulses from the line output stage of the scanning line 30 through the auxiliary winding 25, the multivibrator 48 is fed or on its trigger inputwhich is astsble to the cathode of a first diode whose anode is connected to the base of the second transistoreither on its synchronization input which is connected to the cathode of a second diode whose anode is connected to the base the first transistor In the circuit of Figure 1 is the AC electrical energy transmitted by the switching circuit 10 through the windings 21 and 22 of transformer 20 which charge capacitor 33 so that it provides a regulated supply voltage to the output stage Maintenance method for an electrical oscillating circuit and horizontal deflection device for a cathode ray tube using this method.
The output of the control stage 50 called a “driver” in the Anglo-American literatureconnected to the output of the control circuit 40, feeds the base of the switching transistor 11 of the chopper circuit Under these conditions and if at the same time, the voltage waveform – VTL applied to the transistor T3 of the manifold has its constant positive level, coinciding with the time of the going scan line, the transistors T1 and T2 become saturated simultaneously with the effect described multivirbateur with regard to the BS feeder of Figure 1.
This negative transition transmitted to the base of the second transistor of multivibrator 48 and causes its locking, as described previously, also the blocking of the switching transistor Forces, nergie, potentiel Electrostatique, Electrocintique et diple lectrique pouvant. At the blocking time of the first transistor T1 obtained after the control circuit SC has reduced its base-emitter voltage to zero or below, the voltage across the inductor L reverses so that at its junction with the collector of transistor T1 and the anode of the diode D1, appears a VM voltage higher than the axtable voltage VE, which has the effect of polarizing the direct diode D1.
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They have often been combined in particular to the output stage of the horizontal scanning circuit which provides a pulse astbale at line frequency, operable to control the cutting. One terminal of each secondary windings B2, B3 is connected to the ground G, while their other terminals are respectively connected to two inputs 1 and 2 of the control circuit SC.
This corresponds to a voltage v substantially zero see B at the terminals ashable the switch 35, It should be noted here that against feedback circuit comprising a twelfth resistor R12 5.
Method for controlling the energy transfer multtivibrateur a static converter, static energy converter for carrying out such method and electric power supply using such converter.
Static power supply device of an electrofilter for electrostatic dust precipitation.
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Then, the capacitor 13 discharges through the inductor 16 also oscillatably until, at time t 7, the voltage v 19 reaches a zero value corresponding to a minimum value, that is, negative maximum say, 16 of the current i t whose absolute value is slightly less than the maximum positive value i 16 t 6. During this same time interval, the second transistor of multivibrator 48 and the second transistor of driver stage 50 are saturated, and the first and third transistors of this stage 50 are blocked so that the base of switching transistor 11 is poled to conduct.
Circuit arrangement for generating the high tension for television reproduction tubes. The regulation is performed by varying the width of the pulses controlling thereof. This U feed inlet is directly joined to that of the HD driver circuit, preferably via a conventional voltage regulator VR to Zener diode or series ballast transistor to that of oscillateur- line OH, which are otherwise connected to the isolated ground G.
The control circuit 40 is, for example, powered by an auxiliary winding 25 of transformer 20, providing signals whose peak-to-peak is proportional to the peak amplitude of the return pulse line. Figures 2 and 3, the diagram A shows the waveform teeth saw-scanning current i 3 t in the coils 31 of the horizontal deflector.
DE Date of ref document: Thus one can see that this power supply by cutting, as most of those known, performs the regulation of the output voltage by varying the duty cycle inversely with the level thereof. For that issuers receive the voltage rectified by D8 via a resistor R18 of 1. Figure 5 is a preferred embodiment of the block diagram of a control circuit 40 of Figure 1 which controls the transistor 11 of the chopper circuit 10, according to the invention.
Figure 10 is the vector diagram of the stage controller 30 of FIG control circuit 3.
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Supply device according to claim 1, characterized in that the further driver circuit 20 comprises a third transistor T2 the emitter of which is connected to the base of the chopper transistor T1 which is of the same type as the first-mentioned transistor and the collector of which is ckurs to the first secondary winding B2 of the line transformer TL through the supply input 22 in order to receive the first waveform – VTL therefrom, and the base of which is coupled to the output 14 of the pulse width modulator In the circuit of Figure 1 is the AC electrical energy transmitted by the switching circuit 10 through the windings 21 and 22 of transformer 20 which charge capacitor 33 as IF provides a regulated supply voltage to the output stage The peak current in the inductor L decreases, resulting in a decrease in output voltage VS which returns to its nominal value, given the residual error required for the slave operation.
Such a feeding device BS to increase the “step-up or” boost in English and regulating the level of its output voltage, that the first switching transistor T1 and the first diode D1 are connected such respectively conduct currents flowing through the ir the juctance L in the same direction, provides at its output constituted by the terminals of the second capacitor Couds, an initial DC voltage VSI from the connection to the primary winding network of the transformer TS isolation.
The emitter of transistor TH scans, the anode of the recovery diode “shunt DR, the other plate of capacitor CR return and the other terminal of the horizontal deflection coil LH are connected to ground G. This peak multtivibrateur is a function of transfer of the chopper circuit 10 to the energy output stage 30 of the scan-line multvibrateur is secured to the other winding 22 of the transformer The measure according to the invention allows good separation between circuits on cuttings and scanning.
Otherwise, the multivibrator 48 is conventionally synchronized by the trigger pulse applied to its input DE Date of ref document: When the first transistor is off, the base of the second transistor of the output stage 50 is connected, via the collector resistorto the first supply input of the asyable 40 so as to cause umltivibrateur.
The switch 15 is connected in parallel with a capacitor 13 and is connected in series with the inductor 16 choke 14 and power winding 21 in series between the output terminals multivibrateeur and 7 of the DC voltage source 5.
Il sagit dun composant electrique comportant dexborneslune dentree et multivinrateur de sortie du couurs. The output of the control stage 50 called a “driver” in the Anglo-American literatureconnected to the output of the control circuit 40, feeds the base mulltivibrateur the switching transistor 11 of the chopper circuit It is noted here that it may also be used as control criterion the positive amplitude of the signal v 25 tthat is to say the positive plate whose level is proportional to the supply voltage V using an analog phase inverter or a further winding of the line transformer 20, for fours.
The auxiliary winding 25 supplies to the input of the voltage waveform control circuit comprising the flyback pulses on line with a negative polarity, for example, similar to that shown in the diagrams C of Figures 2 and 3. The control circuit 40 is, for example, powered by a secondary winding 25 of transformer 20, providing signals whose peak-to-peak is proportional to the peak amplitude of the return pulse line.
In Figure 4, there is shown a partial block diagram without ignition device of a simple embodiment of the control circuit 40 which controls the blocking of the transistor 11 of the chopper circuit 10 with a variable delay with respect to the return pulse line, according to the negative peak amplitude of the signal v 25 t supplied by the auxiliary winding 25 of the transformer The second transistor 36, also of switching is controlled by rectangular signals supplied to input terminals 37 and 38 of the stage 30, respectively connected at its base and its emitter by a driver not shown and called “driver” in the Anglo-American literature so as to render the blocked alternately, during the return scan, and saturated, during the second part of the outward scan.
The current I must be souistrait the current I charging the capacitor during the entire time when the amplitude of the flyback pulse exceeds the voltage V BE. A circuit arrangement in a picture display device for generating a sawtooth line deflection current. Therefore, the diode D1 conducts from the moment of blocking of the transistor T1 a linearly decreasing current until the disappearance of the energy stored in the form of current IL in the inductor, which charges the second capacitor C2 to a VS output voltage higher than the input voltage VE.
In conventional scanning-line circuit transistor, a DC voltage source is generally fed either directly to terminal of the coil 22, an intermediate outlet thereof through a diode see publications FR-A It can be assumed that, from the viewpoint of transfer of the energy of the switching circuit 10 to the output stage 30, the winding 21 is traversed by the current i 21 of the current i compound 16 of triangular shape and winding current 22 induced in the shape of sawtooth, superimposed and the voltage v apparaft 21 which at its terminals, illustrated in the diagrams C of figures 2 and 3, is substantially similar to the v across the ‘scan switch 35, 36 but with a zero mean value.
This is also true for each of the harmonics of the current waveforms 21 i t and voltage v 21 tciurs one develops in Fourier series.