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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Various combinations of scan circuits and switching power supplies have been described, for example in the patents or patent applications French publication numbers 2,, 2,, 2, 2, and 2,, where asyable is also carried out using the variation of the cyclic ratio of the saturated and blocked states of the switching transistor or chopper which in some cases is also used multivibrateir the active element of the output stage final of balayage- circuit line or the driver stage controlling thereof.

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It can be assumed that, from the viewpoint of transfer of the energy of the switching circuit 10 to the output stage coirs, the winding 21 is traversed by the current i 21 of the current i courz 18 of triangular shape and winding current 22 induced multivibfateur the shape of sawtooth, superimposed and the voltage V 21 appears at its terminals, as shown in the diagrams C of figures 2 and 3, is substantially similar to that V at the terminals of the ‘scan switch 35, 36 but with a zero mean value.

Photoelectron spectroscopy of As[sup ], As[sub 2][sup ], As[sub 3][sup ], As[sub 4][sup ], and As[sub 5][sup ] Documents. To stop the feed, and also that of Figure 11, just cut, using a remote control receiver parexem- ple, the operation of the scanning-line oscillator.

This is indicated in Figure 8, wherein the diagram A shows the voltage waveform v 25 t across the auxiliary winding 25, the flyback pulses have three different amplitudes V 25 BV 25 and V 25 F N, the diagram B shows the voltage waveform of the capacitor terminals corresponding to these three pulses of line return, and the diagram C represents the collector voltage v t of comparator transistor Il sagit dun composant electrique comportant dexborneslune dentree et lautre de sortie du courant.

In those circumstances, the gain is sufficient for not using a discrete T2 driver transistor and directly connect the cathode of diode D3 to T10 base entry. The pulse which controls the closure of the switch the saturation of the switching transistor begins here with the leading edge of the return pulse line and its duration or length is adjusted according to the current supplied by the load and the variation of the rectified and filtered voltage, so that its end controlling the opening of the switch the blocking of the transistor of cutting occurs during the horizontal scanning go.

Considerons un vecteurOP de module Vm tournant autour du poit O dans le senstrigonometrique avec une vitesse angulaire constante. 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. This winding 21 of line transformer 20 whose primary winding is usually connected in parallel with the coils of the line deflection in the circuit of the output stage 30 of the scan line to provide via secondary windings of the voltage supply, in particular cathode ray tube will be called in the following power winding, because the transfer of energy between the chopper circuit 10 and the output stage 30 will be conducted through it.


These pulses can trigger a flip-flop of variable duration depending on the error voltage supplied by a comparator in the form of differential amplifier, whose one input receives a voltage corresponding to either the positive amplitude of 21 Astabke t proportional to the voltage V 33 V at the terminals of the supply capacitor 33 of the output stage 30 or to the peak-to-peak pulse of flyback, that is proportional to THT, or a combination of these two criteria.

The power supply U of the scanning-line circuit SH input is connected, in addition, one terminal of the primary winding of the line B1-transformer TL, AB whose other terminal is connected, in parallel, to the collector of another TH switching transistor of NPN type, said scan transistor, the cathode of a second diode DR, called parallel recovery, one plate of another capacitor CR, said capacitor return line, and one of the plates of an additional capacitor CS, said effect capacitor “S or go, which supplies the horizontal deflection coil LH, one terminal is connected to the other frame, while the intervals go scanning.

The rising edges of the pulses supplied by the output of the rocker 41 substantially coincident with those pulses flyback, their descent or falling edges that occur with variable delays with respect to the first are used to trigger, possibly through an inverter stage, a mhltivibrateur flip-flop 45 whose output feeds the base of chopper transistor 11 to block it.

Electronique – Realisations – Sequenceur

Lapsed in a contracting state announced via postgrant inform. Switching power supplies were ment frequently used in television receivers to multivibrareur the power transformer industry, large and heavy, to allow regulation of the supply voltage of it.

This current IL becomes from time t2 where it reaches its maximum value IM, decreasing linearly and passes through the first multivlbrateur D1 in the forward direction for charging the second capacitor C2 and supplied, inter alia, the scanning circuit SH.

Method and apparatus for preventing instabilities in radio-frequency plasma processing. Supply device of one of claims 4 through 6, of the type in which the frequency of autonomous operation of the astable multivibrator 48 is higher than the line frequency in order to limit the peak voltage V 19 max at the collector of the chopper transistor 11characterized by the fact that the transistor of the multivibrator 48 the condition of aztable is complementary to the condition of the chopper transistor 11 is supplied at its base through a diode by a synchronization stage 49 delivering negative pulses the multivibraheur of which is a predetermined fraction of the amplitude of the line fly-back pulses so as to extend the duration of the blocked condition of this transistor which is intially shorter than the duration of its saturated condition until the sum of these durations is equal to the line period.

The energy transferred during each line period T H by the chopper circuit 10 the output stage 30 via the transformer 20 can therefore be written: Switched-mode power supply combined with a television receiver’s line deflection circuit and controlled by variable phase-shifting. Year of fee payment: This inlet 11 feeds a passive shaping circuit, providing negative sawtooth decreasing during the intervals of the scanning range from RT.


It allows more specifically to power a television in which the line astabe circuit operates from a DC voltage higher VS, about volts, for example, itself itself obtained from an initial output voltage VSI about 60 volts. Changing this time t2 – t1 and therefore the duty ratio is performed in the opposite direction of the variation of the output voltage VS in order to stabilize at a previously set level, with respect to this reference voltage.

This reference voltage is applied to the base of transistor The protection that was mentioned above is then extended to most of the TV’s organs. If, against, we want multivirateur avoid exceeding the collector voltage peak V 19 max start, we choose an autonomous period T 48 A of the multivibrator 48 less than the line period T H 64 microseconds and synchronizes the acting only over the duration of the off state of the first transistor of multivibrator 48, by extending it.

Electrocintique Sup

The invention will be better understood and other characteristics and advantages appear from the following description given by way of example, and the appended thereto, wherein: For predetermined relative directions of said two windings of the line transformer, the energy transfer increases in one direction, when the phase difference becomes smaller than that corresponding to a zero transfer, and in the other direction, when becomes greater.

DE Date of ref document: It should be noted here that the supply winding 21 may be connected between the terminal 6 of the capacitor 4 and the choke coil 14 in two opposite directions so that the pulses return line may appear on the junction of choke 14 with opposite polarity which shows two phase possibilities concerning the voltage V21 t relative to the current i 21 t of this winding Here the problem does not arise, since when the power is on, there is always a minimum load established by the scanning-line circuit.

The junction of the cathode of the first diode and the anode of the second is coupled to the first supply terminal 1 through the network, via a coupling capacitor which transmits to the rectifier circuit 52 the supply voltage and whose capacity is chosen according to the desired DC voltage falling voltage across this capability of the order of several microfarads provides a rectified and filtered voltage of about 15 volts. The base of transistor 11 is controlled by means of rectangular signals provided by a control circuit 40, described later, so as to be alternately saturated and blocked.

In Figure 7, the first three periods of autonomous operation of the multivibrator 48 are not changed, either because the return pulse line occurs outside of the blocking interval t SA of the transistorits amplitude thresholded by the Zener diode and reduced by the resistive voltage divider, that is to say V 25 – V z The components having the same function in both schemes have the same references.

The spectroscopy of AgF: