DE1920134A1 - Protection circuit for cathode ray tubes - Google Patents

Description

Patent attorney

Dipl.-Ing. Walter Jackisch
Stuttgart N, Menzeisüaße 40 1 9 2 0 T 3

April 18, 1969

A 31 100 - sz

18, Ruo de la Felicite
.Parie 17 / France

Protection circuit for cathode ray tubes

The invention relates to a protective circuit for cathode ray tubes « especially in Traneistor-Fernaeheapflngem, sur Securing the cathode ray tube against stopping the beam deflection. In particular, there is consensus in the field of application of the invention Color as well as black and white television receivers can be considered.

The protective circuit according to the invention is characterized here mainly by means of converting at least one deflection signal into a DC control voltage sur control of a transistor, which in turn controls the radiation and / or controls the anode feed of the cathode ray tube to be protected

The invention is illustrated in more detail with reference to the in the drawings Execution example explains «Bierin selgt

rig. 1 the circuit of a stabilized supply voltage source for use in the protective circuit according to the invention,

Fig. "2 a protective circuit according to the invention with monitoring of the horizontal and vertical deflection"

1320134 - ζ · -

including the corresponding monitoring transistors ,

3 shows the subsequent section of the protection circuit ges & ss Flg. 2 of the surge transistors (nochaals ainsehllesslioh) to sur Gltterepeisuag der s ^ oenracdieAdea bsw · su echot xeadcn cathode ray tube and

Fig «4 a further ·» section, the Sohutssohaltung goals «Fig · 2 _f and swsr from the monitoring ·" transistors to the anode feeding of the monitoring stirrer ·

Fig. 1 shows an oohvoltage stabilized by a Sener diode source of a kind known per se »the i» example! «!! is shown for the sake of completeness and possibly by other known ones Facilities of this type can be replaced

Aa B input 9 of the circuit according to FIG. 1 becomes «ine output voltage suge £ ilhns »while the Scnaltua ^ r a» output Jl by; the lener diode S stabilized supply voltage sur Postponement provides · for regulation of the output voltage can $ n a further input 82 of the circuit aaon? i9> 1 a control voltage veu »output on ·· compare ·» be shown · In all cases, "one more" can be connected to one input S3 of the circuit the following is a detailed reverse voltage.

The circuit according to Fig. % I *% in Figs. 3 and 4 is only _{indicated as "Block I A} , Z ₈ UsV" Zg and other "aft ors" can be achieved through suitable circuits. "" of the function * J, b · in feesu? on you «

BAD ORIQWAL

-3- 192013A

or input voltages and the output voltage generated from them serve the same purpose ₀

-In Fig. 2 1st a supply source I _ft with an output voltage of 4 * 35 V at output Sl of the horizontal deflection and a further supply source I _ß with a voltage of +12 V is applied to the output S for the vertical deflection indicated.

At the connection B of the circuit according to FIG. 2, one does not shown, working with the line frequency a square deflection pulse train supplied »which after passing through an integration amplifier Tl in the form of a saw tooth pulse train Via a transformer TR to the terminal 2 of a horizontal deflection device DVl and D72 of the cathode ray tube to be protected Is fed "at exit 3 of the deflection device the SM tooth pulses are generated by means of an integrating capacitor Cl transformed into parabolic curved pulses of the type indicated

The subsequent series capacitor C2 allows the AC component ^ by this pulse sequence, which is then rectified by a diode D · A ansohllessendes filter element with filter capacitor C3 generates therefrom a DC control voltage corresponding to the input "d _o h. the base of a transistor T2 connected to ground via a Zenerdlode on the emitter side.

At the input B 'of the circuit according to FIG «2 a sawtooth · pulsfo-lge is (also not shown) of an operating with the frame frequency oscillator supplied and, after amplification in a transistor Tl' via a transformer TR * directly the Vertikalablenkvorrichtung DVL ^1, DV "fed" via a chain circuit at output 3 of the

909851/1199 - «-

BATH ORIGINAL

Vertical deflection is described in the Sägesahnpulsfolge the same manner as previously described for the output of the front direction BorisontalablenJc reshaped "rectified and smoothed, and a second fiber a transistor T2 · about" sugeführt waohungstransistor T3 *. Oils elements of this "broad chain management" between output 3 and transistor T2 * are rewarded with Cl ¹ , C2 ", Dl * and C3.

The collectors of the two monitoring transistors T3 and T3 ¹ are connected to each other at circuit point H , the latter appearing again in the left part of the circuit section according to FIg ₉ 3 · The two monitoring translators are switched on the emitter side via resistors to Hasse while from circuit point Ji the supply of the grid G of the cathode ray tube TO is controlled by both monitoring transistors · As long as the signals present in normal operation reach the bases of the monitoring transistors T3 and T3 *, these remain fed · If, however, one of the two signals is fed via the chain circuit described above If the horizontal and vertical deflection fails, a negative voltage occurs in the grid 6 of the cathode ray tube "so that the cathode ray of the tube is suppressed or kept away from the screen"

The food source I _c in the maintenance section according to Pig. 4 provides on output 81 again a DC voltage of 35 V, while the input of S3 is connected to the Sohaltungspunkt M of the circuit described above · If now one of the two Eingangesignale the monitor transistors T3 bsw · T3 * fails "so the input 82 of the Spe & sequelle I _c switched to ground potential, which results in a blocking of the anode memory of the cathode frame cord.

909851/1199

BATH

In the illustrated circuit according to the invention the horizontal deflection signal bsw. the vertical deflection signal in a DC control voltage stubbornly controlling one transistor each implemented, which in turn bsw the beam intensity Anojfden supply of the cathode ray tube to be protected controls »It is important that these two taxes bsw. OberwaehungskanSle both for themselves and for and swar this preferably »old at the same time» he see each other · brilliant function can be used «The simultaneous Effectiveness of the two channels offers, among other things, the advantage of one increased security against failure · In this way, a Damage or impairment of the luminous layer of the picture • china · »by branding with stationary horizontal and / or vertical deflection is avoided, which is particularly important for the operation of massive televisions! trained persons) is important

900851/1199

BATH ORIGINAL

Claims (2)

Expectations * Stir 999dl Stilletand the beam deflection "gekeitnseiohnet by means' for tftiatzung least one Sblenksignals in a Glelah control voltage star controlling a ^ rimsietore" the "einereeit protection circuit for K * methods * trahlrÖh ^ s _f in particular in transistor television receivers, door securing the cathode ray «The beam intensity Knd / d4er controls the an @ denep®imi £ tf of the protective cathode ray tube · 2. Leap day according to claim 1 »thereby gekeimseicslisiet ^ 4» S> the transistor of the iiorisontalaJblenkvorrichttiAg of the cathode «beam tube« icig * «chalt * t. 3 «circuit according to JUieprtaoh 1« dadterch identified for this Transistor of the VertilialablenkTonfiohtnahm the au sohtttsefiden Cathodes «beam tube * msc ^ feechaltet 4 · So, according to Aassrtie ^ l _f d «d ^ sroh fekevjiselehnet» that the transistor with its f ^ ittes to Ifie «·« n # w &% eei & er sasis to the KonferoUipannossj meloiseai · 90985t / tt99 BATH ORIGINAL Blank page