2 Positive Going Analog Mode

In the positive analog mode, a bias current of .6mA flows to the input pin 2. This current is set by resistor I 261 I at the +Analog Enable input pin 11. The .6mA produces a voltage, across the parallel resistance of the game and I 288 I plus resistor 1278 I , at pin 2. If the external source resistance is 75 ohms, the black level voltage at pin 2 is .18V for 15KHz and .07 V for the 31KHz. The black level voltage is set by resistor divider I 223I & I 226 I to compensate for the bias current...

3

Monitors with vertical deflection current which exceeds 2.2 Ap-p cannot be driven directly by the LA7838 vertical deflection IC. The vertical booster amplifier circuit reduces the output current of the LA7838 by amplifying the vertical deflection current. The LA7838 is mounted on the vertical booster amplifier circuit board to allow the boosters circuit to be inserted at the output of the LA7838.

5

In the + analog AC coupled mode, the video black level is set by a clamp circuit which is active during the first part of horizontal sync. For this circuit to work properly, the incoming video must be at the black level voltage when horizontal sync starts and remain blanked for at least 4.5uS. The clamp circuit is dependent on the polarity of incoming horizontal sync. For separate horizontal sync, the sync polarity should be positive. For composite sync, and positive going horizontal sync...

About This Manual

This manual is specifically written to aid the service technician, repairing CERONIX Models 1493, 1793, 1993, 2093, 2793, and 3693 color monitors. To understand how the Monitor works, it is best to know what each circuit does and how each circuit relates to the other circuits. The Block Diagram is presented in a simplified view and a comprehensive view to accomplish the goal of understanding the whole unit. Once the general picture is clear, the complexity of each circuit will be easier to...

Attach The Grounding Strap First

With the degaussing coil leads centered on the bottom of the CRT, FORM THE COIL to avoid the remote control board. INSTALL A WIRE TIE through INSTALL A WIRE TIE through the top hole in the left CRT ear. the top hole in the right CRT ear. INSTALL WIRE TIES through the bottom hole in the left CRT ear. INSTALL WIRE TIES through the bottom hole, with the grounding strap spring, in the right CRT ear. Degaussing Coil & Grounding Strap Attachment Specification. For The Model 1793, 1993, 2093 Video...

Crt Auto Bias And Auto Bright Circuit Description

The beam current feedback circuit uses a PNP video transistor 954 to direct most of the beam current to the auto bias circuit while passing the voltage waveform, from the video amplifiers to the CRT cathodes. Diode I 958 I and capacitor I 956 I insure that no video waveform distortion occurs. An additional benefit of this circuit is that it protects the video amplifiers from the destructive arc energy. Resistors I 948 I and I 955 I divide energy due to CRT arcing, between the video amplifier...

Crt Auto Bias Vertical Sync

The vertical oscillator one shot (LA7851 pin 16) supplies the start timing for the auto bias vertical sync. This signal is conducted to the emitter of 379 by jumper 089 . The base of 379 is connected to the retrace boost pulse by resistor divider 3831 and 384 . Combining these signals in this way produces a collector waveform which has the vertical oscillator one shot timing and is dependent on the retrace boost pulse. For the 15KHz case, transistor 100 inverts the vertical oscillator one shot...

Dynamic Focus Circuit Function And Circuit Description

The dual focus CRTs require a waveform on the 2 focus grid. This voltage waveform is dependent on the position of the beam on the CRT. The lowest voltage part of the waveform is in the center of the screen and the highest voltage part of the waveform is at the corners of the screen. The dual focus CRTs require a waveform on the 2 focus grid. This voltage waveform is dependent on the position of the beam on the CRT. The lowest voltage part of the waveform is in the center of the screen and the...

Equipment setup for trouble shooting the Iso Xfr75W Iso Xfr100W Isolation Transformers

Easter Sunday School Activities

SAFETY FIRST Use only one hand when working on a powered up ISO XFR-75W, ISO XFR-100W to avoid electrical shock. Always wear safety glasses when working on powered up electronic equipment. Note When using this isolation supply for working on monitors, it is important to have some resistance (10MQ or less) to ground. An insulated monitor connected to a insulated power supply may attain a high static voltage. When this voltage discharges through the ISO XFR-75W, ISO XFR-100W control circuit, the...

Installationsanweisungen fr die XX93 Monitore

Ein 3 Ampere-T Sicherung (f r die degaussing-Str mung) und ein 75 VA Isoliertransformator ist die Minimum-Forderung f r benutzen unseren Monitoren in einem Produkt. 3. Schlie en Sie den Monitor F r Details, Folgen Sie den Installation-Anweisungen, im Gehause an. Vom Lieferanten der Antriebelektronik. 4. Verbinden Sie den Gr ne Gelben Schutzleiter zum Erdung anschlu auf dem Gehause. Dieser Draht ist verbunden zur der Erdung-Schraube auf dem Monitor-Chassis, und wird hinter der...

Isolation Transformers

The ISO XFR-75W -100W MUST be grounded by mounting on a grounded, conductive surface via at least two screws. WARNING Mains power and ground connections must be made before power is applied to the ISO XFR-75W or the ISO XFR-100W Isolation Transformers. WARNING FOR CONTINUED SAFETY, REPLACE SAFETY CRITICAL COMPONENTS ONLY WITH MANUFACTURER'S RECOMMENDED PARTS (REFER TO SERVICE LITERATURE). AVIS POUR MAINTENIR LE DEGRE DE SECURITE DE L'APPAREIL NE REMPLACER LES COMPOSANTS DONT LE FONCTIONNEMENT...

Simplified Video Amplifier Circuit

The video amplifier drive circuit is built on a ceramic substrate which is a good heat sink. The printed resistors and conductors are small and have precise geometries which output a faithful reproduction of the input signal with good high frequency response and low overshoot. The NE592 is a 120MHz emitter coupled differential amplifier which is connected to a push pull output stage. This output stage has a low bias current of 3mA and a bandwidth of 25MHz. Although at 25MHz, the output stage...

Stromkreisfunktion Beschreibung

Die grundlegende Funktion des XFR75W und des XFR100W ist, die Zeile Energie f r die ben tigenden Monitoren und Lokalisierung Transformator zu lokalisieren. Der Transformator wird entworfen, um einen niedrigen Durchsickernflusswert zu haben, der erlaubt, da er nah an der CRT eingehangen wird. T vollenden den niedrigen Durchsickernflu , hat der Transformator zwei Sets der Prim r- und Sekund rspulen, die an einem ge nderten Ringk rperartkern eingehangen werden. Der ideale Transformator w rde ein...

Tc Z

The high voltage in the CRT, through an arc, can be conducted to any tube socket connection on the video board. To reduce the danger of these arcs causing component failure, a number of arc current paths are provided. The tube socket has integral spark gaps which conduct arc current to the tube ground (aquadag). through dissipation resistor 882 . The clamping voltage of the spark gaps to the cathodes and G1 is about 1.5KV. The peak arc current to the video amplifier outputs is limited by...

Vertical And Horizontal Sync Circuit Description

Composite sync or separate vertical and horizontal sync are buffered by two comparators in the sync interface circuit. A vertical sync synchronization circuit is used to insure a stable raster and functions as a sync separator. The synchronization circuit is bypassed, for interlaced vertical sync, because this circuit rejects the half horizontal line time variation used to generate the interlaced vertical raster.

Vorrichtungen haben zum Lsen von Problemen mit dem 75W und dem 100W Isolierung Transformatoren benutzt

SICHERHEIT ZUERST Um elektrischen Shock zu vermeiden, benutzen Sie nur eine Hand beim Arbeiten auf einem angeschaltenen Transformator 75W oder 100W. Tragen Sie immer Sicherheitsgl ser beim Arbeiten auf angeschaltener elektronischer Ausr stung. Anmerkung Beim Benutzen dieser Isolierung Versorgung von Monitoren dem Bearbeiten zu, ist es wichtig, irgendeinen Widerstand zu haben, (10 Meg.Q oder kleiner) zu erden. Ein Isoliermonitor, der an eine Isolierenergie kann angleschlossen wird eine hohe...

Wire Routing Instructions

Attach the protective earth, Fold remote cable to clear green yellow, ground wire. CRT and add wire tie. Rout G2 wire around CRT socket, shorten with loop, and add wire tie. Plug in video board. Fold video flat cable to avoid contacting the metal frame. Secure fold with a wire tie. Shorten focus wire and add wire tie. Finished assembly with the different voltage type wires not touching each other. Make solder connection CA when using these C PRAs for replacement parts on the XX92 product line....

Circuit Function Description

The basic function of the ISO XFR-75W and ISO XFR-100W is to isolate the line power for monitors requiring an isolation transformer. The transformer is designed to have a low leakage flux value which allows it to be mounted close to the CRT. To accomplish the low leakage flux, the transformer has two sets of primary and secondary coils mounted on a modified toroid type core. The ideal transformer would be a toroid but this type transformer is expensive because it is difficult to wind. A relay...

Ceronix Model 1793 Replacement

The CRT Auto Bias IC is a combination of digital and analog circuitry. The digital part is a counter and control logic which steps the analog circuits through a sequence of sample and hold conditions. The analog part uses a transconductance amplifier to control the voltage on a 10uF capacitor (one per gun). This voltage is buffered and sent to the video amplifiers as the bias voltage. In monitors without CRT auto bias, this voltage is adjusted manually using a setup procedure to set the color...

Horizontal Raster Width Control Circuit Description

The purpose of the horizontal width control is to 1. Provide a convenient means for adjusting the horizontal raster size. 2. Correct pincushion distortion in the vertical axis. 3. Correct horizontal raster distortion caused by periods of high beam current. The horizontal width control circuit is comprised of two main parts The control circuit and the diode modulator (DM). The control circuit combines four signals in the monitor to produce the width control circuit. These signals are 1....

High Pot Tester

The MONITOR is connected to the enclosure ground via the signal cable, monitor support hardware, and the protective earth ground wire. The chassis ground must be connected to earth ground. All the large accessible metal parts are connected to ground. Highpot, F r Schock Gefahren, StromkreisBeschreibung. F r die Modelle 1493,1793,1993,2093,2793, und 3693 videomonitoren. Es ist die Verantwortung der Firma, die den Ceronix Monitor in dort system benutzt, sich zu vergewissern, da kein Schock...

Simplified Power Supply Circuit Description

The FET drive circuit avoids this problem by sensing flyback diode conduction. If the flyback diode conduction is sensed, the low current start mode is selected. This mode turns the FET on, to a current of .1A, for not more than 4uS. If before or during the low current FET on time, the flyback diode breaks free, and the FET drain voltage goes down, the flyback diode voltage comparator will signal the regulator to permit the FET to be turned on for a full power cycle. The cycle after the last...

Ceronix 2793 Service Manual

SAFETY FIRST Use only one hand when working on a powered up monitor to avoid electrical shock. Many of the failures that cause burnt components and boards are eliminated by the load sensitive switching mode power supply in the CERONIX monitor. This feature can cause problems with servicing the monitor if the proper trouble shooting approach is not used. The equipment setup, shown here, is necessary for efficient trouble shooting of the CERONIX monitors....

Instructions dinstallation des crans XX93

Un fusible fusion lente de 3 amp pour le courant du champ magn tique d'adjustement et un transformateur d'isolation de 75 VA sont le minimum requis pour utiliser nos crans dans un produit. o t ii i j Se r f rer aux instructions d'installation foumies par le fabriquant 3. Installer l cran dans son carter. , , , , ,,, du syst me pour les d tails de montage de l cran dans le carter. 4. Relier le fil de terre vert jaune la prise de terre sur le carter. Ce cable est reli la vis de terre situ e...

Installation Instructions For The XX93 Monitors

A 3 amp slow blow fuse for the degaussing current and a 75 VA isolation transformer are the minimum requirements for using our monitor in a product. 3. Install the monitor in the enclosure. Refer to the installation instructions supplied by the system manufacturer for details of mounting the monitor in the enclosure. 4. Connect the green yellow ground wire to the earth ground connection on the enclosure. This wire is connected to the ground screw, located on the monitor chassis behind the...

Table Of Contents

Block Diagram Crt Monitor

Video Amplifier Circuit, Function, Video Amplifier Circuit Description and Video Board Power Supply and Arc Protect CRT Auto Bias and Auto Bright Circuit, Function, CRT Auto Bias, Auto Bright, and Vertical Sync Delay Circuit Description 72 CRT Auto Bias and Auto Bright Monitor, Block Diagram Blanking, Master Gain, and Fault Circuit, Function, Blanking, Master Gain, and Fault Circuit Blanking, Master Gain, Beam Limiter, and Fault Vertical and Horizontal Sync Circuit Vertical Deflection Circuit...

2 Year Limited Warranty

This product is warranted by CERONIX to be free of defects in material and workmanship for a period of two years from the date of purchase. All parts and labor are free of charge during the warranty period. This warranty does not cover mechanical breakage due to physical abuse. It is the customer's responsibility for shipping the defective unit to and from CERONIX or one of the authorized service centers for repair. Please attach a note describing the problem. CERONIX Inc. 13350 New Airport...