alteration monitors EGA (CGA) in VGA (SVGA)

At alteration of monitors EGA and CGA in VGA it is necessary to decide(solve) two tasks:
Processing of video signal and translation of display from frequency 15KHz 
up to 31 (and in SVGA and 37) KHz.

First is caused by a digital input(entrance), instead of analog, as in VGA.
Second - coordination of capacities in the target cascade Lower case

first (as will allow at the first stage already to see "narrow"
Need to replace EGA the plug on 15-th pin three-row from VGA
Further - to copy on pathes a part of the monitor from an input(entrance) up to the panel tube,
As a rule on an input(entrance) costs(stands) PLM and inverter - them to remove(take off) from a payment.
As to clean(remove) all resistors and capacitors to them going,
connect to three inputs(entrances) (former rgb) resistors 75 Ohm, other end them on
And input(entrance) "r g b " to connect to ground (and in the plug too).

The target cascade as a rule is made under the following circuit:
The target transistor (2) under the circuit with general(common) base, before it (1) - with general(common)
Input(entrance) with the resistor 75 Ohm, going on ground to submit on base first
The transistor.
In emmiter it there should be a circuit - resistor (300 Ohm... 30 Ohm) on ground, and
parralel to it(him) the condenser (1000 pF... 300 pF).
By the resistor further to expose the necessary contrast, and condenser
Base (1) as to submit through the resistor (300 Ohm... 1K) on +5V,
Exact face value to check up in DOS program "ChekIt v3.0" - it is necessary will be convinced in видемости all
Gradation In 13-th a mode (256 colours).

Most simple the amplifier turns out (on base) under such circuit:

For synchronization on lines and staff to collect this circuit (7486 as a rule
Is On the circuit)

If these conclusions (6 and 8) to submit on 561KP1 (4052), will be two 
commutators on These 4 regim by one size on vertical, another 600 lines to change
The circuit output and to add power supply if necessary.

The note:
The same circuit can be put at a start in SVGA monitors them idenif., 768
not work, but on 14 " it not need

But is possible instead of 561KP1(4052) use already available circuits of change of 
the size on Verticals and switchings from a mode CGA in EGA in monitors EGA.

For automatic change size on vertical it is possible use and The circuit
From monitor (display) "casper" (send my good the man, senks to him):

Now monitor should show normally, but only in two narrow screens
We pass to displays.
To close (short circuit) base and emmiter of the target lower case transistor by the 
crosspiece ( In the circuit with separate generators high and development(display) - at both
On base buffer of the transistor to connect oscillograf.

To find the specifying generator of lines, about him(it) frecuency the condenser (capacitor),
For example - on reaction of target frequency to an easy contact by his(its) finger.
To replace it(him) (with high temperatur stable) with the condenser (capacitor) with smaller face value.
The control of frequency - there where and oscillograf,
It is necessary made of frequency 31 KHz.
Now to specify a type and parameters of the lower case transistor.
His(its) voltage should be about 1500V, capacity (power)from 30W, frequency from 3-th MHz.
As the presence built - in dempher of the diode is desirable,
Not bad have shown itself transistors 2SC3883, BU2508, BU2525, 2SC4769.
In very old monitors is necessary to replace regular transistor on one of
Given ( Or them(him,it) similar).
After replacement it is possible to clean(remove) the crosspiece, to include in break of a feed(meal) of display
(55... 80V) resistor such as PEV (nicel-hrom) on 10... 20W by face value 20 Ohm.
To include the monitor.
Is possible(probable) narrou, dim picture.
To find out, whether is rool up in horisontal it (those actual width screen less
If is - the reduction of face value of the condenser parrallel is required
To target(day off)
To the transistor (and the condenser (capacitor) should be on 1600V such as K78-2 and other).
Then is necessary short circuit coil regulating size of lines, (she(it) costs(~is necessary,stands) in
Break )
As it is necessary to wind in half coil of a regulator linest.
Take into account - she(it) polar!
If after connect back linest sharply will worsen - to turn her(it).
General(common) linest on a horizontal to reduce by selection of the condenser worth
Between a "cold" conclusion horisontal coil and ground.
As a rule it is necessary it(him) considerably to reduce, (with reduction is stretched(dragged out)
The centre)
Typically with 2-3mkF up to 1-0.3 mkF.

Have achieved equal picture, but is narrow.
It is necessary to lift a pressure(voltage) of a feed(meal).

In number(line,beside) of models is two feeds(meals) - one for lines, another for
If second in borders 80-100в, it(him) to connect instead of 55в,
It is necessary to replace the diode in power supply on this line with one more powerful!
( Such as KD226 (rus) will approach)
If is not present suitable, or it 150V and more, is necessary add 20-30 coils
By wire such as PEL (rus) 0.3, and to include them in phase with a winding on 55V.
After that the size and brightness are normalized, working the monitor on a subject
corrupt or dead of lower case unit,  sometimes there costs(stands) very small on the area
If the overheating is - to replace a radiator with another - with the greater area.

The mode in 600 lines is rather easy for receiving in ега monitors, there is incorporated
Switching of frequency 15/21 KHz (and in a primary winding lower case
The transformer
Two windings) are switched,
And if to use a mode 15 Khz as 31, that that was 21 - will be Normally
To work on frequency 37 KHz (600 lines at 60гц personnel)
After assembly working the monitor _no departing from his_
Such as in what strategy longing, what in case of that not so - at once
To switch off and to find out, what not so (for example - on excessive heating).

Only then it is possible to remove(take off) the restrictive resistor and to close a place of breakage

The circuit Polish EGA-display CM322: (320k) Principle of alteration CM322 (russian) (not mine, not so optimum, I can recommend Only for acquaintance, as is useful schemes of an arrangement tuning Resistors on a payment): cm322up.rar (8k) PRINCIPLE of ALTERATION of DEVELOPMENT(DISPLAYS) CM322: In power supply (PS) of a winding on the transformer so to redistribute, what 15V, 6.3V, 150V And 55V Have remained as is, and 110V to lower up to 90V There 15V in two windings in parralel, with them consistently all others ( Except for 150V and 6V) These parralel of a winding to divide(share), 15V to make separately, and it is consecutive Former 55 To include a piece from 15V Then 15V will be kept, 55V too (at first have taken away, then have added 15V), and 110V Will be lowered on 15V By these 90V and to have horisontal+high+video ampl (the diode in a circuit 90V More powerfully to put, and that there fine that that costs(stands), and it is necessary on Amper - KD226 For example) 150V are not necessary (those it is possible the diode with capacitor to remove(take off)) - on the plug to close 90 and 150V Then on the high-voltage cascade will go 90V instead of 150V Further under the circuit of the monitor to alter: Element on 74ls86 (555LP5) to alter according to the typical circuit Alterations EGA-VGA, only personnel part use everything, and lower case - only connect Polarity, and free element to use as the inverter, through him(it) and To pass(miss) Output(exit) of installation of polarity on the circuit of synchronization. From an output(exit) 74ls86 a personnel pulse to submit on the circuit of personnel synchronization Directly, Those to clean(remove) the resistor in base, transitive resistor закоротить, and to submit on "-" electrolit of the capacitor (in a result to clean(remove) inversion) High-voltage circuit to make as standard - those all эмиттерную a circuit ( Resistors up to ground, кондеры there, transistor on large radiator on To middle of a payment) to clean(remove) and short circuit (with the account transformer in base of the transistor Target(day off)) Condenser in circuit collector - ground is necessary after to reduce (compromiss between high voltage+focus screen - the size on horizon, is typical 3300pFx1600v) BUT11 To rearrange on lateral aluminiem radiator (about mica do not overlook(forget)) In development(display) - cut a path of a feed(meal) 55V, what there (in a feed(meal) Development(display)) 90V To insert To clean(remove) a circuit with triac and additional condensers of switching Modes EGA-VGA The transistor 2SC3888 is possible to not change, and to leave on the same radiator The condenser in k-e to change in a place (if screen the condenser is turned) Consecutive With horisontal coil - on liner (if is compressed in centre - to reduce) - typically 0.47мкф in Result Currents of consumption: High-voltage part - 150-200mA Development(display) - 150-180mA At first to adjust previously development(display) (orient - current of consumption And presence horizontal impuls, going on the circuit regulator of the size on horizon) The ambassador a circuit high Also DO NOT OVERLOOK(FORGET) ABOUT RESTRICTIVE RESISTORS WHILE THERE IS an ADJUSTMENT!

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