H
The CRT for the 1493, 1793 and 2093 monitors have a 90° deflection angle. The 1993 incorporates 100° while the 2793 CRT has 110° and the 3693 has 111° deflection angles. These picture tubes have integral implosion protection and a EHT of 25KV.
H1
The Vertical Dynamic Focus amplifies the parabolic waveform across the vertical coupling capacitor from about
H2
The Horizontal Dynamic Focus amplifies the parabolic waveform across the horizontal coupling capacitor, using a transformer to produce
I
Blanking is accomplished by setting the gain of the interface IC to zero during blank time. The Horizontal Blanking pulse is generated by amplifying the flyback pulse. The Vertical Blanking pulse is started by the vertical oscillator one shot and ended by the counter in the auto bias IC via the "bias out" pulse. The Master Gain control, located on the remote PCB, sets the gain of the video signal when blanking is not active. The Beam Current Limiter circuit, which is designed to keep the FBT from overloading, will reduce the video gain if the maximum average beam current is exceeded. Also, the beam current is reduced if the FBT approaches maximum operating temperature.
J
The Sync Interface can accept separate or composite sync. Two comparators are used to receive sync, one for vertical sync and the other for horizontal sync. Resistor dividers are used to protect the comparator IC from over voltage damage. For customers who do not require interlace, an additional vertical sync stabilization circuit is included. This circuit synchronizes the vertical sync to the horizontal cycle.
K
The Vertical Oscillator generates the vertical free running frequency when no vertical sync is present. When sync is applied, the vertical oscillator synchronizes to the leading edge of the sync pulse.
L
The Vertical Control & Output circuit consists of:
1.One shot.
2.Ramp generator.
3.Vertical drive.
4.Vertical output.
11
