SU427357A1 - DEVICE FOR DRAWING ARCS ON SCREEN ELECTRON-BEAM PIPE - Google Patents

Description

one

I The device is related to computing (engineering and technology of displaying information and can be used in systems for the exchange of graphic information between the operator and the computing machine.

 A device for the formation of circles is known by supplying a writing element with a sinusoidal voltage from two generators (according to the Lissajous figures method), which produce oscillations that are different in phase to the EO,

A disadvantage of this device is the difficulty of creating oscillators that produce oscillations of the same frequency with exactly the specified phase difference,. .

The purpose of the invention is to expand the field of application of the device and improve its parameters. For this, the number of operational amplifiers is reduced to three. These amplifiers form a generator of two sinusoidal oscillations having the same frequencies and a phase shift of 90 °. In addition, a series-connected pulse generator, a key and a counter that is connected to the control unit, amplifiers-integrators — an ip-amp amplifier — are installed in the device — an analog-to-analog converter of the initial-point position.

The drawing shows the proposed device.

The device contains

1, 2 - digital-to-analog converters setting the position of the initial drawing point; 3, 4 - integrator amplifiers; 5 - inverter amplifier} b - control unit; 7 - luminance regulator unit; 8, 9 - deflection units, beam along axis x and y, respectively; 10 - EPT; 11, 12 digital-to-analog converters of the coordinates of the reference point (center); 13 - pulse pulse generator; 14 - key; 15 is a subtracting counter for setting the arc size.

Obtaining sine waves with the required phase shift is simulated using operational amplifiers of a second-order linear differential equation

,, 3

at X (0) "Hng XCO) VH

The correspondence between the voltages U in UH and the size of the image is given by the scales

L J Uyaks Shch And | -bsJS t fml

),

In the simplest case M M M, On:

yarns on the outputs of blocks 3 (U;) and 4 (Ux are related by the following relation

I v

where k is a goat (}) transfer subscriber of the inverter 4;

Tn is the time constant of amplifier integrator 2;

{is the time constant of integrator amplifier 3.

With a ng and a k 1, the writing element moves along a circular path. The solution of equation {), which gives deflection voltages in real time (Hi 1) with regard to scale, has the form:

U, - | i cos | --- | j 3m | i

Uy - Sinf- f CQSI-.

The starting point is determined by the values of the initial conditions (X, y), aad

n n

relative to the center of the circle C x, y). The size of the radius is determined by

by the starting point and center,

To build an arc into the device, it is necessary to transfer the coordinates of the starting point (X. Coin codes

the ordinates of the center (X; y), the code of the length of the radius (R) and the cop is the magnitude of the central angle based on the drawn arc of the flow of codes into the device, which determine the 11th parameters of the arc, in the amplifiers-integrators the tension of the initial conditions is established, op | .1 This is the starting point of the tracing in relative coordinates. In the unit of regulated brightness

.f:

proportional to the values; e of the radius, and in (the counter 15 records the number determining the angular size of the arc. I At the start signal (the beginning of the tracing) the integrator amplifiers 3 and 4 are switched off from the initial ground-guessed mode to the integrated mode, and 7 produces a sinusoidal voltage,: shifted one relative to another on: 90. Simultaneously with the start of the integrator, the key 14 does not open, and the counter 15 begins to receive periodic impulses I, which subtracted from the previously set code. When zero is set in the counter 15, the control unit 6 and the entire device returns to its original state, and the drawing of the arc: ends.

When drawing a circle encoded as an arc closed, units of all bits of counter 15 are pre-set.

Subject Images

et e and

A device for drawing arcs on a cathode ray tube (ZLT) screen, containing digital-to-analog point reference coordinate transducers connected to beam deflection blocks along the X and Y axes, which are connected to a CRT connected to: a luminance control unit, which is connected to A control unit, characterized in that, in order to expand the device’s liquefaction area, it contains a series-connected pulse generator, a key and a counter, which is connected to the control unit, integrators, amplifier-inverter and if the analog-to-analog converters set the starting point slope, and the output of one of the digital-to-analog converters is the start position. To-nsi is connected to one of the inputs of the first amplification. L-integrator, the second input of which is connected to the amplifier-inverter connected to its third input and block at the timeline, which is connected to the switch, and the output of the first amplifier-integrator is connected to the X-ray unit O1 of the second amplifier - an integrator, the second input of which is connected to the output of another digital-to-analog converter, specifying the position of the initial point, and the output eio with the Y-axis deflection unit and an amplifier-inverter. J 777