Axis 670 Manual de instrucciones descargar pdf (Pagina 8)

attained the proper level. Proper gauging of wire and power supply sizing should be considered

during the design integration ofthe system.

**Note: If the power supply cannot support the amount of current drawn by the servo board, the

servo board will automatically shut down. This is part of

the

normal

"turn-off'

circuitry of the

board. Do not use power supplies that "fold-back" in voltage when too much current is drawn.

This could result in a continuous fault cycling that could damage the scanner/servo combination.

Shown below is the pinout for

input power connector:

= + Supply Voltage

= +Supply Voltage Retiim

== -Supply Voltage Retum

Pin4 = -Supply Voltage

3.4. Position Demodulator

A differential current signal is obtained from the position detector within the scanner. The

amplitude of this signal is modulated by the scanner output shaft angle or "position". Referring

to tiie 670 schematic, la and lb are converted to voltages, Va and Vb, by the two transimpedance

amplifiers in the position demodulator section. The position output voltage, Vp, is then detected

as the difference of these two voltages. This signal is then sent on to the tuning section of the

amplifier and to the outside world via a buffer amplifier. This buffering allows the user to

monitor the scarmer's position without fear that the measurement device will affect the position

signal. The position signal is available at J4.2 or TPl. Use TP2 or W7.2 for the retum. The scale

factor for this output is

0.500

volt/° mechanical, standard.

3.5.

AGC Circuit

The output signal of

scaimer's position detector is powered by an ACJC signal generated on the

670 board. To monitor this signal, use TP7. Use TP2 or W7.2 for the ground retum. The 670

board's ACJC circuit monitors the sum of voltages Va and Vb and forces this sum to be constant

at all times. Thus, any drift ofthe position detector is stabilized to a very high degree. Since the

angular excursion of the scanner is inversely proportional to Vagc, this circuit is also used to

adjust the position detector scale factor or the 'Tosition Output Scale Factor". However, this

should only be done when retuning the original scanner, or when matching a new scanner to the

servo board. The scaimer's scale factor should never need readjusting during its lifetime.

Changing the position output scale factor in this manner directiy affects the system's loop gain.

Tuming Rl3 to set a scanner's field size will result in changed dynamic performance. Refer to

section 6.0. for adjusting the output scale factor. ***Caution: Misadjustment of R13 could

result in damage to the scanner. Refer to section 6.0 before adjustments are made.

The apparent linearity ofthe position detector is affected by component tolerancing ofthe servo

board's position demodulator and by other factors within the scanner. These nonlinearities can

1 2 3 4 5 6 7 8 9 10 11 12 13 ... 67 68

Comentarios a estos manuales

Sin comentarios

Axis 670 Manual de instrucciones Pagina 8

Comentarios a estos manuales

Relacionado con productos y manuales para Impresión y escaneo Axis 670