GLENTEK Inc. 208 Standard Street, El Segundo, California 90245, U.S.A. (310) 322-3026
13
CHAPTER THREE: PERSONALITY PREAMP CARD
3.1 INTRODUCTION TO THE PERSONALITY PREAMP CARD:
The Personality Preamp card is a modular plug-in card that comes in two versions: velocity mode and cur-
rent mode. Schematic and board-assembly prints for these cards are found in Appendix C, drawing numbers
4597-7010, 4597-7012, 4597-5010, and 4597-5012, and will be referred to in the following description.
The Personality card contains the main high-gain preamp with all associated system alignment adjust
ments. This card greatly enhances system trouble shooting and repair. If an amplifier should fail, simply re-
move the Personality card (which has all of the original system constants adjusted in) and re-place it on a
spare amplifier. This eliminates system realignment when changing out amplifiers. Also, a motor-tach-load may
be aligned at the factory and then just the Personality card sent to the field for system test.
3.1.1 VELOCITY-MODE PERSONALITY PREAMP CARD:
The Velocity-Mode Preamp card contains the main high-gain preamp with all the associated system
alignment adjustments to close a velocity loop using a D.C. tachometer for velocity feedback (Refer to
Appendix C, drawings 4597-7010 and 4597-7012).
3.1.2 CURRENT- MODE PERSONALITY PREAMP CARD:
The Current-Mode Personality card contains all the system alignment adjustments to control a current-
mode amplifier (Refer to Appendix C, drawings 4597-5110 and 4597-5112).
3.2 DESCRIPTION OF OPTIONS AND ADJUSTMENTS:
The Personality Preamp card is a small printed-circuit card (2.7” x 2.3”) standing on nine pins (0.6” long)
that mate with appropriate sockets on the amplifier control board.
The Personality card is most often used to close a velocity loop by using a DC tachometer for velocity feed
back. However, the high-gain, summing amplifier can be bypassed providing an input directly to the current-
loop amplifier (Current-Mode option). If the Current-Mode (CM) option is specified, the committed Current-
Mode Personality Preamp card will be supplied.
3.2.1 POTENTIOMETER ADJUSTMENTS:
The following is a description of the potentiometer adjustments used for the two modes of operation.
Please refer to Chapter Six on Start Up and Adjustment Procedures for a detailed description of how to set
these potentiometers.
VELOCITY MODE:
(Refer to Appendix C, drawings 4597-7010 and 4597-7012)
R12
Signal-Gain
potentiometer sets the input voltage to output RPM required by your system for the single-ended
input (e.g. 10 volt input = 2000 RPM).
R13
Auxiliary Signal-Gain
potentiometer sets the input voltage to output RPM required by your system for the dif-
ferential signal input (e.g. 10 volt input = 2000 RPM).
R14
Tachometer-Gain
potentiometer sets the amount of tach’ signal required by your system. Use in conjunction
with the Compensation potentiometer, R16, to adjust the system bandwidth.
R15
Balance
potentiometer is used to null out any DC offset in the amplifier (e.g. 0 volt input = 0 RPM).
R16
Compensation
potentiometer sets the amount of bandwidth (frequency response) required by your system.
Use in conjunction with the Tachometer-Gain potentiometer, R14, to adjust the system bandwidth.
R17
Current-Limit
potentiometer sets the maximum acceleration and deceleration current.
CHAPTER THREE: PERSONALITY PREAMP CARD
