MODEL 635
I. SPECIFICATIONS: AMPLIFIER MODULE
MECHANICAL:
The amplifier plug-in module is 7"H x 2"W x 12"D and weighs 16 oz.
BRIDGE EXCITATION:
Front panel adjustable, +1.0 to +15VDC with ON/OFF switch. A separate transformer-
isolated, unreg ,-24VDC power source is provided to each module.
BRIDGE CONFIGURATION:
Front panel switch selectable for 1/4 STATIC, 1/2 STATIC, 1/4 DYNAMIC, FULL and
EMF as follows:
1/4 STAT POSITION: Single active gage in a bridge configuration.
1/2 STAT POSITION: Two active gage in a bridge configuration.
1/4 DYN POSITION: Single gage in series with CV excitation source. An internal 400 ohm resistor is in series with
the gage to induce gage-voltage variations with strain.
FULL POSITION: Four externally connected active gages in bridge configuration.
EMF POSITION: For GENERAL PURPOSE differential amplifier. Input signal is applied to +S and -S terminals
of the bridge/amplifier connector.
BRIDGE COMPLETION:
Front panel toggle selects either 120 ohm or 350 ohm completion resistors in the 1/4 and 1/2
STATIC modes.
AUTO-BALANCE:
The AUTO-BALANCE function is remotely activated for all modules simultaneously with a zero-
level on a rear panel BNC or a push-button on the power supply module. Individual modules can be activated with a front
panel push-button.
Resolution: +, -2.1 mV/V of excitation at G=1000. (RTO)
A front panel LED indicates an unbalanceable condition.
AMPLIFIER CONFIGURATION:
The input signal is applied to two parallel amplifier channels, as follows:
MAIN AC/DC CHANNEL #1:
A front panel adjustable amplifier.
DC ONLY CHANNEL #2:
A fixed gain of 100, DC coupled, with a fixed frequency response of 11Hz (-3dB). Output is
rated to +, -10V at 10mA. Gains of 1, 100, 200 or 500 can be selected with a PCB jumper (J6), within a 1% tolerance.
MODE:
Front panel mode switch selects either EXTERNAL CAL, AC coupled, DC coupled, DC CAL, or ZERO, as
follows:
EXTERNAL CAL:
0 to +,-2V is connected to all of the amplifier inputs through EXT.CAL BNC at rear of rack
assembly.
AC:
The input circuit is AC coupled down to 12Hz (-3dB).
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Summary of Contents for 635-002
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