SC-121 – Sine Servo Controller 
- Dual microprocessor design
- Digital signal sythesis and filtering
- Flexible programming
- Nonvolotile memory
- Two-channel acceleration input and control

The SC-121 Sine Servo Controller provides an economical solution to modern sinusoidal vibration testing with a remarkably convenient operator interface and dual microprocessor design. Crystal controlled digital signal synthesis and filtering insures performance found only in the best controllers available.

Selectable one or two channel acceleration feedback enables control of large head shakers, slip plates or large fixtures by averaging signals from two strategically placed accelerometers. The difference output makes transfer function determination and calibration tests as easy as running a simple sine test.

Flexible programming allows internal storage of up to three independent 1, 2, 3, or 4 level test profiles. Stored test profiles are easy to modify or replace. Digitally generated analog outputs facilitate plotting or recording test profiles.

General Specifications
Frequency Generator
Range @ resolution
(Internal switch)
2. to 6,553 Hz @ 0.1 Hz
or 4 to 10,000 Hz @ 0.2 Hz
Vibration Feedback Analysis
Accelerator range 0 to 99.9 g pk
Displacement range 0 to 2.50 in pk-pk
or 0 to 50.0 mm pk-pk
Input channels 2
Calibration inputs 10 or 100 mV/g
Variable inputs 10 or 100 mV/g +/- 20%
Sweep, Logarithmic
Modes Manual, Continuous, or
Single Sweep
Rate 0.5 to 8 octaves/min
Sweep speed resolution 0.5 octaves/min
SC-121 back view
Control Servo
Dynamic range 70 dB min
Servo Speed 3 ranges
Variable output sine voltage 0 to 2.5 V rms @ 50 ohms
Constant output sine voltage 0.60 V rms
Normalized acceleration outputs 10 mV/g @ 50 ohms (both channels)
    Log control, Log ch 2 2 Vdc/decade
    Linear difference 1.0 Vdc +/- .01 Vdc/% difference
    Log 2 Vdc/decade
Sweep/Pen lift logic TTL, low during sweep
Power 110 +/-15 Vac or 220 +/-30 Vac, 48 - 62 Hz
Temperature Range 40 - 100 deg F
Dimensions 3.5"H x 19"W x 12"D (rack mount)