Labworks Inc. SC-121

The Labworks Inc. SC-121 is a sine servo controller purpose-built for sinusoidal vibration testing. Its dual microprocessor architecture delivers immediate control response and dynamic range of 70 dB minimum, while crystal-controlled digital signal synthesis and filtering ensure precise frequency generation and output stability across demanding test environments.

## Technical Specifications

**Frequency Generation**
• 2 to 6,553 Hz @ 0.1 Hz resolution (selectable via internal switch)
• 4 to 10,000 Hz @ 0.2 Hz resolution (selectable via internal switch)

**Vibration Feedback Analysis**
• Acceleration 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 (independently selectable for control or feedback)
• Calibration inputs: 10 or 100 mV/g
• Variable inputs: 10 or 100 mV/g ±20%

**Output Specifications**
• 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)

**Sweep and Control Parameters**
• Sweep type: Logarithmic
• Operating modes: Manual, Continuous, or Single Sweep
• Sweep rate: 0.5 to 8 octaves/min @ 0.5 octaves/min resolution
• Servo speed: 3 ranges (microprocessor optimized and frequency dependent)

**Data Outputs**
• Acceleration log control: 2 Vdc/decade
• Linear difference: 1.0 Vdc ±0.01 Vdc/% difference
• Frequency log: 2 Vdc/decade
• Sweep/pen lift logic: TTL, low during sweep

**Power and Environment**
• Input: 110 ±15 Vac or 220 ±30 Vac, 48–62 Hz
• Operating temperature: 40 to 100 °F
• Dimensions: 3.5″ H × 19″ W × 12″ D (19-inch rack mount)

## Key Features

• Dual microprocessor design for optimized servo response
• Selectable one or two-channel acceleration feedback for multi-accelerometer configurations
• Difference output enabling transfer function determination and calibration verification
• Internal non-volatile memory supporting up to three independent 1, 2, 3, or 4-level test profiles
• Intuitive operator interface minimizing setup complexity

## Typical Applications

• Large head shaker and slip plate vibration control via multi-channel signal averaging
• Sinusoidal sweep testing with programmable test profiles
• Transfer function and fixture calibration characterization

## Compatibility & Integration

The SC-121 accepts dual accelerometer inputs with configurable feedback channels, allowing integration into complex shaker test systems where multiple measurement points require simultaneous monitoring or signal combination.