Model 642 Specifications

Output

Type: Bipolar, 4-quadrant, DC current source
Current generation: Fully linear regulation with digital setting and analog control
Current range: ±70 A
Compliance voltage (DC) : ±35 V nominal
Power: 2450 W nominal
Load resistance range: 0.4 Ω to 0.6 Ω
Load inductance range: 0 to 1 H
Nominal load: 0.5 Ω, 0.5 H
Current ripple: 5 mA RMS (0.007%) at 70 A into nominal load
Current ripple frequency: Dominated by the line frequency and its harmonics
Temperature coefficient: ±15 ppm of full scale/°C
Line regulation: ±60 ppm of full scale/10% line change
Stability (1 h): 1 mA/h (after warm-up)
Stability (24 h): 5 mA/24 h (typical, dominated by temperature coefficient and line regulation)
Isolation: Differential output is optically isolated from chassis to prevent ground loops
Slew rate: 50 A/s into nominal load, 650 A/s minimum into a resistive load
Compliance voltage (AC): ±43 V nominal
Setting time: <1 s for 10% step to within 1 mA of output into nominal load
Modulation response: 0.17 Hz at ±70 A sine wave into nominal load, <0.02% THD; 10 Hz at ±10 A sine wave into nominal load, <0.10% THD
Attenuation: -0.5 dB at 10 Hz
Protection: Short circuit, line loss, low line voltage, high line voltage, output over voltage, output over current, and over temperature
Connector: Two lugs with 6.4 mm (0.25 in) holes for M6 or 0.25 in bolts

Output programming

Internal current setting

Resolution: 0.1 mA (20-bit)
Settling time: 600 ms for 1% step to within 1 mA (of internal setting)
Accuracy: ±10 mA ±0.05% of setting
Operation: Keypad, computer interface
Protection: Programmable current setting limit

Internal current ramp

Ramp rate: 0.1 mA/s to 99.999 A/s (complaince limited)
Update rate: 23.7 increments/s
Ramp segments: 5
Operation: Keypad, computer interface
Protection: Programmable ramp rate limit

External current programming

Sensitivity: 10 V/70 A
Resolution: Analog
Accuracy: ±10 mA ±1% of setting
Input resistance: 20 kΩ
Operation: Voltage program through rear panel, can be summed with internal current setting
Limits: Internally clamped at ±10.1 V and bandwidth limited at 40 Hz to protect output
Connector: Shared 15-pin D-sub

Readings

Output current

Resolution: 0.1 mA
Accuracy: ±5 mA ±0.05% of reading
Update rate: 2.5 rdg/s display, 10 rdgs/s interface

Output voltage (at supply terminals)

Resolution: 1 mV
Accuracy: ±5 mV ±0.05% of rdg
Update rate: 2.5 rdg/s display, 5 rdg/s interface

Front panel

Display type: 8-line by 40-character, graphic vacuum fluorescent module
Display readings: Output current, output voltage, and internal water temperature
Display settings: Output current and ramp rate
Display annunciators: Status and errors
LED annunciators: Fault, Compliance, Power Limit, Ramping, Remote
Audible annunciator: Errors and faults
Keypad type: 26 full-travel keys
Keypad functions: Direct access to common operations, menu driven setup
Power: White flush ON and black extended OFF push buttons

Interface

IEEE-488.2

Features: SH1, AH1, T5, L4, SR1, RL1, PP0, DC1, DT0, C0, E1
Reading rate: To 10 rdg/s
Software support: National Instruments LabVIEW™ driver (consult Lake Shore for availability)

Serial

Electrical format: RS-232C
Baud rates: 9600, 19200, 38400, 57600
Reading rate: To 10 rdg/s
Connector: 9-pin D-sub (DTE)

Output current monitor

Sensitivity: 7 V = 10 A
Accuracy: ±1% of full scale
Noise: 1 mV RMS
Source impedence: 20 Ω
Connector: Shared 15-pin D-sub

Output voltage monitor

Sensitivity: 3.5 V = 35 V
Accuracy: 1% of full scale
Noise: 1 mV RMS
Source impedence: 20 Ω
Connector: Shared 15-pin D-sub

Power supply cooling water

Remote enable input: TTL low or contact closure to enable output; jumper required if unused
Valve power output: 24 VAC at 1 A maximum, automatic or manual control
Connector: Shared 4-pin detachable terminal block
Flow switch and water valve optional

Magnet cooling water

Auxiliary

Emergency stop: Requires 1 A, 24 VAC normally closed contact closure to enable power-up; jumper required if unused
Fault output: Relay with normally open or normally closed contact, 30 VDC at 1 A
Remote enable input: TTL low or contact closure to enable output; jumper required if unused
Connector: Shared 8-pin detachable terminal block
Emergency stop and inhibit switches not included

General

Input power

Power: 5500 VA max
Voltage & current: 204/208 VAC ±10%, 13 A/phase; 220/230 VAC ±10%, 12 A/phase; 380 VAC ±10%, 7 A/phase; 400/415 VAC ±10%, 6.5 A/phase
Protection: 3-phase thermal relay with adjustable current setting; two class CC ¼ A fuses; over-voltage lockout circuit
Frequency: 50 or 60 Hz
Configuration: 3-phase delta
Connector: 4-pin terminal block
Line voltage must be specified at time of order but is field reconfigurable; cable from power supply to facility power not included

Cooling water

Flow rate: 5.7 L (1.5 gal) per min minimum
Pressure range: 34 kPa (5 PSI) to 552 kPa (80 PSI)
Pressure drop: 10 kPa (1.5 PSI) at 5.7 L (1.5 gal) per min minimum for power supply only
Temperature: 15 °C to 30 °C (non condensing)
Connection: Two 10 mm (0.375 in) hose barbs
CAUTION: Internal condensation can cause damage to the power supply

Enclosure type: 7 U high, 19 in rack mount with integral rack mount ears, 25 mm (1 in) air space required on each side for ventilation
Size: 48.3 cm W × 31.0 cm H × 57.2 cm D (19 in × 12.2 in × 22.5 in) with handles removed
Weight: 74 kg (163 lb)
Shipping size: 63.5 cm W × 55.9 cm H × 73.7 cm D (25 in × 22 in × 29 in)
Shipping weight: 80 kg (175 lb)
Ambient temperature: 15 °C to 35 °C at rated accuracy, 5 °C to 40 °C at reduced accuracy
Humidity: 80% to 31 °C decreasing linearly to 50% at 40 °C, (non condensing)
Warm-up: 30 min at output current setting
Approvals: CE mark–low voltage compliance to EN61010-3, EMC compliance to EN55022-1
Calibration schedule: 1 year