DC Current Sources

DC Current Sources

​The Model 100 through 120 current sources have been replaced by the Model 121 DC current source.

Model 100 & Model 101 features

  • Battery powered
  • 10 µA factory-preset output current
  • Internally programmable from 1 µA to 1 mA
  • No AC noise
  • Choice of compliance voltages:
    • Model 100: 2.5 V
    • Model 101: 5 V

Model 102 features

  • 10 µA factory-preset output current
  • Internally programmable from 1 µA to 1 mA using a fixed program resistor
  • Compliance voltage of 8 V

Model 110CS features

  • 10 µA factory-preset output current
  • Externally programmable from 1 µA to 10 mA
  • Compliance voltage of 11 V

Model 120CS features

  • Switch-selectable output current from 1 µA to 100 mA
  • Current reversal switch
  • External programming capability
  • Compliance voltage of 11 V (to 50 mA)
Model 100 and Model 101

The Models 100 and 101 are battery-powered DC current sources which provide a very stable output current without the noise commonly associated with AC line-powered instruments. They are well-suited for field maintenance and periodic monitoring of sensors, as well as operation in a highly noise-sensitive environment.

The main difference between the 100 and 101 is their compliance voltage: the Model 100, with a 2.5 V compliance voltage, is well suited for silicon diode applications including Lake Shore DT-470 and 670 diodes. The Model 101 has a compliance voltage of 5 V which is required for use with Lake Shore TG-120 GaAlAs diodes, or if the user desires to connect two silicon diode sensors in series. While the output current of both units is factory preset at 10 µA, the user may reprogram the unit to any value between 1 µA and 1 mA by changing the internal programming resistor.

Model 102, Model 110CS and Model 120CS

The Models 102, 110CS, and 120CS are precision DC current sources suitable for benchtop use. They are capable of higher output currents and compliance voltages than their battery-powered counterparts.

The Model 102 provides excellent performance at low cost. The output current is factory preset at 10 µA, but the unit may be reprogrammed to any value between 1 µA and 1 mA by changing a programming resistor inside the instrument. Compliance voltage is 8 V. Power is supplied to the unit by an external AC wall-mount supply. The supply type must match the AC line voltage available and must be specified when ordering.

The Model 110CS offers a higher compliance of 11 V. The output current can be externally changed to any value between 1 µA and 10 mA by connecting a programming resistor to the terminal block on the unit’s rear panel. AC line voltage is jumper-selected inside the unit. Desired line voltage should be specified when ordering, but the setting can be changed at any time by the user.

On the Model 120CS, output current is selected with a rotary switch on the front panel. Eleven fixed values span the range of 1 µA to 100 mA and a compliance voltage of 11 V. The 1× and 3× switched increments correspond to approximate decade changes in power with a resistive load. For odd current values, a programming resistor may be connected to the terminal block on the unit’s rear panel. This source is ideally suited for use with resistance sensors where resistance may vary with temperature by as much as 6 orders of magnitude. The current reversal switch allows compensation for thermal EMF, important when measuring resistors at low voltage. AC line voltage is jumper-selected inside the unit. Desired line voltage should be specified when ordering, but the setting can be changed at any time by the user.