1021 DC Current Source with Null Indicator

1021 DC Current Source with Null Indicator
  • 100mA output with overload protection
  • 0.02% accuracy
  • Wide range of applications
  • Safety terminals
  • Battery level indicator
  • Portable with protective boot



The 1021 is a precision DC Current Source suitable for calibration and test applications from micro-amp levels up to 100mA.

The 100mA output with overload protection is based on the popular Time Electronics type 1007 millivolt source and incorporates many of the well-proven features. The instrument is overload protected and a front panel indicator shows when insufficient drive voltage is available. Maximum output voltage is adjustable between 14 volts and 40 volts, with a maximum output power of 2.4 watts.

The unique circuit design ensures that it stays well within specification for at least 12 months. Variation with temperature is better than 60 ppm per ºC, and typically better than 20 ppm per hour at constant temperature. To improve the switch reliability, additional back-up contacts have been used – even if a contact fails, the 1021 will still operate correctly.

The accuracy and stability are such that a wide range of applications are possible. In the process industries it may be used to test and calibrate current sensitive transducers, and their associated indicating and recording instruments. The semiconductor industry requires constant current sources for parameter measurements. It may also be used to measure DC current accurately by using the null facility to back off the unknown current. Resolution of 1µA is possible.

Safety Terminals: Fully compatible with 4mm shrouded plugs, as well as standard plugs, bare wires, and spade terminals.

Added Protection: The 1021 comes fitted with an ergonomic rubber boot (9028) providing increased protection and durability. The boot has a textured grip for comfortable handling and openings at the top and bottom to allow access to the battery meter and a position to place labels if required. The boot is easy to remove if the user prefers a stand-alone unit or to house the 1021 in the 9027 carry case.


Transducers: The ability to source and measure current makes the 1021 ideal for testing and calibration of many types of current transducer and their associated measuring equipment.
Semiconductor Parameters: The 1021 covers many applications in a wide variety of semiconductor measurements including; forward voltage drops, zener diode characteristics and temperature coefficients, transistor gains (hfe) and saturation voltages. Characteristic curves of devices can be easily plotted by selecting suitable output currents on the 1021. It can also be used to drive Hall effect devices.
Resistance and Temperature Measurement: Low ohm and contact resistance of relays, switches, connectors, etc can be easily measured using the 1021 as the current source in a 4-terminal kelvin system where lead and probe resistance do not affect the accuracy of the reading. This method can also be used in thermometry for calibration and measurement of platinum-resistance thermometers and thermistors.

Related Products: 1024 DC Current Calibrator, 1030 Voltage and Current Source, 1044 DC Voltage and Current Calibrator, 1007 DC Millivolt Potentiometer and Calibrator