Current supplies

Current supplies

Twinleaf offers low noise current supplies that are ideally suited for use with Twinleaf magnetic shields to excite their internal coils. Total field magnetometers can be operated in a shield by applying a bias field. Zero field SERF magnetometers require applying small correction fields on all three axes to zero out the field. The current supplies can be used for any application that requires a stable electrical current.

Model comparison

Modulation inputNoYesNo
USB PowerYesYesOption
Output ranges (mA)±10, ±50, ±250±10, ±50, ±250+1000
MS-1 Z range (nT)±1300, ±6500, ±32500±1300, ±6500, ±32500+130000
MS-2 Z range (nT)±1500, ±7500, ±37500±1500, ±7500, ±37500+150000

How do I add modulation to the current?

All Twinleaf current supplies have a grounded output. As a result, multiple currents can be summed together with a simple T junction connector.

If the required modulation is small, it is often suitable to connect a modulation voltage through an appropriate resistor into the T junction. The injected current can also be capacitatively coupled in order to avoid affecting the dc current level.

Note that some models have a modulation input.


Twinleaf current supplies prioritize stability and low noise over accuracy. The digitally programmable supplies cannot replace a reference-grade multimeter. Since atomic magnetometers are intrinsically accurate, magnetic field coils and the current supply driving it can be calibrated by an atomic magnetometer.