The PA20100 is an ultra stable magnet power supply unit. It is used to feed quadrupole magnets of the PTB Metrology Light Source storage ring in Berlin.

Based on a hybrid, air-cooled power stage, the power supply provides output currents of 100 A at output voltages of up to 20 V.

The overall stability of the output current is better than ±10 ppm. This includes peak to peak ripple and noise, repeatability, thermal drift and drift over 24 hours.

The hybrid power stage consists of a switched-mode preregulator followed by linear output stage. This configuration ensures high efficiency and lowest ripple and noise.

Current setpoint, actual values, control and status signals are exchanged via a control interface. A slot is allocated to accomodate the customer's proprietary control interface or a standard interface card. This allows for a smooth integration of the unit into the control system of the facility. Precision monitoring outputs indicate the actual values on additional connetors on the front panel.

In case of sudden setpoint changes, the rate of change is restricted by means of an adjustable precision slew-rate limiter.

Two DCCTs are used to measure the output current for regulation and for monitoring independently. This allows the control system to detect even small deviations in the output current.

The unit is fully protected against overload, overtemperature and short circuit. Many operational parameters like internal supply voltages, internal temperatures, magnet ground leakage, load current oscillation, DCCT operation and external interlock inputs are monitored. In case of a malfunction the unit will shut down and the status is stored. For a quick overview the complete status information is indicated on the frot panel. A deep insight, including operational status and event log, is gained via a service interface.

The construction is based on a 19" housing, 3 units high.


Output Current 1 – 100 A
Output Voltage 0 - 20 V
Overall Stability < ±10 ppm (over ambient temperature range; including ripple, noise, repeatability and drift over 24 h)
Ripple + Noise < 5 ppmPP (load: 40 mH / 150 mR)
Absolute Accuracy < ±100 ppm
Slew-Rate 3 – 100 A/s (adjustable)
Common Mode Voltage -100 - +100 V
Mains Voltage 230 VAC / ±10% / 47 - 63 Hz
Power Factor > 0.98
Ambient Temperature 0 - +40°C (operating); +20 - +30°C (maintaining drift specifications)
Dimensions (w x h x d) 483 x 132.5 x 554.5 mm (19", 3 U)
Weight 40 kg