Heinzinger PTN 125-40 magnet power supply







Semiconductor Laboratory

Heinzinger PTN 125-40 magnet power supply

The Heinzinger PTN 125-40 is a DC power supply that can provide voltages of up to 125 V and currents of up to 40 A. In the magnet laboratory it is used to provide the current for the Bruker Magnet B-E 15 electromagnet. The magnet can be driven with a maximum continuous current of 30 A. It has two coils with a total resistance of 3 Ohm (1.5 Ohm each) so the voltage needed for maximal magnetic field is at 90 V. Changing the current through the magnet suddenly can lead to significant inductive voltage spikes. Diodes in the magnet are designed to prevent the voltage spikes but it is strongly advised to ever only slowly increase or decrease the current through the magnet with a rate of maximal 1 A/s.

Safety

The upper end of the voltage range of the Heinzinger PTN 125-40 is at 125 V which is just high enough to surpass the extra-low voltage range (< 120 V DC, < 50 Vrms AC), which carries a low risk of dangerous electrical shock, into the Low voltage range with a risk of electric shock.

Communication with the Heinzinger PTN 125-40 using Python

The Heinzinger PTN 125-40 is connected to the computer via LAN cable. Below is a sample script that makes measurements of the magnetic field with a FH 54 Magnetometer while sweeping the magnetic field.

# import the libraries needed to communicate with the Heinzinger power supply and the magnetometer from Heinzinger import DigitalInterface import MagnetPhysik # connect to the magnet power supply ptn = DigitalInterface() ptn.connect("TCPIP0::129.27.158.19::7::SOCKET") # connect to the magnetometer magnetometer = FH54() magnetometer.connect('COM4') magnetometer.set_unit_Tesla() magnetometer.set_range(FH54.RANGE_3T) # The supply should always be left with a current of 0 A. # Ramp the current to 0 A just in case it was left in another state. # The current should not be changed faster than 1 A/s to avoid voltage spikes in the magnet. ptn.ramp_current(0, slope=1) # The magnet has a resistance of about 3 Ohms. Set the voltage limit to more than 3 times the maximum current # that will be used. To keep the current from changing faster than 1 A/s, don't sweep the voltage faster than 3 V/s ptn.ramp_voltage(100, slope=3) # This is the main loop of the script that sweeps the magnetic field for current in range(0,30): ptn.ramp_current(current, slope=1) # Wait to let the field stabilize sleep(1) #Read out the magnetic field measurement_Tesla = magnetometer.read() print("I = " + str(current) + "A, B = " + str(measurement_Tesla) + " " + str(mm.get_unit())) # ramp down the magnetic field print("Shutting down to 0 A (Speed: 1 A/s)") ptn.ramp_current(0, slope=1) ptn.ramp_voltage(0, slope=3) # disconnect the power supply ptn.disconnect() magnetometer.disconnect() print("Finished")
B_field_sweep.py

Refer to the Python library Heinzinger.py for more details on communicating with the power supply.