40 kA PWM Coil Driver – Sky Blue Microsystems GmbH

EHT Modulated Coil Driver with 40 kA Pulse Width at 10 ms

EHT has developed a solution for driving a 40 kA current yet maintaining a flat top for 10 ms in an electromagnetic coil. In order to minimize the ripple on the coil, the circuit pulse width modulates at 100 kHz.

Each integrated power module (IPM) was tested at 2.5 kA/IPM. High current operation is demonstrated at 100 kHz. The voltage across the switch decreases over the course of the shot due to energy being drained from the capacitor bank. Current measured with a Rogowski coil and EHT Integrator. The current graph changes shape when the pulse width is changed during the shot.

EHT 40 kA PWM Coil Driver IPM testing waveform showing high current 2.5 kA operation, voltage across the switch, current in the coil, and saturated current transformer.
IPM testing Waveform of the EHT 40 kA PWM Coil Driver showing high current 2.5 kA operation, blue – voltage across the switch, pink – current in the coil, green – saturated current transformer.
EHT 40 kA PWM (Pulse Width Modulated) Coil Driver with modulated 100 kHz circuit pulse width to minimize ripple on the coil.
EHT 40 kA Pulse Width Modulated Coil Driver: circuit pulse width modulates at 100 kHz.