Application challenge
- Power semiconductor tests often combine high voltage, low-leakage measurement and short high-current pulses.
- The switch must not distort the leading or trailing edge of the pulse, and it must survive high repetition counts.
- A single relay may not carry the full system pulse current, so the load-sharing network becomes part of the switching design.
Design approach
- For very high pulse current, use multiple relay paths in parallel with ballast or series resistors so current is shared predictably.
- Energize the relay and allow contacts to settle before applying the current pulse; the local reference notes a minimum wait time around the millisecond range for high-current pulses.
- Separate low-leakage measurement paths from pulse-current paths when one relay type cannot optimize both requirements.
- Use Kelvin routing, short high-current loops and pulse-rated resistors to reduce inductive overshoot.
Engineering caution: catalog ratings are component-level references. For high-voltage, medical, EV, PV or ATE systems, verify creepage, clearance, leakage, thermal rise, EMC and lifetime in the finished equipment.
Related MiRelay series
HVFR high-insulation relays fit high-voltage isolation and low-leakage channels; HGFR mercury-wetted relays are useful for low-resistance pulse paths where mercury-wetted technology is allowed by the application and regulations.
Series mentioned: HVFR high-insulation reed relays, HGFR mercury-wetted reed relays, HVR high-voltage reed relays