High Voltage Switches

Due to advances in semiconductor technologies, solid-state high voltage switches can now substitute thyratrons, ignitrons, spark gaps and electromechanical high voltage relays. Four main technologies (SiC, MOSFET, SCR and IGBT) are available covering 1 kV – 140 kV and 15 A – 16 kA:

TTL control input and low power electronics replace expensive heater supplies and drivers found in vacuum tube based solutions. PPM supply a range of 300 standard devices manufactured by Behlke as well as custom designs.

Find the component you are looking for in the table below or call us on +44 (0)1793 784389 and talk to one of our technical sales team.

Extreme rise and fall times

The Behlke solid-state switches have extreme rise and fall times. If your application does not require the full switching speed we suggest you the use the speed limiting option S-TT (rise & fall times slower by approx. 50%) in combination with the input low pass filter option LP. The speed limiting options help to minimise the high frequency difficulties typical for fast high voltage pulse circuits e.g. self-oscillating, self re-triggering, ringing and simplify the EMC design in general.

Using a free-wheeling diode network to prevent reverse currents

Fast solid-state switches are sensitive to reverse currents from unclamped inductive loads. Reverse currents may turn on the slow intrinsic (parasitic) FET diodes in an undefined way and can lead to a catastrophic switch failure. In particular turn-off operation, in combination with high turn-off currents, a fast free-wheeling diode network (fast serial blocking diode + parallel fast free-wheeling diode) should be implemented. This can be integrated with the switching module as option I-FWDN. Please discuss with PPM Power technical support form more information.

For more information about high voltage switches please see choosing a high voltage switch.

Fixed On-Time Switches

	On-Time Description	Maximum Voltage	Maximum Current	Switch On-time
Fixed thyristor/SCR switches	Current Depending	4 - 150 kV	1 - 16 kA	> 35 us
General Purpose Fixed MOSFET Switches	Fixed	4 - 150 kV	15 - 200 A	100 - 300 ns
Low Impedance MOSFET Switches	Fixed	0.5 - 40 kV	70 - 1600 A	150 ns
Ultra-Fast MOSFET Switches	Fixed	3 - 12 kV	60 - 200 A	120 - 200 ns
Low On-Resistance Fixed MOSFET Switches	Fixed	3 - 24 kV	60 - 1040 A	150 - 250 ns

Variable On-Time Switches

	On-Time Description	Maximum Voltage	Maximum Current	Switch On-time
General Purpose Variable MOSFET Switches	Variable	0.5 - 36 kV	12 - 640 A	> 50 ns
High di/dt MOSFET Switches	Variable	3 - 36 kV	200 - 3200 A	> 300 ns
Low Capacitance MOSFET Switches	Variable	3 - 140 kV	30 - 800 A	> 60 ns
Low On-Resistance Variable MOSFET Switches	Variable	0.5 - 21.6 kV	125 - 3750 A	> 150 ns
AC MOSFET Switches	Variable	1.2 - 36 kV	12 - 130 A	> 50 ns
General Purpose IGBT Switches	Variable	3 - 36 kV	800 - 9600 A	> 0.2 us
Variable Thyristor/MCT Switches	Variable	4 - 18 kV	3 kA	> 1 us
Push-Pull MOSFET Switches	Variable	2x 1.2 - 140 kV	2x 12 - 200 A	> 50 ns
Pulser Switches	Variable	(2x) 3 - 12 kV	(2x) 15 - 80 A	> 50 ns