Excelitas offers two different types of circuits and transformers used to introduce the voltage necessary to achieve ionization

 – series injection triggering and external triggering with the associated coils. 

External triggering uses a high voltage trigger pulse to create a thin ionized streamer between the anode and cathode within the lamp. 

The coupling of this voltage to the lamp can be achieved using a thin nickel wire wrapped around, or a metal stripe on the surface 

of the lamp envelope. These types of trigger coils are generally lighter, smaller, and less expensive than those used for series injection triggering. 

Series triggering offers higher timing accuracy and is often used in combination with liquid cooled lamps in lasers. 

Trigger coils are typically larger, since they not only generate the HV ignition, but also must cope with lamp currents 

in the order of several thousand Amps.