It is important that they are galvanically isolated by opto-isolators – electronics due to the fact that they must be powered by an external high power supply.
Ito ay mahalaga na galvanically sila ay ihiwalay ng opto isolators – electronics dahil sa katotohanan na dapat sila ay pinalakas sa pamamagitan ng isang panlabas na mataas na supply ng kapangyarihan .