Functional description of active Trigger Unit for thyristor control by logic circuit output signals from microcontrollers, microprocessors, CPLDs or FPGAs

Functional description of the Trigger units

Weiter zur deutschen Funktionsbeschreibung des Trigger Moduls für eine direkte Thyristor-Ansteuerung durch Logikschaltkreise mit Mikrocontrollern, Mikroprozessoren, CPLDs oder FPGA

Functional description of active Trigger Unit for thyristor control by logic circuit output signals from microcontrollers, microprocessors, CPLDs or FPGAs

Technical features and performance of these Trigger Units for firing SCR / Thyristors

  • Trigger control for thyristors by logic circuit output signals from microcontrollers, microprocessors, CPLDs or FPGAs
  • Optical control for any type and size of thyristors, including amplifying-gate devices
  • A high electrical isolation is warranted due to opto-coupler input circuit or fibre-optic cable devices
  • The recommended control current for the trigger signal is 12mA
  • The standard units are intended for mains voltages of 100 – 690 Vrms
  • The high voltage units are intended for mains voltages of 1250 and 2500Vrms
  • The EZYTrigger units are working under all possible loads including large inductive loads
  • There is no extra power supply needed, because the gate-current derives from the thyristor anode
  • The integrated gate-current control circuit allows twisted gate leads up to 1m
  • The compact design allows saving space layout of the PCBs
  • The EZYTriggers have a high interference resistance under difficult operational conditions
  • The AT410 series replaces two pulse transformers with single secondary windings and the AT413, AT414 or the AT416 can replace a single transformer

Compact design for space saving layout of PCBs

Qualified compact SCR / Thyristor Trigger for applications like Inverter welding systems, Cathodic protection systems, Variable speed drives, Traction Power Supplies, GTO gate drive units w/ static compensation or UPS- uninterruptible power supply

Application example with Trigger Modules

Qualified SCR / Thyristor Trigger for applications like High power rectification, Softstarter, Battery charger equipments, Induction heating systems, DC Motor Drives, Conveyor system drives, Resistance welding switches or Cooling systems

Functional description of EZYTrigger Unit


  • Upon application of the control current, the thyristor receives a fast-rising gate current which is fully maintained until the anode voltage of the thyristor collapses below the threshold voltage after it is triggered
  • This method of operation accounts for the low power dissipation of the trigger unit
  • The thyristor will be reliable triggered with an 8 - 12mA signal and a small turn-on delay of approximately 25µs
  • Current flow is initiated by an opto-coupler which provides the electrical isolation
  • By maintaining the gate current long enough to reach the latching current the system can be safely used in applications with large inductive loads
Qualified compact SCR / Thyristor Trigger for applications like Emergency Lighting Control, Electron Beam welding, Lighting Control, Wind Turbines, Standby Power Systems, Electric Vehicles or Electrocoating

  • The anode voltage of the thyristor must be at least 14V before the gate current reaches 200mA
  • The full gate current is maintained until the thyristor triggers, it is terminated when the anode voltage goes below 14V
  • The rise-time of the gate current is approximately proportional to the supply voltage and is typically 2A/µs
  • The full forward voltage dv/dt can only be re-applied 100µs after removing the trigger signal from the control terminals
  • The envelope of the voltage across the thyristor can have any desired shape provided the rms value is below the nominal voltage Vm and the peak value does not exceed peak voltage Vp

For general survey please download the EZYTrigger Main Catalogue with all types of modules



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Mail contact for active Trigger Unit for thyristor control by logic circuit output signals from microcontrollers, microprocessors, CPLDs or FPGAs

Are you interested in testing these trigger modules on your electronic application?

Please contact and quote us the number of desired type of modules and we will send you an introductory price for this test package. We would be pleased to receive your message and to advise you in all matters concerning the desired product.


Andreas Müller Electronic GmbH

Telefon: 0 24 32 - 4 96 77

  Fax: 0 24 32 - 4 96 56

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