PSTT PC / PSTT SC / PSTT ZC Active Trigger Units for Thyristors The Active Trigger is an economic replacement of pulse transformers including all associated circuitry in phase controlled thyristor equipment. Due to the small control current it becomes the ideal link between any size of thyristor and the control intelligence. Each Active Trigger can trigger two thyristors and is intended for mains voltages from 115V to 690Vrms. Its operation is based on an optically activated current source connected between anode and gate of the thyristor to be triggered. Thus a small electrically isolated control current initiates a large gate current without the necessity of a gate drive power supply. Three different application specific types are available. PSTT PC - controlled rectifiers, ac controllers, dc motor control, all other applications PSTT SC - economic low cost ac controllers PSTT ZC - zero crossing switching – heating, welding, power factor correction PSTT PC Top view in mm PSTT SC Top view in mm A2 K2 G2 G2 K2 PSTT ZC G1 K1 Height 19 mm PCB hole size 0.8 mm G1 K1 Height 23 mm PCB hole size 0.8 mm ABSOLUTE MAXIMUM RATINGS Type PSTT PC/12 PSTT PC/20 Parameter Symbol PSTT SC/12 PSTT SC/20 PSTT ZC/12 PSTT ZC/20 Vp 1200 2000 Peak voltage-positive and negative Nominal mains voltage Vm 400 690 Continuous DC voltage V= 400 690 Turn-on delay for gate current >1A tgd 5 5 Input-output isolation Vi 5300Vrms 60Hz 1min VDE0884 Input-output transient immunity (dv/dt)c 5000 Device transient immunity (dv/dt)d 2000 Ambient temperature range Ta -25 to +85 External gate cathode short circuit during operation can be destructive Unit V Vrms Vdc µs V/µs V/µs °C POWERSEM GmbH, Walpersdorfer Str. 53 2006 POWERSEM reserves the right to change limits, test conditions and dimensions 91126 D- Schwabach 1/3 Phone: 09122 - 9764-0 Fax.: 09122 - 9764-20 PSTT PC / PSTT SC / PSTT ZC TECHNICAL DATA at 25°C Type Parameter 200mA gate current threshold 1.2A gate current threshold Gate current rise time at anode Voltage of Symbol Vgtl Vgth 100V 200V 400V 800V 1200V Peak gate current (typical) Anode-cathode current at Vp Maximum off state gate current Minimum control current Recommended control current Control input voltage drop at 12mA Maximum reverse control input voltage Turn-on delay time at Ic=12mA Zero crossing threshold for PSTT ZC (di/dt)g Ip In Io Icm Ic Vin Vinr tdi Vzt PSTT PC/12 PSTT SC/12 PSTT ZC/12 10 24 2.5 3 4 6 1.3 4.4 2* 7 12 typ. 1.2<1.5 6 25 <20 PSTT PC/20 PSTT SC/20 PSTT ZC/20 16 36 1.2 2 2.5 3 4 1.3 5.1 2* 7 12 typ. 1.2<1.5 6 25 <20 Unit V V A/µs A/µs A/µs A/µs A/µs A mA µA mA mA V V µs V *PSTT ZC < 40µA HIGHLIGHTS Economic – very easy to use – small size – powerful gate pulse triggers large and small thyristors. Eliminates gate drive power supply – proven reliability in harsh industrial environment. APPLICATION INFORMATIONS As the gate current is derived from the anode of the thyristor, the control circuit only needs to supply the recommended control current which can be supplied directly from the output of many logic devices. It is advisable to maintain the control current over the entire conduction period of the thyristor. Once the thyristor is triggered, the gate current ceases to flow because the anode voltage drops below the threshold voltage. The control input consists of the light emitting diode of an optocoupler. Any such optical component is subject to aging at elevated temperatures. Although the minimum control current Icm is well below 7mA, a 12mA control signal is recommended to ensure reliable operation beyond 100’000 hours in a worst case design. The turn-on delay tdi can be reduced by pulse shaping, because it is inversely proportional to the control current. Because the device derives its power from the anode of the thyristor, a minimum operating voltage is required before any current can flow from the anode to the gate. This threshold voltage limits the minimum regulated output voltage. For example for a single-phase 115V ac controller triggered by a 1200V unit it is below 0.12%. For a 400V supply it is much less and can safely be neglected in most applications. POWERSEM GmbH, Walpersdorfer Str. 53 2006 POWERSEM reserves the right to change limits, test conditions and dimensions 91126 D- Schwabach 2/3 Phone: 09122 - 9764-0 Fax.: 09122 - 9764-20 PSTT PC / PSTT SC / PSTT ZC The thyristor is triggered from a current source with a maximum voltage of 22V. This allows for twisted gate leads of up to 1m while maintaining a high rate of rise of the gate current. Note that the envelope of the voltage across the thyristor to be triggered can have any desired shape provided the rms value is below Vm and the peak value does not exceed Vp. Both the PSTT SC and PSTT ZC have one control input only. This means that the thyristor with a positive anode voltage will be triggered when a control signal is present. The connection diagrams below show the typical application of the Active Trigger in mains operated systems using thyristors with current ratings from a few Amps up to several thousand Amps. CONNECTING DIAGRAMS PSTT PC PSTT SC PSTT ZC +Vs A2 Logic Output + K1 G1 - + +Vs G2 K2 + 12mA sink Logic Output G2 G1 K1 12mA sink - K2 - POWERSEM GmbH, Walpersdorfer Str. 53 2006 POWERSEM reserves the right to change limits, test conditions and dimensions 91126 D- Schwabach 3/3 Phone: 09122 - 9764-0 Fax.: 09122 - 9764-20