In applications that call for a thyristor but where it would be advantageous to have gate control for turning off a thyristor instead of the gate being limited to only turning on the thyristor, then you need to consider the gate turn-off thyristor. These gate turn-off thyristors are great for variable speed motor drives and also for high-power inverters that power traction motors in electric locomotives and hybrid electric vehicles.

GTO thyristors are the component of choice when it comes to very high power converters. For applications requiring very low dynamic and on-state losses, look for gate turn-off thyristors that feature buffer layer and transparent emitter technologies. For applications requiring fast switching, make sure the GTO thyristors feature fine pattern technology. To contact a gate turn-off thyristor manufacturer or a suppliers of gate turn-off thyristors, see the following:

1. Get gate turn-off thyristors to use in variable-speed tools.

2. Select GTO thyristors for use in current sourced inverters.

3. Choose gate turn-off thyristors to be used in voltage sourced inverters.

Action Steps
The best contacts and resources to help you get it done

Select gate turn-off thyristors suitable for variable-speed motorized devices

If you are developing variable speed motorized tools, you need to have control over the voltage and frequency of the power applied to the motor. A simple-to-design technique and one that can be used with multiple motors is a voltage source inverter (VSI) circuit, which typically employs gate turn-off thyristors to control the frequency applied to the motor. The following gate turn-off thyristor suppliers carry GTO thyristers well suited for this application.

I recommend: Darrah Electric carries gate turn-off thyristors including the full range of ratings and sizes all the way to 6.5 kV and 4 kA. Dynex manufactures gate turn-off thyristors ranging from 1300 V to 6500 V, including both asymmetric and reverse-blocking styles. They also provide a handy GTO cross-reference online if you have part numbers from a different maker. You can also contact gate turn-off thyristor supplier Larkin Power Components for a quote based on the specs.

Identify gate turn-off thyristors for use in current sourced inverters

If you're developing current sourced inverters, then you need to select GTO thyristors that provide reverse blocking. Visit each gate turn-off thyristor distributor below.

I recommend: Gate turn-off thyristor manufacturer Westcode Semiconductors incorporates special features into their GTO thyristors such as a buffer layer, fine pattern and transparent emitter technologies. Another supplier of gate turn-off thyristors is NTE Electronics, selling GTO thyristors for use in televisions.

Pick gate turn-off thyristors to be used in voltage sourced inverters

If you're developing voltage sourced inverters, then the reverse blocking feature is not necessary in your selection of GTO thyristors. See the gate turn-off thyristor distributors below.

I recommend: ABB is a GTO thyristor manufacturer that includes a buffer layer and transparent emitter in their GTO thyristors for very low-loss on-state and dynamic losses. They also have fine pattern for fast switching. Another of the more prominent gate turn-off thyristor manufacturers is American Microsemiconductor.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  When turning off, the forward voltage across the GTO thyristor must be limited to, say, 20% of the rated forward blocking voltage until the current tails off. If the voltage increases too quickly at turn off, not all of the device will turn off and the GTO will fail and could possibly even explode.