What are resolvers and what can you do with them?

A resolver is a transformer with one fixed input winding and two rotating output windings placed at 90 degrees to each other. It can measure angles and rotation speeds with high precision. Resolvers are used for example in robots, machines, weapons, ships and planes because they are not only very precise but also extremely robust and reliable.

What are resolvers? Simply put, a resolver is a transformer with one fixed input winding and two rotating output windings placed orthogonal (i.e. at 90 degrees) to each other. Like a transformer, a resolver only works with alternating voltages. If you add a third output winding and space them 120 degrees apart instead of 90 degrees, the resolver becomes sync. Thus, synchros and resolvers are closely related and are often referred to as synchro-resolvers.

Resolvers are super accurate

They are used for example in robots, tools, weapons, ships and planes because they are not only very precise but also extremely robust and reliable. They withstand wide temperature ranges and can withstand shock and vibration. Solvers excel in harsh environments.

If you put an AC voltage on the input winding of a resolver, a voltage develops on the output windings. However, since output windings can rotate, the magnitude of the output voltage depends on the angle between an output winding and the input winding. One amplitude follows a sine wave, the other a cosine wave. From these magnitudes, the angle between the rotating and stationary windings can be calculated. It is also possible to determine the speed of rotation and its direction.

Resolvers are repeaters

In this video, we take a closer look at resolvers and, using an old audio amplifier, set up two of them as a master-slave repeater.

Resources

About Cedric Lloyd

Check Also

Featured Recipe: Strawberry Lemonade Cupcakes

Lemon sponge cake Makes 24 cupcakes Ingredients 2 cups cake flour 1/2 teaspoon of salt …