Ac motor driving methods

[libyantiger]

Hello everyone

What kind of ac motors that can be driven with triac circuit and what kind of ac motors that cant be driven with triacs



For the ones that can be driven
Can we control the speed while the motor is loaded defining certain rpm...or just this method for unloaded ac motors like fans wherr we will expect certain rpm based on how much average voltage triac puts on fan

 

[BradtheRad]

I built a simple triac control to change speed of our wood stove fan. It drew little current from mains, being small. I believe it was the type known as a squirrel-cage motor. Evidently its speed is unrelated to AC frequency. It went fast or slow as I dialed the potentiometer.

The same for my window fan. I slow its speed by means of a step-down transformer.

And my opposite experience...

I tried to vary the speed of my reel-to-reel tape recorder by hooking up the triac controller directly to its motor. Evidently its speed is linked to AC frequency because it maintained the same speed as I reduced waveform On-time. Suddenly it stopped when power was insufficient. Then I increased waveform On-time and it started spinning at its designed speed.

 

[libyantiger]

I built a simple triac control to change speed of our wood stove fan. It drew little current from mains, being small. I believe it was the type known as a squirrel-cage motor. Evidently its speed is unrelated to AC frequency. It went fast or slow as I dialed the potentiometer.

The same for my window fan. I slow its speed by means of a step-down transformer.

And my opposite experience...

I tried to vary the speed of my reel-to-reel tape recorder by hooking up the triac controller directly to its motor. Evidently its speed is linked to AC frequency because it maintained the same speed as I reduced waveform On-time. Suddenly it stopped when power was insufficient. Then I increased waveform On-time and it started spinning at its designed speed.

So its experiential process ..is there any category for the types of motor that can and the ones that can not work on triac
Link or book that shows

Can some motors that are voltage dependant and can use triac work for toy electric car for children ...

 

[D.A.(Tony)Stewart]

Traics have problems with some magnetics like transformers and motors but not all.

Triac Universal Motor Speed Control Circuit Design Basics - Technical Articles

Triac circuits are well-known and commonly used for universal motor speed control. This article presents a basic design for a universal motor speed control circuit.

eepower.com

 

[FvM]

Can some motors that are voltage dependant and can use triac work for toy electric car for children

No. Toy cars use battery and DC motor. Triac control works for AC only. As the thread title already suggests.

Presume you are asking about AC induction motors, e.g. said fan motors. There are are also AC operated DC machines, e.g. in hair dryers, food processors or tools.

AC motors can be well triac control if they are loaded with a speed proportional or even over-proportional ( as it's the case with fans) torque and the slip characteristic is soft. The load torque produces a stable operation point on the slip versus torque curve.