Transformer vibration

[aslamshaikh42]

i m using one motor driver circuit to drive four 70ma motors
the driver ic is l298p
on single channel i m conneting two motors
total current consumption of the circuit is 500mA
the transformer rating is 24v/2A.
THE PROBLEM IS THAT THE TRANSFORMER STARTS VIBRATING WHEN THE SUPPLY IS TURNED ON & IF I DON'T CONNET CIRCUIT THEN ALSO IT IS VIBRATING CAN ANY ONE SOLVE MY PROBLEM

THANKS IN ADVANCE.

 

[awt]

hi, these are the two possible cause:
1) it is possible that primary winding (no of turns) is not sufficient-check it out
2) there might be short-circuit somewhere in the windings
good luck

 

[MrAl]

i m using one motor driver circuit to drive four 70ma motors
the driver ic is l298p
on single channel i m conneting two motors
total current consumption of the circuit is 500mA
the transformer rating is 24v/2A.
THE PROBLEM IS THAT THE TRANSFORMER STARTS VIBRATING WHEN THE SUPPLY IS TURNED ON & IF I DON'T CONNET CIRCUIT THEN ALSO IT IS VIBRATING CAN ANY ONE SOLVE MY PROBLEM

THANKS IN ADVANCE.

Hi,

As awt mentioned there could be a problem with the transformer. Some transformers do vibrate and make noise too so sometimes rubber mounts are used. This usually happens in higher power circuits though, and sometimes sound deadening material is used inside the enclosure to help reduce the ambient noise which can be very very annoying to a human operator.

One of the causes is a DC offset in the transformer primary, but it could be in the secondary too due to the output circuit drawing an asymmetrical current. To find out if this might be the cause, you can try loading the transformer with just a regular power resistor and see if the noise goes away. You would need to load it to the same value as expected in normal operation.

 

[Diver300]

It could just be loose laminations in the transformer.

They are usually varnished to stop that happening, but mechanical clamping can also be used.

 

[aslamshaikh42]

Hi,

As awt mentioned there could be a problem with the transformer. Some transformers do vibrate and make noise too so sometimes rubber mounts are used. This usually happens in higher power circuits though, and sometimes sound deadening material is used inside the enclosure to help reduce the ambient noise which can be very very annoying to a human operator.

One of the causes is a DC offset in the transformer primary, but it could be in the secondary too due to the output circuit drawing an asymmetrical current. To find out if this might be the cause, you can try loading the transformer with just a regular power resistor and see if the noise goes away. You would need to load it to the same value as expected in normal operation.

thanks for reply

 

[Dragon Tamer]

Is it actually vibrating or is it just humming like all transformers do?

 

[DerStrom8]

Just about any AC transformer "hums," but I have noticed that if there is a short, or if the load on the secondary is to large, the transformer sometimes begins to vibrate. I recommend you check for shorts, and also make sure you have the proper transformer for you application.
Der Srom

 

[cachehiker]

It could just be loose laminations in the transformer.

I've seen that very thing on dozens of cheap knockoff transformers. It has been a little more common for us to have bobbins that don't fit the core well or to have an inner layer of windings that weren't wrapped tightly enough around the insulating material. Many are dipped in lacquer to keep them in place but we've managed vibrate some loose. They quit humming and start buzzing when that happens. It can be proven with a small enough accelerometer but going through those motions is usually a matter of sourcing and purchasing wasting our department's time and money because their chosen and therefore "golden" supplier couldn't possibly get something like that wrong.