Newbie question about transformers

Hypatia's Protege

Joined Mar 1, 2015
3,201
An iron-lamination transformer will indeed act as a low pass filter -- however the 'DC' offset will cause both saturation and excessive primary heating...

Best regards
HP
 

paulktreg

Joined Jun 2, 2008
778
An iron-lamination transformer will indeed act as a low pass filter -- however the 'DC' offset will cause both saturation and excessive primary heating...

Best regards
HP
Probably one of the most unhelpful answers I've heard in a long while!

Does the transformer know whether the input is AC or DC if it's a sine wave or square wave?

Frequency dependent I suppose?
 

Hypatia's Protege

Joined Mar 1, 2015
3,201
I'm sorry you find my response unhelpful...

Does the transformer know whether the input is AC or DC
I shouldn't think non-sentient objects could be said to 'know' anything --- Your statement seems to be a non sequitur?:confused:

As regards wave shaping/frequency dependance:
In lieu of specifics I assumed and stipulated an iron (lamination) core (and, hence, markedly "frequency dependent") transformer...

Best regards
HP
 
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#12

Joined Nov 30, 2010
18,167
Frequency dependent I suppose?
Very frequency dependent. I have seen transformers specifically designed to pass square waves inside a 1% precision machine, but they were not iron core. An iron core transformer can be taught to pass a square wave by applying the right capacitance in the right places, and in the right frequency range, but it will not automatically make a sine wave, just a sloppy square wave.
 

Thread Starter

ranch vermin

Joined May 20, 2015
85
Thanks gentlemen, In an ac sine wave case, is signal completely distorted but are peaks preserved through... i dunno maybe ~100 transformers in series? The cause is I have a crazy idea about using transformers as switches on a home from scratch made chipboard computer of wires and nails! (used as solenoid transformers.)

Dirty old rusty piece of poop on a bit of cheap wood - cant wait.

I guess I have to go get my wires and nails to know for sure - I looked it up on youtube didnt find anything useful.
 
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crutschow

Joined Mar 14, 2008
24,039
Any square-wave is AC but if it has any DC offset (average value is not zero), that will tend to saturate the transformer. The DC offset can be nulled by AC coupling the square-wave through a series capacitor.
How well the transformer transmits the square-wave depends upon the frequency response of the transformer and the frequency of the square-wave, but it will not, in general, convert the square-wave to a sine-wave.
 

Thread Starter

ranch vermin

Joined May 20, 2015
85
Sorry guys, NOW I GET IT!

Just because current doesnt pass 0 doesnt mean it isnt alternating, ill remember that for next time instead of confusing the lot of you with my inane gibberish and poor reading of the help provided.
 

Kermit2

Joined Feb 5, 2010
4,163
What does that mean about me? I think I followed along with everyone involved without any confusion.\ whatsoever

(Kermit runs to ask his wife if he has missed any meds lately) :)
 
Just because current doesnt pass 0 doesnt mean it isnt alternating, ill remember that for next time instead of confusing the lot of you with my inane gibberish and poor reading of the help provided.
FWIW By way of avoidance of just such confusion the term 'Pulsating DC' is commonly applied to varying 'functions' having offsets preclusive of polarity inversion...

Best regards
HP :)
 
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