is it possible for transformer to change ac/dc output?

[bohl1076]

inside transformer can said input 120vac, output 35vdc.
but when i took a reading my meter said 32vac
can this be a faulty transformer?

 

[augie47]

did you measure the actual input voltage ?

 

[bohl1076]

no not at the time, but what input could make the output turn to ac?

 

[hurk27]

An AC meter will read DC but will be inaccurate but a DC meter will not read AC and could be damaged, are you sure you are not just reading DC with a AC meter? if you are reading AC then some or all the components of the power supply have failed, mainly the rectifiers/diodes

Actually a transformer does not change AC to DC or visa-versa, a transformer won't work on DC at all, but a power supply will change AC to DC, depending upon the type and rating it does this by transforming the voltage down to the needed level then passing it through some rectifiers or diodes which changes it to DC after the transformer, a power supply can include voltage regulation and filters to refine the DC to a much cleaner form of DC, but it all depends upon the requirements of the load

 

[broadgage]

A true transformer can not produce a DC output.
It requires an AC input, and the output will allways be AC.
In common parlance however, the term "transformer" is widely used to mean what should correctly be termed a "transformer and rectifier power supply unit" This will contain a transfomer, a rectifier, and often other components.

If a unit marked as having DC output, gives a reading of AC volts, this is probably because the output is not smooth flat DC, but contains AC superimposed on the DC, known as ripple.

Alternatively the unit may be defective or wrongly labelled.

 

[Besoeker]

inside transformer can said input 120vac, output 35vdc.
but when i took a reading my meter said 32vac

It sounds like you were expecting 35Vdc but got 32Vac which you were not expecting.
Is that a reasonable interpretation of your post?

 

[fmtjfw]

The spark coil in a model-T and more modern cars was a "transformer" with an interrupted DC input. A transformer induces voltage in the secondary when the current in the primary changes.

The spark coils had very few primary turns and lots and lots of secondary turns. This took the 6 VDC in the primary to several KV in the secondary.