how can I indentify a transformer

[glmclell]

I have a mystery transformer, the only marking is ATEE1901A

its about 19mm x 12mm x 18mm, wrapped in yellow

it kinda looks like an audio transformer that I've seen in other gizmo's i've opened up.

the transformer is at the output stage of a DC to AC inverter for an el wire driver

 

[Nigel Goodwin]

I have a mystery transformer, the only marking is ATEE1901A

its about 19mm x 12mm x 18mm, wrapped in yellow

it kinda looks like an audio transformer that I've seen in other gizmo's i've opened up.

the transformer is at the output stage of a DC to AC inverter for an el wire driver

You already know exactly what it does, what else do you need to know?.

 

[glmclell]

I was wonder if there is a way to identify the turns ratio, etc..

I'm tryin to build another inverter based on the one I have ... the rest of the components are all just basic, caps, resistors, a trans and a diode... the transformer is the only unknown

but now that I think about it, just about any step-up transformer (or a step down wired backward?) should work, it'll just change the output voltage right?

 

[Nigel Goodwin]

I was wonder if there is a way to identify the turns ratio, etc..

Only by unwinding it and counting the turns.

I'm tryin to build another inverter based on the one I have ... the rest of the components are all just basic, caps, resistors, a trans and a diode... the transformer is the only unknown

but now that I think about it, just about any step-up transformer (or a step down wired backward?) should work, it'll just change the output voltage right?

It should work, at least to some extent, however the EL transformer will be designed for high frequency use (which is what makes it small).

 

[Crofty]

When I mess with reverse engineering mystery inductors/transformers I us an LCR bridge to glean info on the device. I measure the DC resistance of the winding/s then measure same on inductance setting. This gives enough useful info for duplicating the device.

Steve

 

[panic mode]

When I have to identify transformer, I simply use another transformer.
To identify coils first use conductivity check (ohmmeter), label the
ends than take any coil and connect it to low AC voltage source (3-6VAC)
which is normally supplied by other transformer. Use AC voltmeter
to get the voltages on any coil/tap you want then do the math...
Don't forget to check the power rating. For low frequency (50/60Hz)
transformers this can be done based on type/shape of core and size of
cross section. For switching PSU things could get a bit trickier but if you
are salvaging components from some old PSU, you should have good
idea of it's power.

 

[andhi_132]

why high frequency trafo have smaller size than normal trafo for same turn ratio and power ?

 

[Nigel Goodwin]

why high frequency trafo have smaller size than normal trafo for same turn ratio and power ?

One simple reason is the inductive reactance of the winding, a transformer with very few windings will have a low inductance - so if you stick it across 50Hz mains it will act like a short circuit, drawing excessive current and blowing things!. The same inductance at a much higher frequency, 100KHz is common, will have a much higher reactance and not draw excessive current.

Try working out the reactance values for various values of inductance at both 50Hz and 100KHz - you will soon see what I mean!.