damn bruh how old are you? 😲

62

+VoltLog The designation of primary and secondary is usually arbitrary. So if you are using a say 110 V to 12 V transformer, you can either supply 110V to is 110V winding (primary) and get 12V out, or you can input 12V and get 110V. And in the latter case 12V would be your primary. So for a step down transformer you can also use it as a step up transformer and vise versa.

While it is true that a transformer can be used as either step-up or step-down, those laminated core transformers you have shown are designed to step down the mains voltage of 110V to 230V (depending on where you live) to the voltage required by the circuit and are meant to operate at 50 to 60Hz. The fact that they can be operated up to several thousand hertz is simply a matter of the cores capabilities and not it's ideal operating frequency. While it is important to choose a core type based on the operational frequency of your circuit, that does not imply that you must tune your circuit to that of the transformers ideal operating frequency.

+DextersLab2013 The designation of primary/secondary is arbitrary in this case as it depends on what you want to use this transformer for. In the multiple winding scenario, if the windings are tapped, you can infer the phase of the winding by measuring the voltage across different taps. If the windings are separate, you can identify the phase either by using a scope or connect one side of the winding with a "reference" winding and infer the phase with respect to the reference via the generated voltage.

Kerry Wong Thanks, will have to dig out some transformers and experiment!

+Henri “Ketturi” Keinonen Also using a sweep and synchronising the scope the to signature generator, you could see how the voltage changes with frequency.

And you can tell the direction of the windings from a scope :).

​@@netman69no you can't

@@Chevroletcelebrity yes you can, when 2 of them go the same direction the polarity will be the same when you got a probe on both, it'll be opposite polarity (or phase shifted 180 degrees in other words)

@@netman69 no

Thanks!

Look at flyback types.. but frequency of operation considerably higher.

why don't you have a function generator? they can be had for a little over $50 used...

@@Chevroletcelebrity Thanks, I ended buying one. Thanks again.

There isn't really an input or output as transformer is bidirectional and depending on your use. You can use this method to figure out the rough turn ratio between to two windings.

he is applying constant low current for testing !

@@MixPickle404 Thank you

Internal resistance of 50Ω is connected in series with the function generator.

@@mohitinch823 Thank you for your answer.

You are welcome!

I have a SMPS transformer E1614 controlled by iW1677-01 that transforms 310 Dc (after rectification ) to 5V DC. The iW1677 switching IC operating frequency ranges from 2.1KHz to 72Khz. How can i test this transformer separately just as you did in the above video and what frequency and Vpp do i need to select in the function generator? Btw , when i'd selected 2.1Khz frequecny and 1Vpp sinusoidal Vave , the output was almost 10mV.

Would it be safe if i apply 310V Dc at primary side and try to control it with a transistor using function generator ?

No. You are probably better off by inputting into the secondary (say 1Vpp) and measure the output from the primary. You should see around 60V on the primary (depending on whether the 5V figure is regulated the actual voltage may vary)

Here are the measurements: 6V transformer: primary: 1Vpp at 2Khz output 6mV at 25Khz , output 29mV (after 25Khz output starts decreasing) When i switched the supply to secondary side Seconday: 1Vpp at 2KHz output at primary 12mV (aprox) at 25KHz output at primary 60mV ====================================================== What does the above measurements imply :)

I have a pulse generator and wanted to see if it will create a pulse on a coil which will be a closed circuit if that’s possible