# My Small Transformer

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## Introduction: My Small Transformer

this is my homemade transformer..i mean small...
its a transformer from a rc car charger...
i winding the primary coil(input)5 turn and in secondary coil(output)20 turn...
it is a e_block transformer...
i use ac adapter 12v as the input voltage...
i use 18v small pc fann...
its doesnt workk!!!!1
but why???
i hope u guys can help me solve thiss...
thanx you.....
one more...i want to make step up transformer.....
help me....

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## 29 Discussions

I do not think so that a DC powered RPS would work . Becoz
chajgng current would produce magnetic flux which induces
voltage

i think i should start something like this instead of just blindly:P trying to make myself a 45-0-45 VAC which i failed twice miserably(:

when you plug in the DC adaptor to the wall, it has a transformer in it that is converting the wobbly goodness of polyphase AC wall current into the smooth non serrated butterknife uselessness of DC. When your butterknife current tries to saw through that meat transformer, nothing happens. You need wobbly goodness by either using AC directly, or by recreating AC from your DC. Engineering types will tell you all sorts of stuff, but basically, you need to turn your flat line (on the oscilloscope) into a series of serrated teeth. First they will get boxy with part 1 of the circuit, then the boxy shapes will get curved with part 2. I think it's kind of like acceleration vs. velocity. When you are traveling in an airplane, you don't notice how fast you are going until you change direction. Transformers are the same way - unless the voltage is constantly changing, it adapts and then ignores whatever voltage it is set to.

Here's another analogy: DC is like gravity, reliable, and always there, but to get a transformer to work, you need to make fake gravity, (fake AC), which is kind of like putting water in a bucket and spinning it around. The water doesn't fall out when the bucket is upside down because the water experiences fake gravity from the bucket. Scientists have fancy words to describe centripetal fake gravity, but even a 3 year old can keep the water from falling out, but it takes that extra step of spinning the water up and down in a circle. Pulse Width Modulation can probably do that. I dunno. I've only been studying electricity since March.

Try http://lushprojects.com/circuitjs/ to simulate and develop a functional circuit. It should help.

The Fan is DC and the input is AC. The transformer is going to output what the input is so an input of AC will yield AC output. DC input will yield DC output. You need some sort of converter to get dc into the transformer.

A transformer will not operate on DC voltage, unless it is modified, pulsed, etc., however, the transformer is made to transform a clean sinewave, not a square wave, even though the square wave will make the transformer function, it will not function in the correct manner since the wave is not linear. The ac wall wort transformer must have an AC output, not DC... this is the first problem. Second, when you get the transformer to work, you will have to put a bridge rectifier on the output with a smoothing capacitor so the output voltage is a DC current, and, the voltage output spikes are absorbed to keep them around 18 volts and, the additional voltage spikes will be stored into the cap so it is released smoothly and at a lower voltage range spread out evenly to give the fan a smooth and steady DC voltage so the fan operates at the correct voltage without getting smoked from the higher voltage emf pulses.

Sorry the input has to be AC. Change the voltage to DC after the transformer with a converter.

Your set up is step down transformer so the ratio of voltages of the primary and secondary coils is equal to the inverse of the no of turns of primary and secondary so the voltage generated is 3volts so the 18 volt fan doesn't works and also the current is DC but not Ac

i think the flux produced in primary is not completely linked with the secondary coil... try increasing the no. of windings in both primary and secodary... then give its output to a regulator and then to the fan...

to induce current in secondary coil the primary coil should have A.C. input D.C will work only at the moment when u initially connect the +ve and -ve leads to the primary , it will not work after that (as in DC the current only fluctuates in the beginning when when u touch it to the leads of the primary .).

So a transformer requires AC input and WILL gives out AC output .

if u want to convert the AC output to DC use a bridge rectifier(search bridge rectifier on google ).

I know this is old, but if you use a transistor-transformer setup, you can rapidly turn the dc from nil to max repeatedly, creating a magnetic flux in the process. The voltage does not have to be traditional ac, it just has to vary. You certainly can do this with dc using a transistor, and if the frequency is high enough the fan will spin without you being able to notice that it isn't continuous. This is how joule thiefs work.

all the below cmnts are wrong the reason is the output after step up will be AC and not DC.Theoretically only AC current can be stepped up.the a DC fan will not run on AC supply

I am shocked are you crazy ? this small winding ! this shortcircuit the AC
adapter you are using . you need more lots of winging at primary atleast 10
ohm resistance okey baby

Why???