Home > categories > Electrical Equipment & Supplies > Transformers > Ok I tried to make my own step up transformer that uses a pulsed DC current in the primary and it doesn't work?
Question:

Ok I tried to make my own step up transformer that uses a pulsed DC current in the primary and it doesn't work?

!!! I took a cardboard cylinder from a used firework, dug out all the crap, wrapped 160 turns of tinned copper wire on the outside tight and evenly so it is a beautiful solenoid, held it in place with 2 rubber bands. That was the secondary. Then I wrapped an insulated steel wire around a screwdriver shaft 10 times, stretched it out a little inserted a chopstick into this primary and inserted the chopstick into the firework. I then held it all in place with tissue paper and tape and wired the primary up to a pulsed DC circuit which was made of 3.0 volts wired to a steel file which I rubbed the electrode across. The secondary was wired to a current detector but I got no signal! Why is there zero inductance in my transformer and why is there no current at all? It can't even light up a small lightbulb!!

Answer:

Capital and minuscule letters are differentiated in the Roman, Greek, Cyrillic, Armenian and Coptic alphabets. Most writing systems (such as those used in Georgian, Glagolitic, Arabic, Hebrew, and Devanagari) make no distinction between capital and lowercase letters, a system called unicase. Indeed, even European languages did not make this distinction before about 1300; both majuscule and minuscule letters existed, but a given text would use either one or the other. In alphabets with a case distinction, capitals are used for capitalization, acronyms, and emphasis (in some languages).Capitalization is the writing of a word with its first letter in uppercase and the remaining letters in lowercase. Capitalization rules vary by language and are often quite complex, but in most modern languages that have capitalization, the first word of every sentence is capitalized, as are all proper nouns. Some languages, such as German, capitalize the first letter of all nouns; this was previously common in English as well. (See the article on capitalization for a detailed list of norms).
There is a little more to transformer design than this. Your secondary should have used insulated wire (varnished or enamel would do) as even one turn shorting will give problems. Also, you need to consider the magnetic circuit formed by the steel core. It is usual to use soft iron for this as otherwise the hysteresis will be too large. The entire magnetic flux needs to be concentrated into the secondary so you will need to consider the magnetic path. The transformer is essentially just two (or more) inductors, sharing a common magnetic path. Any two inductors placed reasonably close to each other will work as a transformer, and the more closely they are coupled magnetically, the more efficient they become.
I think your current detector was not good enough. Was it a bulb? It wouldn't supply enough current for one. I'd suggest you need a more sensitive indicator. What you should see is about 48V. AC on the secondary, plus some more due to the inductance of the primary. Your electrode you rub on the file must be very small, such as the end of a wire, to give an interruption. You could probably get an indication on a digital multimeter on an AC range. Just don't expect it to be an accurate reading. If you're game, you could hold one end of your secondary in your fingers, and touch the other end to your tongue, then do the file thing. But you might only want to try once! I often use my tongue for low voltage indications. But 48V. would be a bit much for me. Ouch!

Share to: