# ferrite magnet as toroid transformer

by ramonegumpert
Tags: ferrite, magnet, toroid, transformer
 P: 183 Dear Experts I have a 1.5 cm ring magnet, you know, the black color type of common low magnetic power magnet. I wrapped 5 turns of copper wire around it on one side and then wrapped 10 rounds of another copper wire around it . I connected 5v battery to the 2 ends of the primary coil which is the 5 turn winding. I then measured with volt meter the secondary coil. I did not see the output voltage at the secondary coil increase. This is my noobie attempt. Please comment what could be wrong. Can a ferrite magnet be used to step up voltage? I want to step up the voltage by around 2 volts. Many Thanks. regards Ramone
 Sci Advisor P: 4,010 Transformers only work on AC signals, so you would have to switch your battery current on and off through the primary winding to see anything on the secondary. However, a ferrite magnet would be a poor choice for a transformer core. Better options would be normal ferrite or soft iron laminations from a transformer.
 P: 4,664 Are you talking about a toroidal "refrigerator" permanent magnet made of "hard" ferrite? You will need up to 300,000 amp-turns per meter. See attached table from http://www.what-are-magnets.com/10STRONTIUMCERAMIC.HTM Attached Thumbnails
P: 183

## ferrite magnet as toroid transformer

Dear Experts
So , what is the recommended way to stepup a 5v dc battery pack to 8volts, occupying minimal space? Kindly please offer me an idea.

I have sen videos demonstrating how a joule thief can light up a 3v led using just 1.5v. I wonder can this toroid be modified/ used as-is to function as transformer ?

Yes, i am using a toroidal fridge magnet.
its ferrite but permanently magnetised, i think. Is the effect different than a non-magnetised ferrite?

Cheers
P: 4,664
 Quote by ramonegumpert Dear Experts So , what is the recommended way to stepup a 5v dc battery pack to 8volts, occupying minimal space? Kindly please offer me an idea.
Use a boost converter, which are transformerless:http://www.linear.com/products/step-...st)_regulators
Other mfgrs also make similar chips.
 I have sen videos demonstrating how a joule thief can light up a 3v led using just 1.5v. I wonder can this toroid be modified/ used as-is to function as transformer ? Yes, i am using a toroidal fridge magnet. its ferrite but permanently magnetised, i think. Is the effect different than a non-magnetised ferrite?
Magnets are not suitable for transformers.
 P: 183 Thanks so much Bob S. I will get a ferrite toroid and try again. Cheers :)
P: 4,664
 Quote by ramonegumpert Thanks so much Bob S. I will get a ferrite toroid and try again.
If you need to make a toroid transformer circuit, be sure to use a soft ferrite. I personally would search for a boost regulator circuit from Linear.com, using a DIP package. How many milliamps do you need? I have built ferrite transformer circuits before, and the boost regulators are easier.
 P: 183 Dear Bob Thanks for your reply. I am looking at output of as high as 500 milliamps, input voltage of any between 9v to 12 v and output of 5.5 to 6v. Is it possible to get free samples of 1 or 2 units for testing? Thanks. Regards Ramone
 Sci Advisor P: 4,010 You get free samples if someone thinks you might buy $500 worth of something. So, they ask who you work for and what your position is. So, unless you are likely to buy a lot of something, you shouldn't ask for free samples. Almost free, though, are these on Ebay: http://www.ebay.com.au/itm/DC-DC-Con...item3f154a0adc Synchronous rectification, Max efficiency up to 98%. Input: 4.75-24V. Output: 0.93V-18V ( Buck Mode, the input must be 2V higher than output ). Output Current: continuous 2.5A ( Peak 4A). Price about$3.50 US. Which country are you in?

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