Help cant get homemade toroid to work

Discussion in 'General Electronics Chat' started by nissan20det, Apr 22, 2015.

  1. nissan20det

    Thread Starter New Member

    Apr 3, 2015
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    Hey guys so Im not sure why this wont work.. what am I missing? Ferrite core, 30 gauge about 100turns with 10 turns of 24 gauge. Powering with 120v A/C (U.S.A.) transformed to 19.8v A/C 60Hz... I have nothing hooked up after this I am just trying to test output with DMM?I get no freq. Or voltage. Either way I hook this up... step up or down.??? 20150422_211843.jpg
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Unsuitable material for 60Hz?
    Max.
     
  3. dl324

    Distinguished Member

    Mar 30, 2015
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    Is the 24 gauge wire insulated?
     
  4. ScottWang

    Moderator

    Aug 23, 2012
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  5. t_n_k

    AAC Fanatic!

    Mar 6, 2009
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    If the TS is seriously comptemplating energising either winding direct from 120V mains supply I'm puzzled as to why this thread hasn't been locked.
     
  6. ScottWang

    Moderator

    Aug 23, 2012
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    He is not connected directly to the Mains -- Powering with 120v A/C (U.S.A.) transformed to 19.8v A/C 60Hz.
     
  7. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    At considerable risk of sounding a Pollyanna, I assume you are contemplating application of 19.8V (as opposed to 120v) to the 100 turn winding on the toroidal form...

    Anyway, the short answer is that the magnetic properties of ferrite (or iron powder) material is not suited to magnetic components operating at SLF/ELF...

    Best regards
    HP
     
    Last edited: Apr 23, 2015
  8. crutschow

    Expert

    Mar 14, 2008
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    The core may be saturating, but you should see something. :confused:
     
  9. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    The (toroidal transformer's) primary reactance may be so low at 60hz that he is effectively 'shorting out' his power supply xfmr...

    Best regards
    HP
     
  10. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Where's the power to the primary?
    upload_2015-4-23_4-50-56.png

    John
     
  11. DickCappels

    Moderator

    Aug 21, 2008
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    There are connections to the primary which is the thinner wire. The heavy wire with only 10 turns is the secondary.
     
  12. alfacliff

    Well-Known Member

    Dec 13, 2013
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    that is very short wire and a small toroid. unsuitable for 60 hz, more for rf. primary inductrance too low to hold down current, as well as probably wrong core material. try it with a higher frequency.
     
  13. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Have you scraped off the enamel from the wire end regions so that there is proper contact with the breadboard sockets?
     
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  14. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Don't toroidal "transformers" normally have a wound steel/iron band or strap core for 60 - 50Hz? At least any I've seen data sheets on them do. Ferrite or iron powder cores are for high frequency transformers.
     
  15. Reloadron

    Active Member

    Jan 15, 2015
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    That would be my question also. Hard to tell but the AWG 24 looks to be just bare copper wire shorting itself out. While as built it may not be an ideal transformer I would expect to see something on the secondary.

    Ron
     
  16. Roderick Young

    Member

    Feb 22, 2015
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    I like that theory. A quick way to check would be to put the DVM across the 100-turn primary of your toroid while voltage is applied, to see if the voltage is still on the order of 19 volts. If the 10-turn side is connected to 19 volts, I would certainly expect your input transformer to be overloaded.

    Never hurts to re-check with your multimeter, I guess.

    I unwound a toroidal transformer intended for 50/60 Hz. I don't know whether it was ferrite inside - might have been soft iron. If it was laminated strips, I couldn't see it through the paint. http://pididu.com/wordpress/solarbike/deconstructing-a-toroidal-transformer/

    What I noticed in this case is that the 8.5 volt winding had about 130 turns, so you're in the right ballpark, if your torroid is soft iron. If it is, in fact, ferrite, then the inductance per turn-squared is likely to be much lower, and there's an even greater chance of saturating your core. But even if the core is saturating, you should be seeing some output. That's why I like the idea that you're overloading the input supply that Hypatia suggested.
     
  17. ian field

    Distinguished Member

    Oct 27, 2012
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    The ferrite material toroids are made of won't work at 60Hz.

    You need to chop the energising current at say; 20 - 50kHz or so.

    You need a rectifier/reservoir for your 19.8VAC, after that; one of the off the shelf SMPSU chips may be the easy way to go.

    You need to read up on things like flyback, buck and push-pull to determine which topology best suits what you want to achieve.
     
  18. crutschow

    Expert

    Mar 14, 2008
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    Randomly designed transformers seldom work as desired. :rolleyes:
     
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  19. nissan20det

    Thread Starter New Member

    Apr 3, 2015
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    Lol lots of replys wow...lol
    okay yes the bare wire is insulted.
    Yes I did burn enamel off and sanded it down.
    yes the mains where connected when I tested it.
    .178Ohm 24g .4978ohm 30g

    So after I posted this about ten mins later I did get a reading at least. 19.8vdc in currnet draw-2.89347amps. Output 60hz at .0096vdc steping up and .0087vdc steping downsame current draw.. and yes this drops my input voltage to the same as output. So im guessing I need much higher freq.

    Can any of you link me to a simple dc chopper schematic. Possibly using a 555. If you guys think freq is my prob.

    So yes possibly need higher freq.?
     
  20. MaxHeadRoom

    Expert

    Jul 18, 2013
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    If it was it is probably sulking now?:p
    Max.
     
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