Help cant get homemade toroid to work

Thread Starter

nissan20det

Joined Apr 3, 2015
69
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
 

t_n_k

Joined Mar 6, 2009
5,447
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.
 

ScottWang

Joined Aug 23, 2012
6,829
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.
He is not connected directly to the Mains -- Powering with 120v A/C (U.S.A.) transformed to 19.8v A/C 60Hz.
 

Hypatia's Protege

Joined Mar 1, 2015
3,197
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.???View attachment 84458
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:

alfacliff

Joined Dec 13, 2013
2,458
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.
 

shortbus

Joined Sep 30, 2009
7,078
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.
 

Reloadron

Joined Jan 15, 2015
4,578
Is the 24 gauge wire insulated?
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
 

Roderick Young

Joined Feb 22, 2015
408
The (toroidal transformer's) primary reactance may be so low at 60hz that he is effectively 'shorting out' his power supply xfmr...
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.

Have you scraped off the enamel from the wire end regions so that there is proper contact with the breadboard sockets?
Never hurts to re-check with your multimeter, I guess.

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.
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.
 

ian field

Joined Oct 27, 2012
6,540
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.???View attachment 84458
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.
 

Thread Starter

nissan20det

Joined Apr 3, 2015
69
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.?
 
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