Safety advices before experimenting with these circuits

[spec]

Spec, I was waiting for your post on this topic, had this feeling you'd join too. Phew, you really put effort on your posts

Thanks fezder,

It is a good job you and the others warned the OP. When I read this post it put shivers down my spine- when I was around eight I came pretty close to electrocution doing a similar thing. It was only by luck that my mum happened to come into my den and turn the mains switch off- I could not let go. That put an end to any electronics for me for a long time.

spec

 

[fezder]

I have a small transformer with a laminated steel core. The configuration was similar to the setup I was trying, so I thought that using the toroid core would be very similar. But no.

If you mean that transformer on post #1, measure primary side resistance, and compare it to your transformer you made. Also, that core you used, is much smaller and it saturates sooner

 

[fezder]

It was only by luck that my mum happened to come into my den and turn the mains switch off- I could not let go. That put an end to any electronics for me for a long time.

Phew, lucky!. Some folks wouldn't use any electronics after such incident at all.

 

[spec]

I have a small transformer with a laminated steel core. The configuration was similar to the setup I was trying, so I thought that using the toroid core would be very similar. But no.

The laminated steel core is a soft magnetic core?

Laminated steel cores have a high inductance for every turn of wire. So why use anything else you may wonder. The answer is frequency.

Laminated steel cores are only effective at low frequencies, say up to 1KHz for power transformers. After that they are so lossy that they are useless. Ferrite, on the other hand, has a much lower inductance for each turn but it will operate up to 10Mhz for a power transformer, as used in a switch mode power supply (SMPS) for example.

spec

 

[spec]

Phew, lucky!. Some folks wouldn't use any electronics after such incident at all.

Yeah, it scared me and my mum went mad. You will never guess what I was trying to do- perpetual motion. I had a carefully worked out invention where a motor drove a dynamo which in turn drove the motor again. If it hadn't of been for the accident it would have changed the world.

spec

 

[fezder]

Already that young you were trying to make free-energy?

 

[Tony Stewart]

I am experimenting with electricity and I know it's dangerous.
I have some different questions that I will ask one by one.

I want to check if these tests are safe. Lets start.

I have a small transformer rated :

• It doesn't matter how I connect the input? I mean if I want to connect the live wire. Can it be connected in the top left connection or top right connection?

If you learn how they work, then you can answer your own questions.

Given specs:
Input 230V~
Output 12V~ 0.3A

Hence output = 12V*0.3A = 3.6 VAR or 3.6W with a linear load = 12V/0.3A = 40 Ohms thus for 1% loss on secondary copper wires , output DCR=~0.4 Ohms ( which you can measure with ohmeter)
Also turns ratio = 230/12 = 19.2 at rated load.. I would a higher ratio like 20:1 since I simplified the analysis without losses.

The part that may be new to you is that the inductance of primary is much higher than the secondary for 20:1 and can be estimated by the N squared turns ratio.
Thus if you connect in<>out backwards The input impedance of the secondary coil is now 20*20= 400 times lower and your no load input current with 230V on the secondary is now 400 times bigger. This ends up saturating the magnetic limits of the core and then the impedance drops even further rapidly, so line voltage ends up seeing a the secondary impedance as a load now dropping towards simply the DCR of the copper ( DC resistance) thus you get 230V/(0.4 Ohms + 2*pi*50Hz*Lsaturated) = lots of amps. poof.

~ the end ~
To inductively connect both windings all transformers need a magnetization current of around 8~10% of full load rated current. THis is load independant but depends on transformer Voltage and INput inductive impedance I=V/ZL where ZL = 2*pi*f*L is the inductive impedance.

 

[spec]

Already that young you were trying to make free-energy?

It's the other way around. It was because I was so young that I was trying to achieve perpetual motion. When someone told me it was impossible, I knew better.

(It's quite funny when you get OPs effectively trying to do the same thing. I bet they think that we don't know what we are talking about either.)

My dad was an electronics enthusiast and a mechanical engineer so I grew up with wire, solder and flux.


spec

 

[dr pepper]

This is a very good webpage if your interested in ferrites.

https://www.dos4ever.com/flyback/flyback.html

You might be able to get that ferrite to work at 50/60hz, its just that you wont be ustilising it well.

You dont have enough turns on the core, at a guess I'd say 40 to 50 turns, it depends on the ferrite, power ferrite would be less.

Care is still needed at the mains side of the transformer, hopefully your using an ac bench supply.

 

[audioguru]

When I was young I made rockets and bombs. All my rockets blew up and all my bombs flew very high. I also made an iodine compound that blew up spontaneously when it dried. I think it is rocket fuel today. Luckily I still have all my fingers and toes.

 

[spec]

When I was young I made rockets and bombs. All my rockets blew up and all my bombs flew very high. I also made an iodine compound that blew up spontaneously when it dried. I think it is rocket fuel today. Luckily I still have all my fingers and toes.

Hi AG,

Me too: a mixture of potassium chlorate, sulfur, and charcoal for both bombs and rocket fuel. I even had a go at making nitroglycerine- thank god it just caught fire

It seems unbelievable now, but in the late 1950s a school boy could buy eight ounces of potassium chlorate over the counter from the local chemist and as much sulfur and charcoal as he liked (but not at the same time). Once the chief chemist asked what the potassium chlorate was for: making oxygen for home study in chemistry.

spec