50KHz Power bus is OK..?...Yes 50 KiloHertz

[Flyback]

Ugh (-_-), so then it's not wireless lighting?

I dont know what you mean by "wireles lighting"..sorry....its wireless in that there is no metal to metal contact in connectors when the light is "plugged in"....and this means its waterproof...............its a connection by magnetic field.

...nobody else anywhere in the world seems to do it..so i guess its quite new.

 

[ronv]

Doesn't it defeat the purpose if you hook something up to the receiver for dimming? I guess you could use something like a tv remote and power that receiver from your circuit.

 

[alec_t]

nobody else anywhere in the world seems to do it..so i guess its quite new.

Seems to me to be just the use of a transformer having a single-turn primary. Surely not new? The same principle is used in current transformers the world over. I'm not convinced that C1 does anything useful. As others have said, it would be better used (across the LED string) as a smoothing/reservoir cap.

 

[()blivion]

I'm not convinced that C1 does anything useful.

Agreed. If it's just a normal transformer then yes, It doesn't do squat in the sim from what I have seen.

 

[Flyback]

as ()blivion pointed out............this is no normal transformer...this is a "resonant inductove coupler"...........its high science, schematics of which i am not invited to see....................maybe the R.I.C. has a current transformer at its output to buffer it from the led load?...what do you think?............i unfortunately do not know........i wish i did know, becasue when i am designing someting for a system, i like to know a bit about the system first.

as you know, i am trying to design a 50KHz phase cutter for the output of the R.I.C..so that the leds can be dimmed............and each individual R.I.C. has a different available current range

 

[ronv]

I don't know much about power factor correction, but I think that is the purpose. If you look at the sim without the cap the peak current occurs at the peak voltage as with the cap it is a nice sine wave with voltage and current nearly 90 degrees out of phase.

 

[Flyback]

ronv.

If you look at the sim without the cap the peak current occurs at the peak voltage as with the cap it is a nice sine wave with voltage and current nearly 90 degrees out of phase

..dont you mean that the other way round?

 

[ronv]

Nope. Look at the primary.

 

[Flyback]

i just ran your sim again......the led current doesnt look right..it looks too "gappy"......the primary source is a current source, and not a voltage source.the primary current should be nothing other than a 50KHz sine......sorry , but your sim is irrelevant to this project.

 

[()blivion]

sorry , but your sim is irrelevant to this project.

Ronv knows his electronics. Probably more so than I. Respect be given unto him, he is worthy of it.

My sim
I have attached my sim to this post. You will note that there are some subtle but important points that my sim addresses.

1) The energy being supplied to the circuit is, without a doubt, a sinewave current source. Not a voltage source.
2) I changed the coupling directives so that L2 and L3 are tightly coupled, while L1 is only loosely coupled to them.
3) I lowered the inductance of the secondary. I made the secondary's inductance resonant with C1 for the indicated frequency.

Note that even with these changes, the sim is still quite unrealistic. This is because the loose coupling brings back the old problem of needing ridiculous voltages to make current flow through L1. At times in the sim I was seeing 4KV on L1. I don't think LTSpice knows how to do loosely coupled transformers well enough to accurately simulate the kind of circuit we are(I am) claiming this is. And I don't know how, if it's even possible, to set the current source to have an upper limit to it's voltage. I suppose I could cheat and use some kind of regulator circuit, but I'm far to lazy to even try to do that right now.

The mystery of C1.
If C1 does anything useful in that configuration, it is power factor correction. That is really the only thing it could be. It doesn't serve as a usable filter, and it is not some kind of delay. The only thing it does is form part of a LC tank with L2+L3. As to exactly how it corrects power factor when configured like this... we all have our opinions.

There is more to this story than we are seeing, I'm fairly sure better performance with a more realistic system can be had than what is shown in my sim. It's probably a simple matter of doing as I said before and making L1 part of a power oscillator running at 50Khz, rather than running the current source to it. If it's not that, then L1 needs a cap across it that makes it resonant, or the inductance needs to be lowered. I believe knowing more of the critical parameters, especially the transformers specs, is necessary to continue on any farther with a current source powering the primary.

Edit: OK, NOW I have attached my sim file.

 

[ronv]

Why thank you ()blivion.

I give up on this one.

 

[Flyback]

Ronv knows his electronics. Probably more so than I. Respect be given unto him, he is worthy of it.

...thats why i already apologised to Ronv..because the reason Ronv used a voltage source was because i had not told well enough that it was all supplied by a current source. The normal way to do this is with a voltage source, and its only normal to do it like that...................this project is an absolute one off, so its difficult for me to explain, but in return, makes it more novel.....................

..........................i'm sure you'll agree that having a 12 foot length of twisted pair wire, and coupling 250W worth of LED luminaires out of it, simply by hooking "couplers" through bits of the wire of the twisted pair is the stuff of sci-fi movies.....................i am still not sure of my employer is BS'ing me here...and thats part of the reason i'm on this forum..................it was only whan yourself ()blivion pointed out R.I.C.'s that i realised that was the technology at play here...........................................i only worked on the emergency light part, which is plain electronics.....but now they asked me to do the dimming rectifier, so i try to understand the bit about R.I.C.s...............

picture in your mind a plain bit of twisted pair wire..............and then imagine hooking an individual coupler through a bit of it, and it supplies a 40W led luminaire from the coupler.................wow.................................as i said, this is what these guys say theyre doing.........................i saw him hook up a luminaire to the twisted pair and it lit.......but it was broad daylight , and i couldnt ascertify if it was 40W worth of light in the few seconds that he kept it working before switching it off.

()blivion thanks for sim.asc.

i ran it, and who knows that may be like it is.........but i think the current on the way to your C1 is a bit too "jagged"..........when i was doing the battery charger bit, which runs off the battery charger R.I.C. , he told me the current was "all very smooth here".....and thus told me to take out the LC filter that i'd put in.

so you used a 1m primary.....and maybe it is for all i know............maybe there is some very very expensive ferrite type that theyre using which gets it that high.

i am still wondering of there is a current transformer buffer between the R.I.C. and the load?

i'd think this project was BS if i hadnt already seen a customer (who is a guy that i used to work with somewhere else) come in as a representative of a big lighting company and speaking of installing the system at his companies HQ.

................coupling 40W out of a bit of twisted pair..............and having up to 12 of these hanging off a 24 foot bit of twisted pair....this is doing my head in...........on another forum, they've told me its not possible.........

 

[blueroomelectronics]

...thats why i already apologised to Ronv..because the reason Ronv used a voltage source was because i had not told well enough that it was all supplied by a current source. The normal way to do this is with a voltage source, and its only normal to do it like that...................this project is an absolute one off, so its difficult for me to explain, but in return, makes it more novel.....................

..........................i'm sure you'll agree that having a 12 foot length of twisted pair wire, and coupling 250W worth of LED luminaires out of it, simply by hooking "couplers" through bits of the wire of the twisted pair is the stuff of sci-fi movies.....................i am still not sure of my employer is BS'ing me here...and thats part of the reason i'm on this forum..................it was only whan yourself ()blivion pointed out R.I.C.'s that i realised that was the technology at play here...........................................i only worked on the emergency light part, which is plain electronics.....but now they asked me to do the dimming rectifier, so i try to understand the bit about R.I.C.s...............

picture in your mind a plain bit of twisted pair wire..............and then imagine hooking an individual coupler through a bit of it, and it supplies a 40W led luminaire from the coupler.................wow.................................as i said, this is what these guys say theyre doing.........................i saw him hook up a luminaire to the twisted pair and it lit.......but it was broad daylight , and i couldnt ascertify if it was 40W worth of light in the few seconds that he kept it working before switching it off.

()blivion thanks for sim.asc.

i ran it, and who knows that may be like it is.........but i think the current on the way to your C1 is a bit too "jagged"..........when i was doing the battery charger bit, which runs off the battery charger R.I.C. , he told me the current was "all very smooth here".....and thus told me to take out the LC filter that i'd put in.

so you used a 1m primary.....and maybe it is for all i know............maybe there is some very very expensive ferrite type that theyre using which gets it that high.

i am still wondering of there is a current transformer buffer between the R.I.C. and the load?

i'd think this project was BS if i hadnt already seen a customer (who is a guy that i used to work with somewhere else) come in as a representative of a big lighting company and speaking of installing the system at his companies HQ.

................coupling 40W out of a bit of twisted pair..............and having up to 12 of these hanging off a 24 foot bit of twisted pair....this is doing my head in...........on another forum, they've told me its not possible.........

Rubbish. I don't believe a word of it.

 

[Flyback]

Rubbish. I don't believe a word of it.

what dont you believe?
Surely you see that their will be coupling with the 50KHz AC , to the secondary.........regarding losses, well, core losses...thats not much as its only 50KHz, windinf resistance.....thats not much.....what is the loss factor thats so big that you think this is rubbish?

 

[Mr RB]

How many SMPS transformers have you designed and tested? Things that really hurt efficiency are if the primary has very low turns, or the magnetics are poorly coupled ie air coupled, or change in air gap.

Pretty much all those worst case conditions occur here.

 

[Flyback]

primary has very low turns

...i think its needed to consider a current transformer, where theres only one turn on the primary, and 100 or so on the sec...and yet the coupling is excellent.

 

[KeepItSimpleStupid]

ST & Flyback - Pop up blocker may be interfering. Try stuff like open in new windpw etc.

 

[blueroomelectronics]

...i think its needed to consider a current transformer, where theres only one turn on the primary, and 100 or so on the sec...and yet the coupling is excellent.

BS
Why are you pursuing this? Do you have this circuit or a working iSotera on your desk? If so open it up and post a photo. You appear not to have the skills to understand what's involved which makes this tedious and bizarre. You're also not very forthcoming, what are you not telling us?

 

[Flyback]

Though please can you explain why the coupling shouldnt be super efficienct? What skills do you mean?....its just magnetic coupling by flux cutting...same as any other transformer
(i am in Belgium, but i am not from here..ref qu from other post.)

 

[blueroomelectronics]

Your skills, they don't appear to be up to the task. You claim you're evaluating a product but you're not very objective, it seems like you're endorsing it yet you don't understand it and can't even answer the most basic questions about it.

Have you ever seen a transformer that uses a single conductor going straight through? No winding?

In some posts you claim to be developing an emergency light with NiCAD batteries and a SAM3 CPU (why who knows), in others you're reviewing iSotera yet appear to be more interested in reverse engineering it. You'll ask about voltage references but seem to disregard any member advice that does't jive with your understanding.

Do you have a iSotera coupler or supply. Can you answer that simple question?