High frequency current source lighting?

Hello,

Suppose i have a load of LED luminaires that i want to light from a power supply.

I can do it with a voltage source power supply, and have current regulators connected up to the voltage bus.....................OR

I can have a high frequency (50KHz) sinusoidal AC power CURRENT source, and simply couple the led luminaires to the power bus via current transformers.

The current source way means having completely waterproof connection.........as opposed to the voltage source way, where lots of non waterproof connectors would be used.

So, do you think this is a viable proposition?.......and if so, what steps would you take to assure a good power factor in the current source bus?

 

Yes thats right....but that way of doing it is less waterproof...........using a high frequency current source power bus, and coupling into it with couplers which supply the luminaires is a very waterproof way of doing it....do you not agree?

The bus wire just gets hooked into the coupler, theres no "connection" for water to run into.

 

If i told you that you could get a strand of insulated wire (not coiled), make 50KHz sinusoidal current flow in it from a generator..........and then hook a resonant inductive coupler over the strand of wire, and couple 50W out of the strand of wire, and use it to light a LED luminaire with the 50W, would you say that this was feasible?

.....the coupler being 97% efficient, and from a fixed sinusoidal current flowing in the strand of wire, the coupler is made so as to produce a specific current level in the LEDs.



...so is this just boring, old , everyday stuff?, or simply not feasible?

 

Thanks JimW..........you're saying what i've been thinking......but i'm slightly different because i've seen this thing working................i saw him hook the coupler onto the straight wire and the lamp lit up.....................it all happened quickly, and i couldnt say if it was 50W 's worth of LED light...................i'd say it wasn't.....but maybe that particular coupler was only one of their low current couplers......

On the website of the company, they have a 57W LED lamp being lit like this.....and they say that you can hang up to ten of the 50W lamps off of a straight wire if the 500W current source is used.

I wouldnt believe it, but a representative of one of our customers came in to get the system hooked up in his company so they could use it and see if they like it..i happened to know the guy, as he was an ex-boss from a previous place.........so these systems are being sent to customers now.

So i would ask, how do they get the density of flux to be so high around a single strand of wire?...................are they using special, very expensive ferrite material?

....but i speak to all about magnetic induction...............Faraday told us that we can transfer energy via magnetic fields providing there is cutting of flux.............in order to get enough cutting of flux lines, you need to get the flux lines to be dense......but how do you get dense flux around a single straight strand of wire?........the normal practice is to coil the wire so as to get the MMF up, and increase the flux density........but the "primary" here is just a straight peice of wire, so how do you get the flux to be dense enough?


Lets speak further...............imagine one of those AC current clamps that you get...where you grip it round the straight strand of insulated wire carrying AC and you measure the current in it.........well now picture something like that, where you grip it round the straight piece of wire, and then you are able to couple enough power out of the straight piece of wire to drive a 50W LED luminaire..............

.....if that seems "everyday" to you, then please tell me why?...........that is revolutionary................and i've seen it with my own eyes.

so its a question of flux density...how do you get it so dense around a straight piece of wire?

 

....they have it in writing, and on demo videos on their website...........their website is out there for all to see....but i doubt you will find it...........i tried to find it without using the company name.............and it ended up being a not so technical search term which got me there.

...that guy was my ex boss, we were amicable, but not matey, if you know what i mean...i couldnt just phone him up

......i suspect that they're using a very expensive type of super high permeability ferrite, one that keeps the field in the ferrite, or very close to it only.......

.....i said it's a single strand of wire, and it is, its a loop of wire (a short) which is connected to the output of the 50KHz sine current source.......but they twist it together so that there's not a big loop area...............

On our competitors website, it shows them literally sliding the led luminaires onto the single strand of insulated wire, and then their leds light up......with the led lamps literally lit up whilst sliding along the insulated wire.......but we twist the wire, but i think the twisting is just to reduce emc from switching harmonics of the 50khz current source.....i.e. reducing the loop area...................

i couldnt be sure if they are using the 'go' and 'return' or just the 'go'..........they certainly hook both of them in to the couplr slider, but i think they only hook both for mechanical stability..................i dont think theyd use both 'go' and 'return' as surely their fields oppose and cancel each other out?