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FET's Issue 3
- Thread starter zacky
- Start date
Ah yes Scotty, I too love the smell of burning silicon in the mornings !
I have been in and out of the power electronics game for many years. The highest powered switchers I had to design were for charging the pulse forming network of a pulsed solid state laser in the megawatt range. It was all hush hush for the government, so cannot say much about it.
Another rather interesting application for a very high voltage, high power switching power supply actually used a radio transmitting valve, believe it or not.
Later, I was designing really small switching supplies for telecommunications equipment. Another interesting job was designing fairly large no break computer supplies that used ferro-resonant transformers. All interesting stuff.
I have to agree with you, in that what at first looks rather simple, can quickly turn out not to be, and there is no substitute for experience. The only way to get that is the hard way, unfortunately.
I have been in and out of the power electronics game for many years. The highest powered switchers I had to design were for charging the pulse forming network of a pulsed solid state laser in the megawatt range. It was all hush hush for the government, so cannot say much about it.
Another rather interesting application for a very high voltage, high power switching power supply actually used a radio transmitting valve, believe it or not.
Later, I was designing really small switching supplies for telecommunications equipment. Another interesting job was designing fairly large no break computer supplies that used ferro-resonant transformers. All interesting stuff.
I have to agree with you, in that what at first looks rather simple, can quickly turn out not to be, and there is no substitute for experience. The only way to get that is the hard way, unfortunately.
- Thread starter
- #43
I am not sure if there are any good books available. My connection with ferroresonance was when I worked at Sola in Melbourne, and my duties were just the design of the electronics and control system for the beast. The actual ferroresonant transformer itself was an existing design.
You could try looking up the original patents applied for by Mr Sola. I looked through some of those many years ago, there is a lot of very good information contained in there. Apart from that, I have seen very little published information in books. I think they are a bit of a dark secret that not too many people truly understand, it is a rather obscure field.
You could try looking up the original patents applied for by Mr Sola. I looked through some of those many years ago, there is a lot of very good information contained in there. Apart from that, I have seen very little published information in books. I think they are a bit of a dark secret that not too many people truly understand, it is a rather obscure field.
- Thread starter
- #45
Warpspeed, another question please, when it will be a good idea to use Foil coil istead of Wire coil ?
Also, regarding to the wire coil, if all the turns of one layer are shorted together, but we have a good insulation between each layer,does that affect the transformer operation?
Also, regarding to the wire coil, if all the turns of one layer are shorted together, but we have a good insulation between each layer,does that affect the transformer operation?
I suggest you read up on "skin effect". At high frequencies the magnetic field around each wire forces the current to travel only along the outer surface of the wire, along the wires "skin" if you like.
This means you cannot just use a thicker wire to carry more current. The solution is to use a bundle of very thin wires (all insulated from each other), that is called Litz wire. Another often much better solution, is to use copper foil which has a very high surface area.
The design of the magnetics for switching power supplies is a whole very specialised field in itself. One really excellent hard cover book on all of this is:
Switchmode power supply handbook by Keith Billings, published by McGraw-Hill. ISBN 0-07-005330-8
This means you cannot just use a thicker wire to carry more current. The solution is to use a bundle of very thin wires (all insulated from each other), that is called Litz wire. Another often much better solution, is to use copper foil which has a very high surface area.
The design of the magnetics for switching power supplies is a whole very specialised field in itself. One really excellent hard cover book on all of this is:
Switchmode power supply handbook by Keith Billings, published by McGraw-Hill. ISBN 0-07-005330-8
Another excellent book on HF magnetics is 'Soft Ferrites' by Edgar Snelling. It is probably getting hard to find these days. The Ferroxcube databook is worth a look too - it's a free download off their website. Not anywhere near as good as Snelling's book, but useful none the less.
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