nyeboy2000 said:
Can you tell me more about SMPS? What is the price range for something like that? What else would I need as far as fuses or other? Also more about any possible safety concerns. I really appreciate all of your info. Thanks.
SMPSes are power supplies that convert the incoming AC into DC and step it down.
Avoid naked PCB power supplies if you can, there is 170v on the bottom of the board(340v if 240v). :shock:
My friend Caitlin Williams got a shock from an unplugged fluorescent lamp that caused her to wet herself. :lol: :lol:
The cap in the lamp is only 220uF.
I have seen 2 680uF caps in a dell power supply.
BTW, I reverse engineered an old dell power supply from a p133.
That dell power supply used a LITEON power transformer(at first, I thought they only made CD-ROM drives).
There is only one switching transistor(well, only one big primary transistor, as there is a smaller transistor in the 5VFP supply, and several big transistors on the secondary side), but it is a high-power IGBT boobie(20A, 900v) in a TO-3 case.
The primary caps are 680uF each, for a total of 1360uF(most PC power supplies have only 2 470uF, or 940uF total)!
The coil in a flyback regulator cannot be called a true transformer.
My friend Christina Mahoney designs SMPSes alot, and she said that a true transformer has instants where power is going in and out at once, but the coil in a flyback converter never has an instant where power is going in and out at once.
When the transistor is on, current flows through the primary winding, and energy is stored as a magnetic field in the core.
When the transistor turns off, energy flows out of the core into the secondary circuit.
In other words, it is like using a cup to transfer water from one container to another.
She also explained the switching frequency.
Higher frequencies allow higher power density, because power goes into and out of the coil faster(back to the water analogy: it's like filling the cup and emptying it faster, so a smaller cup can be used).