Build a Robust 50V Dual Rail SMPS Complete Guide with PCB Layout Gerber Files

Alright, let’s break this down—no boring textbook language, just the real deal. So, you want to crank out a ±50V dual-rail SMPS using the KA3525A chip? Sweet. That’s the kind of juice you need for beastly audio amps or maybe a bench supply that doesn’t flinch at high power. Here’s how it rolls: First off, why bother with this setup? - It’s crazy efficient. The green ferrite core? That’s not just for looks. It chews through high frequencies without sweating losses. - You get a proper dual-rail output: +50V, ground, 50V. Perfect for those power-hungry amps. - Want to tweak the output voltage? Just mess with the secondary windings—longer wire, higher voltage. Easy peasy. - Gerber files are already done for you. Just send ‘em to your PCB guy and you’re golden. Parts List—don’t start until you’ve got all this junk on your bench: - 102pF, 50V cap (one) - 103J cap (one) - P55NF06 MOSFETs (six) - KA3525A IC (one) - 6A4 diode (one) - 1N4007 diode (one) - HER308 15A diodes (eight—yeah, a lot) - 15Ω, 1/4W resistor (six) - 2.2k, 1/4W resistors (two) - 12k, 1/4W resistors (three) - 100Ω, 1/4W resistor (one) - 1000μF, 25V caps (two, chunky ones) - Ferrite core for the transformer, 50 mm size—don’t cheap out here Now, about that transformer. This is where the magic happens—and where most people screw up. You’ll need a green ferrite core, 50x20x10 mm, high permeability, low loss. For the primary (input side, 12V), use 20AWG wire. Wrap four pairs, each 18 inches. Keep the ends together, but don’t connect them yet. For the secondary (output), the same gauge wire, but three pairs, 74 inches each. Ends together again. If you’re feeling lucky and want more volts, just go a bit longer on that secondary—like, 80 inches. Pro tip: slap on some varnish after winding so the thing doesn’t buzz like a cheap electric toothbrush. And keep it tight, or your MOSFETs will get toasty. Speaking of heat—don’t just slap those MOSFETs onto any old heat sink. You need two, 35 mm wide, and keep a 3-5 mm air gap between them. Q1-Q3 on one, Q4-Q6 on the other. Don’t short them, unless you like the smell of burning silicon. PCB assembly? Start with the big boys—the HER308 diodes and the MOSFETs. Use fat traces for the primary and secondary. Skinny traces are for chumps. When you’re ready to fire it up, use a 12V/1A supply first. Don’t just jam in a car battery and pray. Measure your output—you should see ±50V with nothing connected. If not, something’s wonky. If anything gets hotter than your morning coffee, check those windings and your MOSFETs. Insulate, tape, whatever it takes. This rig’s awesome for class AB/H amps, bench supplies, and even industrial stuff if you’re that kind of nerd. The ferrite core lets you switch at 200-500 kHz, so you get a small size and top efficiency. And hey, if the output goes south, recheck your transformer joints and MOSFET gangs. Nine times out of ten, that’s where things go sideways. Ready to roll? Grab the Gerber files and schematic here: Download Gerber. Go build it—honestly, it’s as solid as any store-bought SMPS. Stuck somewhere? Drop your questions in the comments, no shame. *Keywords: SMPS circuit, dual-rail power supply, KA3525A design, ferrite core transformer, ±50V SMPS, PCB Gerber files, DIY power supply, high-voltage converter, audio amplifier PSU*