Post B6CPc5965dWcIqWH9E by tyler@nicecrew.digital
(DIR) More posts by tyler@nicecrew.digital
(DIR) Post #B6CPUZH8BX3vQoh6yO by tyler@nicecrew.digital
2026-05-11T17:47:33.896429Z
3 likes, 2 repeats
someone send this to rehr
(DIR) Post #B6CPc5965dWcIqWH9E by tyler@nicecrew.digital
2026-05-11T21:07:00.349152Z
0 likes, 0 repeats
I think you are smart buddy, your job is something I've never been any good at whatsoever despite trying very hard. Very skilled frogman .
(DIR) Post #B6CPkFbH6Wil2lavJo by tyler@nicecrew.digital
2026-05-11T18:24:45.916187Z
0 likes, 0 repeats
I'm not looking forward to trying to limit EMI when i put panels back up
(DIR) Post #B6CPkGeVC0teJ470zI by JollyR@nicecrew.digital
2026-05-11T20:46:59.966582Z
1 likes, 0 repeats
In the 90s, I interviewed for a job at a company that makes industrial UPS systems. Three phase, 480 volts, 3/4 of a megawatt. Keep a factory going for an hour or two off grid. They kept the inverters running all the time and routed all power thru the UPS to avoid any switching transients. And were working on a system to route any in-house excess power back onto the grid... All digital controls. Anyhoo, the chief engineer there was designing correction factors out to the 5th harmonic & beyond. Using designer transformers, wound in house with Litz wire, some kind of special low-hysteresis iron alloy core. Switching transistors the size of bricks, mostly made of thermal compound. He was trying to get better than the industry accepted 92% efficiency out of the thing. Would've been an interesting job, but they didn't make an offer. It was fun to visit the plant, however.
(DIR) Post #B6CPkHDx4DFk50hKF6 by tyler@nicecrew.digital
2026-05-11T20:57:46.085732Z
0 likes, 0 repeats
Yeah that sounds sick. I don't really know what I'm going to do about it yet.Maybe design a custom low pass filter box for a few khz or something. I'd have to figure out the mppt polling rate so the controller could still function though. The inverter makes noise too but it's a bit more tolerable. The charge controller screams like crazy
(DIR) Post #B6CPkI3Lz6MyeQkNMW by JollyR@nicecrew.digital
2026-05-11T21:03:43.647420Z
1 likes, 0 repeats
Yeah, there's a difference between a sine wave with teeny tiny stair-steps on it, and the uncontrolled fuzz of a pwm switching function...
(DIR) Post #B6CU7qETTKvD8LQz7Q by JollyR@nicecrew.digital
2026-05-11T21:53:34.953180Z
1 likes, 0 repeats
Now that I think about it, I don't know how the UPS company controlled the harmonics. They must have been able to fine-tune the timing and amplitude of the correction signals, while those big ass igFETs had to strictly avoid operation in the linear range so they didn't overheat. I saw the remains of some igFET bricks they had exploded. I got a lousy grade in my linear networks class (didn't like the professor) (when slide rules were being replaced with primitive hp calculators) but I'm pretty sure that if you slam a square current pulse into an analog circuit, the result is predictable. But how the company linearly combined 180Hz and 300Hz into the output with >92% efficiency I do not know. The whole system was singing like a struck anvil at about 6000Hz, and the engineer said it was magnetostriction in their handmade transformer cores, and the cause of some lost efficiency. He was exploring different geometries and alloys for them.
(DIR) Post #B6CU7rLFLdvuZdbuJU by tyler@nicecrew.digital
2026-05-11T21:59:41.039055Z
0 likes, 0 repeats
That sounds like a really fun job