...And the successful completion of a migraine later (oh! Aura! Not to mention prodrome), things are lookin' up. The Big Secret Project is (essentially) complete and will be unveiled Monday or Tuesday and even Evil Boss unbent enough to make today's OT optional rather than mandatory. Me, I have thus far passed on it (see opening sentence) but may yet go in to catch up on tasks left undone while the push was on.
I may even be able to post before & after photos of the work.
And, for anyone who needs to run a big 240 Volt appliance on 110, allow me to point you at the nifty big toroids Digi-Key sells. They are definitely in the "assembly required" class but after running a 3000 VA (call it 3 kiloWatts) version for a week, I have been very happy so far. Mind you, that's big enough that it's not a wall-socket application on the primary side -- it takes a 30 Amp breaker and fat #10 wire. --For hobbyists with less heavy-duty applications, I have long been of the opinion that toroidal iron is the best way to go unless low cost is the prime requirement. For only a little more than the price of conventional iron, you get less volume, less stray magnetic field, lower core losses and better inherent regulation with varying loads. What not to like? They're even good for audio -- Western Electric's legendary 111C repeat coil, which offers specs to make audiophiles swoon, is a toroidal transformer. (N.B, WeCo never claimed any better flatness than zero dB change between 30 cycles to 15 kc/s but real-world response far exceeds the spec). Besides: donuts. Mmmmm.
BUILDING A 1:1 BALUN
6 months ago