I want to ask if we have a modern source of good quality 22V x 2, 300-400VA transformers today? I would like an additional insulation layer between the primary and secondary, if possible.
The Hammond 167 series https://www.hammfg.com/electronics/transformers/power/167 is the only transformer I can mention here, but not 2x22v….
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Thank you so much for taking the time to reply! I’ll have a look.
Viewing their datasheet schematic, the secondary is center tapped (C.T as they label it). I take it that indicates 22V C.T is “11V-0-11V”, or am I mistaken here?
Viewing their datasheet schematic, the secondary is center tapped (C.T as they label it). I take it that indicates 22V C.T is “11V-0-11V”, or am I mistaken here?
Triad makes those split bobbin transformers too, and may have a decent size 44VCT. The quality isn’t bad, but the regulation is poor. Difference between no load and full load is like 20%, even for the big ones. Concentric EI will do better, but nowhere near the hi-pot capability.
YOU are correct, the transformer in the picture is 70V CT,
you have to contact them for the 44v CT. They are already kind of expensive, I can imagine that the custom ones will be at least double,
But why the EI transformers?
Part of my goal is to avoid the hum that I’ve had with toroidal types (different application). A DC blocker can remedy the prime symptom, but I had hopes of just using an EI type and keeping it relatively simple from the start.
The “ real” toroidal audio transformers are designed for lower magnetic flux density in the steel core to reduce mechanical hum.
Piltron and Toroid and other North American companies can provide such transformers.
Piltron and Toroid and other North American companies can provide such transformers.
High line at 50 Hz will make a toroid buzz when it won’t do it in the states.
It will make IEs noisy too.
It will make IEs noisy too.
Talema/Nuvotem make silent toroids even for development countries with 50 Hz 230V grids. Their name in English speaking countries where people like to buy locally produced stuff 🙂: Amveco
https://hubbellcdn.com/ohwassets/HCI/Acme_Electric/Literature/SECTION-10.pdf
https://hubbellcdn.com/ohwassets/HCI/Acme_Electric/Literature/SECTION-10.pdf
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Yes that are +10/-6% tolerance 230V 50 Hz grids. It makes sense to have 240V specced transformers as voltage only goes up.
Mechanical hum with relatively recent stuff is mainly because of a small DC component in the mains voltage.
Mechanical hum with relatively recent stuff is mainly because of a small DC component in the mains voltage.
Between the DC for all those rectifier loads on the grid and lines running 254 volts, most older transformers make a lot of racket these days.