tyblu

hey @JasonS, I think I calculated those figures myself based on datasheet values, but I'll look into it further this afternoon.

so Canadian obvs

'cause I kinda like the 'u'

Does english in the Netherlands primary follow British/Canadian (e.g. "favours") or American spelling ("favors")?

How the heck did they get integrated into SE.EE

these embedded CircuitLab schems are amazing.

@Asmyldof TLDR: hook up xfmr to low voltage AC and lick it to see how it works. Or don't. Or do.

I mean, don't lick it. <24V is still okay with dry skin.

also, measure the 12Vac. Should be peak 17V, but it might push that up to >20V without a load, which you should be careful with

just need to make sure the first is 12V alternating current, not DC, because transformers can't do anything with DC

you can shove in 12V ac from another 230Vac in -> 12Vac out and measure voltages without worry

N.A. household is what I call "split-phase" AC, with two 120Vac signals of opposite phase coming in. Can be combined to make 240Vac for larger motors like dryers or ovens, usually used separately for regular stuff.

or "split-phase" output, both AC signals but with opposite phase

center tap is often used to create a positive and negative voltage rail, center tap being ground reference

you can connect single wires/taps from independent coils to create a reference voltage plane (e.g. ground), though

Personally, I wouldn't short any single coil's wires together, as I think that would waste/suck the emf from the core and cause current surges in the shorted wires. But I'm no xfmr genius, so I'm not sure

Not sure. Maybe connect them in series so there aren't floating HV wire stubs. I dunno.

at least for these small power transformers. Don't know about the big ones.

colours are not standardized. Maybe within a company, but I wouldn't even bet on that.

Just imagine that with only a single coil on the input, black/white wires.

The 2 black and white wires in the photo appear to be the only wires going to one side and look like household AC gauge, though, so maybe the output is center-tapped, not the input

(potted with Dupont's 910 plastic stuff)

My first guess is 48V input, 15V output (AC), center-tapped and fused input, potted

It probably means that it has a center tap, and I'd guess that the "PT" means that it's potted.

The output does the same.

nah, a bare coil doesn't care about polarity. You put AC into it, so parity swaps.

If it's on an input coil (may be more than 1 independent input windings) then it's used to choose between input voltages, like between 220V and 110V. If it's on an output coil then it's used to either choose the output voltage, as a 'sensing' wire for a control system (it'll be low voltage/low inductance), or(/and) to power separate parts of a circuit (e.g. analog/high voltage and digital/low voltage).

there's "center tap" ("CT" on diagrams) or simply "tap" which is a wire right in the middle of a winding/coil.

I think my definition of 'tap' is skewed by mechanics lingo (i.e. wrong)

i'll find a picture

its also the wires that aren't the extreme ends of a continuous coil

er, wait

@AndyD273 nah, don't worry about background, just look at schematic of any transformer with multiple taps and coil in/out hookups. They can only get so complicated. A "tap" is just a short coil to detect the field (as opposed to driving it/input power, or receiving it/output power). Used for control systems. Cheap transformers don't have them.

so i choked on a vacuum nanotube in my beer this morning

electronics.stackexchange.com/help/privileges/set-bounties

Oh, the question has to be >48h old.

Used to add a bounty to questions I thought were pretty good but with bad/no answers, usually because it was a difficult question, but I can't figure out how to do that anymore.

Can I just not find the 'add bounty' link/button that used to be on a question for those users with sufficient rep, or is it gone, or was the rep limit raised above mine? (6ksomething)

best

@Asmyldof Are you asmyldof.com?

er that didn't work.

Yeah, just like this :38136215

@W5VO isn't that every grad student's dream?

@AndyD273 you can probably figure out which order the coils are in relation to the wires just by measuring resistance with a good meter, as it'll be ~0.1-1'ish ohms. The tap wires, if there are any, won't be measurable (they're too short) without a great meter (eg. 4-wire, fancy Fluke, etc)

It sounds like you're looking for a way to test your program. Maybe look at writing a script for the VM to run to send, receive, then do something with the received audio (e.g. with a built in BT stack, it could send it to your computer/phone for further analysis).

@user17915 Probably not. Looking at a link that Google found for me, it looks like the DSP gets the audio independently from the VM, but I doubt that it takes care of the Bluetooth pairing/stack. I bet the VM does that.

@W5VO Hey W5. Are you tenured, yet? ;)

I 'suppose that's not what you're talking about.