the fact that the ATX standard has 12V is really handy in that it makes it easy to replace the PC Speaker in your computer with a real actual car horn

@jk ....wait what


*quickly sharing this outside of masto because THE WORLD MUST KNOW*

@jk josef you don't understand my gremlin brain won't let me rest until i've seen someone do this oh my god

@Nine @jk *doing one backspace too much in the terminal* HOMK!!!

"fucks sake!"

@pettter @jk trying to use adobe software and pressing left-Alt to rescale something only for it to bring up the alt-menu at the top of the window and suddenly "HONK HONK HONK HONK HONK HONK HONK HONK"

@pettter @jk a friend mentioned that Foone might be the person to contact regarding this because it's kinda... sorta a little in their ballpark.


i'm genuinely tempted.


@Nine @pettter as far as i can see, you should only really need the car horn unit (i have no idea how they actually work), a relay, and a diode, resistor and a capacitor (to rectify and filter the PC speaker output into a trigger)

@jk @Nine @pettter consider also: novelty car horns, like ones that play La Cucaracha or go AOOOOOGA

@batterpunts @jk Windshield washer pump, could squirt water at the user
Small cordless tools, could drill a hole in the desk
Windshield wiper motor, could slap the user for their mistakes
I’m pretty sure police sirens run off of the 12v in their cars, unless they use some kind of inverter
Some electric fence systems can run off of a 12v battery to put out ~20KV pulses

@batterpunts @jk These are all terrible ideas. I’d mostly be concerned about the PSU being able to handle current draw from most/all of these devices. You could always have the PSU charge a small sealed lead acid battery, then run the accessories off the battery with a relay. You’d probably have to use a relay on the (5V?) speaker signal to trigger the 12V power from the PSU to run the accessory.

Dammit, I have most of these parts too.

@drewzero1 @batterpunts yeah i was thinking you'd need a relay and an RC filter circuit or something to turn the beep waveform into a relay trigger (maybe a diode too, although i think most speakers are 0V at rest and then alternate between 0 and 5V so might not be necessary?)

@jk @batterpunts I was just wonderingly last night whether my serial terminal’s beep could be more annoying. Apparently, the answer is “yes, extremely.”

@jk @drewzero1 @batterpunts

beware that you need several amps (10A or more) to activate car horns, emergency service sirens etc, and to charge a 12V battery you need 13,8V rather than just 12V.

I have however seen entire PC's that run from a single 12V supply which were made to be installed in cars (this is however about 12 years ago when you didn't already get a multimedia player in most vehicles as standard)

@vfrmedia @jk Ah, I forgot about the higher voltage needed to charge. I know an ATX PSU can supply enough current for a model train motor because I’ve tried, but it makes sense that it would need help with the rest. Drill batteries and automotive electrical systems are beefy!

@vfrmedia @drewzero1 @batterpunts this makes me wonder what the current ratings are for regular, normal, run-of-the-mill PC supplies are usually. i think my 1kW supply could probably handle it, but does your average ~400W PSU assign 120+ watts just to the 12V rail? probably not?

@vfrmedia @drewzero1 @batterpunts based on how many times it shows up on the ATX connector, i'm assuming most of the amps go to the 5V maybe??

@jk @drewzero1 @batterpunts

last time I looked at one most of the power went to the +3,3V and +5V rails, but I've also seen power supplies with a single 12V rails ad 33,3A (although the bulk of this would likely be consumed by the computer, so you would need two if you wanted to run heavy 12V accessories off them)

@vfrmedia @jk @batterpunts Also a good point, I’ve tried running a lot of things off of a PSU but never while also running a computer off the same PSU. And since the PSU’s original purpose is running the computer (go figure!) it makes sense that it wouldn’t have a ton of power left over on top of that.

@drewzero1 @vfrmedia @jk "what other things are 12V", longest thread in history, locked by a mod after 12,583 toots of passionate creative discourse

@jk @vfrmedia @batterpunts I believe so, depends on the PSU and every PSU is supposed to have a label detailing the voltages provided and their respective amperages. I built a bench top power supply out of an old PSU last year and I think I remember the 5V rail having the highest rating, 12V not so much, and -12V having very little.

@batterpunts @jk Most model trains also run on 12V, which opens a whole (small) world of possibilities.

@drewzero1 @batterpunts i'm imagining one of those extremely expensive enterprise tape backup machines that retrieve cassettes from shelves and put them into the drives, except constructed out of model trains which go round tiny looped pieces of track inside the computer case to transport 3.5" diskettes

@jk Stop giving me ideas! I have^h^h^had things to do today!

@jk I have just imagined severs being equipped with this,
And having the beep be used, as one of it's intended purposes, to tell you when a process is finished

Picturing a data-center with cacophony of horns going off has given me the best I've had this year so far

@jk my car horn require several amperes of current to emit noise (4A weren't enough), so I kinda would not recommend it unless you have a good headroom on what your psu can provide

@a000d4f7a91939d0e71df1646d7a48 do you think a 1kw PSU enough? that should have a hundred watts or more on the 12V line, right?

@CobaltVelvet @a000d4f7a91939d0e71df1646d7a48 i just looked up the PSU i'm typing this using and it's also 83A (maybe the same design/components) so good to know i could run quite a few car horns

@jk @a000d4f7a91939d0e71df1646d7a48 as many car horns as needed to reach peak power supply efficiency while beeping

@jk that reminds me, i bought a 1A speaker that's in theory electrically compatible with a PC speaker...

@jk oh no now i have to do this sometime

@jk I have a security alarm thing that is super loud even at 9 volts, I should try this!

Oop just remembered I don't actually have a desktop, just laptops of varying age and SBCs. :(

@jk Protect your users from computer crashes by rigging the PC speaker to an airbag.

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