Electrical Engineering V3 - Developers

Just spend £200 on a £3000 Power supply that is broken.... Hope I can fix it! TDK.Lambda PSU, 600V 0-5.5A [editline]2nd March 2015[/editline] [url]http://www.conrad-electronic.co.uk/ce/en/product/511618/TDK-Lambda-GEN-600-55-3P400-rack-mount-programmable-power-supply-Synchronised-0-600-Vdc-0-55-A-33-kW-Rack-ins[/url]

[QUOTE=Chryseus;47238718]Yes it will be 24V AC out, if you use a bridge rectifier and filter it with a cap your peak DC voltage will be around 24V * sqrt(2) = ~34V. 6VA is the same as saying 6W max. At 6V this is 1A. At 12V this becomes 0.5A max. At 24V 0.25A max. Do the math and you see they are all 6W. As for what value cap you should use a general rule is 10,000uF per amp, depending on how much noise you can tolerate anywhere up of 1,000uF per amp is usually perfectly fine, in your case I'd use 470uF 50V. You pretty much need to double this for half-wave rectifiers or full wave center tapped rectifiers (2 diodes). Rload simply means the load you connect it to, represented as a resistor.[/QUOTE] VA is slightly different than Watts though. VA is the apparent power consumed by the load, more specifically Vrms * Irms. If you have a highly inductive load you may be using 6VA but only consumer 3 or 4 watts of power. The term for this is the power factor which is a dimensionless ratio of the real power vs apparent power. This comes from cos( phase angle) where the phase is the angle between the voltage and current. EDITED for corrections

So I pulled the guts of a rear projection set out of the woods a few weeks back, dismantled and washed it all. Reassembled it today and plugged it in. [IMG]http://i11.photobucket.com/albums/a166/ballsandy/IMG_8407.jpg[/IMG] [IMG]http://i11.photobucket.com/albums/a166/ballsandy/IMG_8400.jpg[/IMG] I don't have a better way to hold it and its 24Kv goodness but I can see through the tubes VIDEO 1 so we're in business! :dance: Now I just need to find a cheap 70's coffee table to fit it in, or I'll have to go and build my own cabinet. [img]http://4.bp.blogspot.com/-5ZKcZjr7Kfg/UY0o3Pgr8kI/AAAAAAAAIPY/RhRW9wGMUJk/s1600/vintage+70%27s+coffee+table+tiki+doors-2.jpg[/img] It does however have one weird bug. When in standby all the voltage rails pulse between their ratings and 0v. All I can assume is a cap has drifted out or a transistor is leaky so it's not really going into standby but you can still wake it up from the power button and it stays on.

[QUOTE=Dolton;47244741]VA is slightly different than Watts though. VA is the apparent power consumed by the load, more specifically Vrms * Irms * cos( phase) where the phase is the angle between the voltage and current. If you have a highly inductive load you may be using 6VA but only consumer 3 or 4 watts of power. The term for this is the power factor which is a dimensionless ratio of the real power vs apparent power. This comes from cos( phase angle) .[/QUOTE] I think you might have mistyped, apparent power is just Vrms * Irms. It's the magnitude of the complex power, of which real power is just the real part. Power, S = P + jQ = V . I* = |V| |I| (cos(arg(V) - arg(I)) + j sin(arg(V) - arg(I))) Where |X| is the magnitude of X (X given in rms) and arg(X) is its phase.

[QUOTE=r0b0tsquid;47256131]I think you might have mistyped, apparent power is just Vrms * Irms. It's the magnitude of the complex power, of which real power is just the real part. Power, S = P + jQ = V . I* = |V| |I| (cos(arg(V) - arg(I)) + j sin(arg(V) - arg(I))) Where |X| is the magnitude of X (X given in rms) and arg(X) is its phase.[/QUOTE] You're right, I got ahead of myself.

Took me long enough to find the new thread... Speaking of radios, I coincidentally purchased a new radio a few weeks ago. [t]http://i.imgur.com/HP2mGInl.jpg[/t] These things are amazing for being so cheap. I really want to build my own VHF transceiver and from what I've been reading about on RF design and VHF communication, nothing should be that difficult. Anybody ever have a go at making their own transmitter/receiver? Sure I could just buy one, but where's the fun in that?

You'll need to possess a US General or Extra license to build (operate) a DIY transmitter on VHF. [URL=http://m.ebay.com/itm/191210888951]That being said[/URL]...

I'm having way too much fun with these TV guts. [IMG]http://i11.photobucket.com/albums/a166/ballsandy/IMG_8417.jpg[/IMG] [IMG]http://i11.photobucket.com/albums/a166/ballsandy/IMG_8421.jpg[/IMG] 105" screen on a 72" throw with mechanical focus and convergence issues. The tubes are designed for an optimal convergence distance of only 36" but nothing says that some nuts and bolts, and possibly some washers and springs can't make the projection angles variable and thus a MUCH wider convergence range. Too bad this whole thing is 480i.

I eagerly await seeing you use that to make a 108" projected picture of your face saying "WHO DARES ENTER MY REALM" when people walk into your house.

[QUOTE=Cakebatyr;47261314]I eagerly await seeing you use that to make a 108" projected picture of your face saying "WHO DARES ENTER MY REALM" when people walk into your house.[/QUOTE] "I. AM. OZ! THE ALL-POWERFUL! WHO-ARE-YOU?!"

[QUOTE=Cakebatyr;47261044]You'll need to possess a US General or Extra license to build (operate) a DIY transmitter on VHF.[/QUOTE] How much trouble could you get in for using one on a private channel that you own with a couple of your friends, though? I'm just interested because I'd love to make a little arduino-powered radio for my car.

Probably none, in the US I believe there is currently one "FCC Official Observer" per 1000 hams. But 144-148MHz is a small space. Its easier just to get a license.

I suppose that makes sense. My friends and I actually run in the 150mhz band, and I don't actually have a ham license, either, but we've been playing with radios for two years now with no issues. I may have to take a look at that chip you posted. With a decent amp it could be a pretty nice radio in the making.

[QUOTE=Cakebatyr;47263199]Probably none, in the US I believe there is currently one "FCC Official Observer" per 1000 hams. But 144-148MHz is a small space. Its easier just to get a license.[/QUOTE] Not only that but with General/Extra license you'll have access to a variety more of encoding protocols. I.e. if your arduino radio had a low speed comms you could save on space by using PSK31 encoding (only uses ~80Hz bandwidth). As for diy transceivers, I found it generally easier to build do with lower frequencies, especially in HF. As you get to a point were parasitic capacitance becomes harder to control. However, I recommend you check out [URL="http://www.electrical-workbench.co.uk/2014/06/colpitts-common-collector-oscillator.html"]Chryseus's site[/URL] for a good oscillator (As well as looking up Colpitts oscillators in general), [URL="http://www.talkingelectronics.com/te_interactive_index.html"]Talking Electronics[/URL] typically has a slew of good VHF/UHF circuits, check [URL="http://www.arrl.org/vhf-projects"]ARRL[/URL] (Especially this [URL="http://www.arrl.org/files/file/Technology/tis/info/pdf/9909033.pdf"]circuit[/URL]), & maybe [URL="http://www.discovercircuits.com/V/vhf.htm"]Discover Circuits[/URL]. If you're feeling adventurous, I'd also recommend looking up PLL controlled transceivers, very stable.

Unless you're running in frequencies currently allocated to others or otherwise jamming up the airwaves for other, run sans-license. It's like drones. They don't really care for the most part unless you're being stupid or being blatently obvious to everyone that you're broadcasting on regulated frequencies without a license.

I found this box in a drawer of project enclosures at my uni's electronics lab today. (It's pretty tiny, I think those are M3 screws) [IMG]http://i.imgur.com/6Io0i5I.jpg[/IMG] Been in that drawer for 62 years. [IMG]http://i.imgur.com/1a42Vy5.jpg[/IMG] I added my date and put it back into the drawer for the next wide-eyed engineering fresher to discover.

[QUOTE=Zero-Point;47262831]"I. AM. OZ! THE ALL-POWERFUL! WHO-ARE-YOU?!"[/QUOTE] [highlight]WHO DARES MAKE A MOCKERY OF THE ALMIGHTY PENTIUM?![/highlight] *pyrotechnics* *fwoosh* *pyrotechnics* [IMG]http://i11.photobucket.com/albums/a166/ballsandy/IMG_8441.png[/IMG] Alternately, put a camera facing up in a hole somewhere and in a building elsewhere if you look up you just see sky and the odd person looking down at you.

[QUOTE=pentium;47263560][highlight]WHO DARES MAKE A MOCKERY OF THE ALMIGHTY PENTIUM?![/highlight] *pyrotechnics* *fwoosh* *pyrotechnics* [url]http://i11.photobucket.com/albums/a166/ballsandy/IMG_8441.png[/url] Alternately, put a camera facing up in a hole somewhere and in a building elsewhere if you look up you just see sky and the odd person looking down at you.[/QUOTE] Needs more lasers and pyrotechnics and metal

[QUOTE=Cakebatyr;47261044] [URL=http://m.ebay.com/itm/191210888951]That being said[/URL]...[/QUOTE] Wow, this module really is an all-in-one job for a transciever. I think I might have to order one and see if I can make an ultra-compact radio to hide somewhere in my car.

There is a thread highlights section now in the op.

Hooray, my stepper motors and controllers for my DIY CNC plasma table have arrived!

Ugh, fucking fine. Here's content even though that faggot assmunch of a thick-rimmed hipster piece of Portland trash stole my work and drowned in nerd pussy and acne grease. (No, I do not like this guy or his efforts because there is none in comparison, even though he is being treated like a fucking king. He can go die in a flaming chamber full of chlorine for all I care.) The LS00 arrived and after running through a quick issue with ddrl46 I pulled out all the previous work and realized I can't mount the chip 90 degrees to the PCB like I intended because then the cover on the teletype machine wouldn't fit. Instead it was mounted on riser pins and hung over part of the serial port where the diode pack used to be. The three pin TTL line from the ProMini was replaced with an angled three pin header and tucked away under the new riser. [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_8468.jpg[/IMG] [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_8474.jpg[/IMG] It's done. There. The current loop to RS-232 adapter now has two serial inputs and it should work as expected. Now to complete the AC line switching and 5/12v power regulation assembly which will all end up being mounted on the stand. [IMG]http://i11.photobucket.com/albums/a166/ballsandy/Computer%20related/IMG_8478.jpg[/IMG]

We still love you though and that's all you need. Still, it seems like you're doing a much more hideaway and clean build and you take better photos anyway.

I can never get my wires that neat. How do you do that?

[QUOTE=Cakebatyr;47283422]I can never get my wires that neat. How do you do that?[/QUOTE] Use solid core wire, you can bend it and it stays in shape.

I do, I'm just bad at eyeballing/striping it.

-Snip, found it-

I recycle the header cables off motherboards. The cables are pre-praided. [QUOTE=papkee;47282625]Still, it seems like you're doing a much more hideaway and clean build and you take better photos anyway.[/QUOTE] I've been receiving a stupid amount of flak for this since this blew in due to my public responses. Someone pulled up my dox again, presumably because I said his idea was "too simple and incomplete" (that or because I openly stated that hipsters are trash). Hell, even here my comments aren't going over well but fuck you, this is facepunch. Everyone hates eachother here. Seriously. He had a loop adapter and two modems, one of which that stupid Livermore acoustic coupler everyone keeps fucking saying is the oldest existing modem. I'd dispute his ass any day of the week if I had the chance. Sure, the connecting the teletype to a computer using modems WAS a lot more interesting than just a direct connection (and why I assumed that nobody else would of bothered trying this) but it's still pretty simple. If I wanted that I would of been done this last year. Hell, it WAS done last year albeit over a lossy cellular connection and was even proving that automatic paper tape control was possible. [media]http://www.youtube.com/watch?v=rnR-h51wh6s[/media] Shit flew like a lead balloon until asshole shows up and hijacks the show. You guys have seen this progress from the start. You can see why I'm so frustrated. I get nothing out of this anymore. I can't even use this for portfolio/publicity material now that it's been done before. I get rewarded with fucking porn soundboards being piped over my phone at 2AM. Anyways, moving on.....

Remember when nerds did cool nerd stuff because it was fun for them and not because it made them a "better nerd" than other nerds? Pepperidge Farm remembers.

[QUOTE=Zero-Point;47286946]Remember when nerds did cool nerd stuff because it was fun for them and not because it made them a "better nerd" than other nerds? Pepperidge Farm remembers.[/QUOTE] It always made them better nerd.