Electrical Engineering V3

[LoneWolf_Recon]

[QUOTE=false prophet;51852671]Wow this is great stuff. I'll definitely save some money because I was looking at some cheaper stuff.[/QUOTE]

[sp]Don't know if sarcastic? :x [/sp]

The RTL-SDR are bad for radio telescopes namely due to their lack of sensitivity (I mean its a DVB dongle at its core, so its not really useful for too much except for terrestrial broadcasts).

That being said, people have created [URL="http://superkuh.com/rtlsdrinterferometer.html"]VBL interferometers using just RTL-SDRs alone, however that requires multiple dishes[/URL].

[Chryseus]

[img]http://i.imgur.com/KA3n6V0.png[/img]

I have to say KiCad has come a long way since I last tried it, I would definitely call it very usable now, in fact I'm probably going to switch entirely to it so I can do all my work on Linux, the only thing it lacks is nicely integrated simulation, but meh there are plenty of options for that.

[pentium]

I found something at work today~

[img]http://i11.photobucket.com/albums/a166/ballsandy/New%20Bucket/IMG_7128.jpg[/img]

[IMG]http://i11.photobucket.com/albums/a166/ballsandy/emoicons/Thunder.png[/IMG][IMG]http://i11.photobucket.com/albums/a166/ballsandy/emoicons/emot-science.gif[/IMG][IMG]http://i11.photobucket.com/albums/a166/ballsandy/emoicons/Thunder.png[/IMG]

[DrLuke]

[QUOTE=Chryseus;51856591][img]http://i.imgur.com/KA3n6V0.png[/img]

I have to say KiCad has come a long way since I last tried it, I would definitely call it very usable now, in fact I'm probably going to switch entirely to it so I can do all my work on Linux, the only thing it lacks is nicely integrated simulation, but meh there are plenty of options for that.[/QUOTE]

I never could get friendly with KiCad. While the layouter has some really powerful features, the rest of the Program is utter shit and a UX nightmare. I should try to get into Alitum or something, now that their student licenses are actually affordable.

Fun fact: Their germany sales headquarters is just down the street from my new office, and they offer free courses for people interested in buying!

[nikomo]

[QUOTE=Chryseus;51856591]the only thing it lacks is nicely integrated simulation, but meh there are plenty of options for that.[/QUOTE]

FYI, nightly has ngspice integration, but I wouldn't unfortunately call nightly usable in day-to-day usage.
Right now the best way to use KiCad day-to-day is 4.0.5 stable, but download this [URL]https://github.com/KiCad/kicad-library/[/URL] and replace the stock libraries files with the files from that.

The library that shipped with 4.0.5 has "Datasheet" and "Footprint" fields showing by default on schematic symbols, so you end up with something like this:
[IMG]http://i.imgur.com/70YlexQ.png[/IMG]

If you don't update the libraries, you have to hide those manually for every schematic symbol you use, where you use those fields.

[Chryseus]

[QUOTE=DrDevil;51858561]I never could get friendly with KiCad. While the layouter has some really powerful features, the rest of the Program is utter shit and a UX nightmare. I should try to get into Alitum or something, now that their student licenses are actually affordable.

Fun fact: Their germany sales headquarters is just down the street from my new office, and they offer free courses for people interested in buying![/QUOTE]

I found the UX to be pretty good in my opinion, if anything I prefer it over Altium purely for its simplicity, not once did I have to refer to the documentation or google anything, Altium is definitely powerful but there is so much stuff in it, getting lost is quite easy.

[QUOTE=nikomo;51858601]The library that shipped with 4.0.5 has "Datasheet" and "Footprint" fields showing by default on schematic symbols, so you end up with something like this:
[/QUOTE]

Yeah I noticed that, seems to be a problem with 4.0.4 as well.

[ben1066]

[QUOTE=LoneWolf_Recon;51850985]I haven't built anything larger than a repurposed DISH network antenna (Reused as a WiFi Cantenna). However if you're serious about this, I'd recommend saving up atleast $300 to $500 on electronics alone, those $20 RTL-SDRs from Amazon won't cut it for anything too useful IMO.

I'd recommend looking for an SDR with the following specs:
-Atleast 10-bits in ADC resolution (Really helps with SNR)
-Something that can receive in the 70cm (~440MHz) to S-Band (~2.4GHz), especially if you want to do Hydrogen-Line measurements/monitoring.
-Minimum bandwidth of 10MHz (20MHz preferable)
-Bonus if you can mount it in an metal case to cut down on EMI/RFI.

[URL="http://www.rtl-sdr.com/roundup-software-defined-radios/"]Here's a good list[/URL], I'd recommend the SDRPlay RSP1 or 2, MyriadRF or the BladeRF as all are proven and have GNURadio support.

In terms of LNA, go for one with a low noise figure (<2dB preferable) and low VSWR (<1.4 preferable) and then choose whatever frequency range you wanna listen too.

Good sources for LNAs within budget are [URL="http://rfbayinc.com/subcategory_product.php?cPath=83"]RFBay[/URL], [URL="http://lna4all.blogspot.com.au/"]LNA-For-All[/URL] is great (They target SDR specifically) and then various ebay sellers ([URL="http://www.ebay.com/itm/Ultra-Low-Noise-Amplifier-10-6000-MHz-RF-LNA-40-dB-Gain-0-8-dB-Noise-Figure-/282319840770"]this is a good one[/URL]).[/QUOTE]

I got one of the LimeSDR early bird units, for 200$ certainly a better deal than I think 300$ retail, but might be worth adding to the list.

[F.X Clampazzo]

Radio telescope sounds like a badass project. My only personal project recently is later today I'm swapping the hazard relay from one broken turn/hazard relay set into another broken one to get one working relay set hopefully. The logic goes that the turn relay goes bad but the hazard one should be perfectly fine since it isn't used near as much. Fucking one in my car started clicking and it's bugging the crap out of me so $10 to maybe fix a $60 part is maybe a good deal.

I tried cleaning the fuck out of the relay and it helped a bit but magnetic relays aren't something I actually know much about and beyond a good cleaning and messing with changing the gap a bit I can't seem to do any lasting fix to my current one. I assume maybe they just over time got magnetically charged or some shit and the resistance becomes so low that it just can't resist clacking about. You'd think I'd have learned about these in class by now but nah.

[LoneWolf_Recon]

[QUOTE=ben1066;51860174]I got one of the LimeSDR early bird units, for 200$ certainly a better deal than I think 300$ retail, but might be worth adding to the list.[/QUOTE]

Does it support GNURadio? I was hesitant in including it because early access.

[pentium]

[QUOTE=pentium;51856633]I found something at work today~

[t]http://i11.photobucket.com/albums/a166/ballsandy/New%20Bucket/IMG_7128.jpg[/t]

[IMG]http://i11.photobucket.com/albums/a166/ballsandy/emoicons/Thunder.png[/IMG][IMG]http://i11.photobucket.com/albums/a166/ballsandy/emoicons/emot-science.gif[/IMG][IMG]http://i11.photobucket.com/albums/a166/ballsandy/emoicons/Thunder.png[/IMG][/QUOTE]

Now with more being wired up.

[IMG]http://i11.photobucket.com/albums/a166/ballsandy/New%20Bucket/IMG_7150.jpg[/IMG]

[Lenny.]

What is it what does it do

[LoneWolf_Recon]

[QUOTE=LennyPenny;51863473]What is it what does it do[/QUOTE]

Make miracles.

[sp]With 7.5kV 30mA arcs[/sp]

[F.X Clampazzo]

[QUOTE=LennyPenny;51863473]What is it what does it do[/QUOTE]

The only way to know for sure, as with anything that looks sufficiently industrial, is to lick it.

There's a reason Engineers are always in demand after all, no better testing methods exist.

[Zero-Point]

I'm glad you guys know what's going on, because nothing's loaded for me. :v:

[ben1066]

[QUOTE=LoneWolf_Recon;51860952]Does it support GNURadio? I was hesitant in including it because early access.[/QUOTE]

Yeah, they've had GNURadio support for a while now I think [url]https://myriadrf.org/blog/limesdr-application-ecosystem/[/url] . I haven't really tried it out but it can definitely be made to work, someone did DVB-S2 with it [url]https://myriadrf.org/blog/digital-video-transmission-using-limesdr-gnu-radio/[/url] .

An aside, they currently have an issue with HF being attenuated, but it seems removing a single component on the board fixes the issue, they addressed it at [url]https://www.crowdsupply.com/lime-micro/limesdr/updates/optimising-performance-on-hf[/url] and it won't affect radio astronomy anyway.

[LoneWolf_Recon]

After the headache of replacing dead LEDs and drivers from last week, we finally finished our 2.5kW LED panel. Its bright af (the ceiling lights were still on):

[img_thumb]https://scontent.fbna1-1.fna.fbcdn.net/v/t1.0-9/16508612_10211953250536305_5260635307026020186_n.jpg?oh=5be21996f556758aa46f2f4a9fd07ed0&oe=592B57D9[/img_thumb] [URL="http://sev.h-cdn.co/assets/16/17/980x490/landscape-1461785169-edna-mode.jpg"]???[/URL]

And it makes a really cool shutdown effect when its turned down to low power.

[vid]https://my.mixtape.moe/wcvvix.mp4[/vid]

As an aside, anyone have recommendations for a solid mixed signal digital scope for under $500? Preferably 100MHz, but 50MHz will do.

[Zero-Point]

[QUOTE=LoneWolf_Recon;51873937]After the headache of replacing dead LEDs and drivers from last week, we finally finished our 2.5kW LED panel. Its bright af (the ceiling lights were still on):

[img_thumb]https://scontent.fbna1-1.fna.fbcdn.net/v/t1.0-9/16508612_10211953250536305_5260635307026020186_n.jpg?oh=5be21996f556758aa46f2f4a9fd07ed0&oe=592B57D9[/img_thumb] [URL="http://sev.h-cdn.co/assets/16/17/980x490/landscape-1461785169-edna-mode.jpg"]???[/URL]

And it makes a really cool shutdown effect when its turned down to low power.

[vid]https://my.mixtape.moe/wcvvix.mp4[/vid]

As an aside, anyone have recommendations for a solid mixed signal digital scope for under $500? Preferably 100MHz, but 50MHz will do.[/QUOTE]

-snip lol you said mixed signal I can't fucking read-

Even Rigol's cheapest offering is $835, I'm afraid.
But a quick search yielded this, though I'm not sure about the brand's reputation.
[url]https://www.amazon.com/Hantek-MSO5202D-200MHz-Oscilloscope-Analyzer/dp/B00HYYCY5O/ref=pd_sbs_328_t_1?_encoding=UTF8&psc=1&refRID=5ZRE6Y9XQDNTAPY0N26M[/url]

[LoneWolf_Recon]

[QUOTE=Zero-Point;51874158]-snip lol you said mixed signal I can't fucking read-

Even Rigol's cheapest offering is $835, I'm afraid.
But a quick search yielded this, though I'm not sure about the brand's reputation.
[url]https://www.amazon.com/Hantek-MSO5202D-200MHz-Oscilloscope-Analyzer/dp/B00HYYCY5O/ref=pd_sbs_328_t_1?_encoding=UTF8&psc=1&refRID=5ZRE6Y9XQDNTAPY0N26M[/url][/QUOTE]

Oh, any digital scope with atleast 50MHz will do. I didn't know Mixed Signal jacked up the price.

[MadsAG]

[QUOTE=LoneWolf_Recon;51874303]Oh, any digital scope with atleast 50MHz will do. I didn't know Mixed Signal jacked up the price.[/QUOTE]

Then Rigol DS1054Z, there's not really any contender.
When you hack the 100 MHz and other features, your 400$ scope becomes a 1200$ one.

[Zero-Point]

[QUOTE=LoneWolf_Recon;51874303]Oh, any digital scope with atleast 50MHz will do. I didn't know Mixed Signal jacked up the price.[/QUOTE]

There's a PC-based scope called the PicoScope. Without MSO, the 50MHz 2-channel version is ~$472. MSO bumps that up to ~$734. :v:

[Ddrl46]

[QUOTE=LoneWolf_Recon;51874303]Oh, any digital scope with atleast 50MHz will do. I didn't know Mixed Signal jacked up the price.[/QUOTE]

I'd wait for the new Keysight 1000X series that is due to be announced on the 1st of March, the Rigol is nice and all for the price (I have a DS1054Z myself) but the user interface and usability isn't exactly ideal.

[pentium]

[QUOTE=LoneWolf_Recon;51873937]After the headache of replacing dead LEDs and drivers from last week, we finally finished our 2.5kW LED panel. Its bright af (the ceiling lights were still on):

[img_thumb]https://scontent.fbna1-1.fna.fbcdn.net/v/t1.0-9/16508612_10211953250536305_5260635307026020186_n.jpg?oh=5be21996f556758aa46f2f4a9fd07ed0&oe=592B57D9[/img_thumb] [URL="http://sev.h-cdn.co/assets/16/17/980x490/landscape-1461785169-edna-mode.jpg"]???[/URL]

And it makes a really cool shutdown effect when its turned down to low power.
[/QUOTE]

What are you using for a power supply? I've been trying to make a bunch of high intensity LED backlight assemblies from some junked monitors work but it seems as they warm up their current draw skyrockets and drivers kick out.

[IMG]http://i11.photobucket.com/albums/a166/ballsandy/New%20Bucket/IMG_7018.jpg[/IMG]

My attempts with (admittedly cheap) 250W power supplies has been unsuccessful.

[LoneWolf_Recon]

[QUOTE=pentium;51881662]What are you using for a power supply? I've been trying to make a bunch of high intensity LED backlight assemblies from some junked monitors work but it seems as they warm up their current draw skyrockets and drivers kick out.

[IMG_THUMB]http://i11.photobucket.com/albums/a166/ballsandy/New Bucket/IMG_7018.jpg[/IMG_THUMB]

My attempts with (admittedly cheap) 250W power supplies has been unsuccessful.[/QUOTE]

We have a [URL="https://www.digikey.com/product-detail/en/xp-power/HDS3000PS60/1470-2686-ND/5023628"]dedicated 3kW XP Power 60V Supply[/URL], it helps to have one with a slow ramp up because this fucker can and will weld shit together. Of course its $1200.

[img_thumb]https://media.digikey.com/Photos/XP%20Power/HDS3000-SERIES.jpg[/img_thumb]

[Goz3rr]

I need to control couple of dozen solenoids (not sure on what kind yet, probably 12V 2A or 5V 1A), would a bunch of PCBs like this chained together work or am I doing something stupid?

Only a few of them will be on at once but they might be held for a few seconds at a time. I've checked the max current the 74HC595 can provide (70mA total, 25mA per pin) which shouldn't be an issue with the TIP120 having a DC Current Gain factor of 1000

[img]https://i.imgur.com/1uKpuPX.png[/img]

[LoneWolf_Recon]

Yup, that should work as long as you disable all the outputs on your 595 chain until you've shifted out your data and/or reset your states it should be fine.

Recommendation to put atleast a 270 Ohm resistor for each of the base resistors because higher current draw means lower output voltage from the 595 thus hindering the base drive capability of the TIP120.

Also put some decoupling caps (100nF) + a fairly large cap (~100uF) with each of your 595.

[Goz3rr]

[QUOTE=LoneWolf_Recon;51884624]+ a fairly large cap (~100uF) with each of your 595.[/QUOTE]

Where would this go, the same place as the decoupling caps?

[LoneWolf_Recon]

[QUOTE=Goz3rr;51884981]Where would this go, the same place as the decoupling caps?[/QUOTE]

Yeah, depending upon how much you change the states, each 595 will be switching relatively a large amount of current.

[Van-man]

I'd ditch those TIP120's for some N-channel mosfets if you haven't purchased parts yet.

[Goz3rr]

[QUOTE=Van-man;51886371]I'd ditch those TIP120's for some N-channel mosfets if you haven't purchased parts yet.[/QUOTE]

Do you have any suggestions for logic level MOSFETs that can take at least 12V 2A?

[LoneWolf_Recon]

[QUOTE=Goz3rr;51886604]Do you have any suggestions for logic level MOSFETs that can take at least 12V 2A?[/QUOTE]

I agree, here you go a [URL="http://www.mouser.com/ProductDetail/Nexperia/PSMN022-30PL127/?qs=sGAEpiMZZMshyDBzk1%2fWiy8mkjihaa%2bLT7ikOfKaAiM%3d"]PSMN022-30PL[/URL] its slightly cheaper than the TIP120 too. And you probably wont need to add heatsinks to them.

With this you can probably ditch the 100uF cap I mentioned earlier and stick with just the decoupling cap. However I recommend keeping the base resistors in the off chance that the gate ruptures and current flows from your 12V line to your 5V logic.