Electrical Engineering V2 - Developers

[QUOTE=LoneWolf_Recon;41498746]Another recommendation is to put a reverse diode and a small (~0.1uF) cap across the relay. Unless you are using a sort of premade relay shield. I would recommend a mosfet (Most of the IRF series are great) instead due to the isolated gate, but a 2n2222 should work (Assuming the relay uses less than 800mA)[/QUOTE] I'm using some dudes plans and the parts he recommends, I'm JW if I wired it right, here's the whole thing [url]http://i.imgur.com/4HzhwYB.jpg[/url] AFAIK it's correct, I'm just cautious as a beginner since the pi doesn't have any real protection if I screwed something up [editline]17th July 2013[/editline] and what's the best way to connect my male wires to other male wires? surely there are couplers of some kind, what should I be searching for?

dude clearly has no idea what coils can do to your switching circuitry

Anyone have GOOD guides on how to make your own UHF/VHF scanner antennas and base station CB Antennas? All the ham sites seem to be so senile that they either make you assume a bunch of shit that the reader probably does not know or go for straight fucking overkill. [img]http://www.lightningantennas.com/Quads/wp-content/uploads/2011/03/L8chica.jpg[/img]

[QUOTE=pentium;41499868]Anyone have GOOD guides on how to make your own UHF/VHF scanner antennas and base station CB Antennas? All the ham sites seem to be so senile that they either make you assume a bunch of shit that the reader probably does not know or go for straight fucking overkill. [url]http://www.lightningantennas.com/Quads/wp-content/uploads/2011/03/L8chica.jpg[/url][/QUOTE] Building antennas always contains 40% black magic, that's why there aren't any "GOOD" guides unless you want to study wave physics and all that really fun stuff

I want to study wave physics

[QUOTE=DrDevil;41499974]Building antennas always contains 40% black magic, that's why there aren't any "GOOD" guides unless you want to study wave physics and all that really fun stuff[/QUOTE] Well even just how to make homebuilt versions of the classics. [url]http://www.ebay.com.au/itm/NEW-A99-HOME-BASE-STATION-CB-ANTENNA-w-GROUND-PLANE-MARINE-27MHz-A-99-AERIAL-/190787853457[/url] I mean, it's a 17.5' rod. Surely someone has made their own version of this using parts from The Home Depot.

[QUOTE=pentium;41500190]Well even just how to make homebuilt versions of the classics. [url]http://www.ebay.com.au/itm/NEW-A99-HOME-BASE-STATION-CB-ANTENNA-w-GROUND-PLANE-MARINE-27MHz-A-99-AERIAL-/190787853457[/url] I mean, it's a 17.5' rod. Surely someone has made their own version of this using parts from The Home Depot.[/QUOTE] Try an amateur radio group in your vicinity, they can surely help you out and point you to the right direction. Ask them for an "antennas for dummies" guide, and please post it for me aswell

[QUOTE=pentium;41499868]Anyone have GOOD guides on how to make your own UHF/VHF scanner antennas and base station CB Antennas?[/QUOTE] [url]http://www.mediafire.com/?ezbujkt80tjfrur[/url] Here you go.

[QUOTE=Chryseus;41504980][url]http://www.mediafire.com/?ezbujkt80tjfrur[/url] Here you go.[/QUOTE] Now THAT is black fucking magic. Why is the entire book written in D'ni? [IMG]http://i11.photobucket.com/albums/a166/ballsandy/untitled-5.png[/IMG]

Get Foxit reader, it displays it perfectly fine

A customer at the supermarket I work in (just filling the shelves and stuff as I can't do much else due to age) came along and told me that this lamp was lying in one of the fridges, and I took it with me as it seems to be in good condition [t]https://dl.dropboxusercontent.com/u/43645231/photos/electro/2013-07-19 17.48.55.jpg[/t] [t]https://dl.dropboxusercontent.com/u/43645231/photos/electro/2013-07-19 17.50.49.jpg[/t] I want to mess around with it but not destroy it, so I'd like to know what you guys think it'd need as a power source (I assume a battery but maybe it's some low-energy cost lamp or whatever? I really don't know :v:), there isn't any code or name on it either.

[QUOTE=scratch (nl);41520763]A customer at the supermarket I work in (just filling the shelves and stuff as I can't do much else due to age) came along and told me that this lamp was lying in one of the fridges, and I took it with me as it seems to be in good condition [t]https://dl.dropboxusercontent.com/u/43645231/photos/electro/2013-07-19 17.48.55.jpg[/t] [t]https://dl.dropboxusercontent.com/u/43645231/photos/electro/2013-07-19 17.50.49.jpg[/t] I want to mess around with it but not destroy it, so I'd like to know what you guys think it'd need as a power source (I assume a battery but maybe it's some low-energy cost lamp or whatever? I really don't know :v:), there isn't any code or name on it either.[/QUOTE] That looks like a starter for some fluorescent bulb. [img]http://www.extralight.info/extralicht/TL-starter.jpg[/img]

I'm putting a usb cable outside, and I assume it's not meant for the outdoors. Do they sell like sun protecting heat shrink tubing or something?

[QUOTE=Shadaez;41521726]I'm putting a usb cable outside, and I assume it's not meant for the outdoors. Do they sell like sun protecting heat shrink tubing or something?[/QUOTE] It will be fine as long as you don't get water in it. Of course safer to run it below ground in a PVC tube.

[QUOTE=Chryseus;41521763]It will be fine as long as you don't get water in it. Of course safer to run it below ground in a PVC tube.[/QUOTE] Plastics can get brittle from UV damage, I don't want that happening. It's just a short run and I'd like to protect it, I think I'll just wrap it in some electrical tape though, it's really only a few inches and I'm not even sure a small enough heat shrink tube would fit over the usb port

[QUOTE=ddrl46;41520934]That looks like a starter for some fluorescent bulb. [IMG]http://www.extralight.info/extralicht/TL-starter.jpg[/IMG][/QUOTE] but what does it do? I mean, what could I use it for and what should I look out for? [editline]19th July 2013[/editline] I saw a video of it and it just flickers a bit, but it looks nice. [editline]19th July 2013[/editline] it sure as hell got used a lot though as the entire tube is supposed to be clear, whilst mine is almost completely covered in something.

[QUOTE=scratch (nl);41522032]but what does it do? I mean, what could I use it for and what should I look out for? [editline]19th July 2013[/editline] I saw a video of it and it just flickers a bit, but it looks nice. [editline]19th July 2013[/editline] it sure as hell got used a lot though as the entire tube is supposed to be clear, whilst mine is almost completely covered in something.[/QUOTE] They are sometimes used to get these lights on: [IMG]http://www.led-verlichting.org/images/CAT_LED_TL_LAMP.jpg[/IMG] I'm saying sometimes because there's multiple ways to get a fluorescent light going. the starter you got has a tube filled with neon or mercury/quicksilver (don't know the correct noun, Google translate gave me those. Nederlands is kwik) and 2 contacts. When you apply the right voltage (prob 220-240 in your case), the gas ignites and heats the contacts up (that should be the light you're seeing) making the 2 contacts touch each-other which create a sort of short circuit. This gives the lamp the amount of current it needs to ignite it's gas, once the lamp is on the voltage is reduced over the starter so that the gas can't ignite anymore. Here's a basic schematic: [IMG]http://www.green-fox.nl/techinfo/images/TLCircuit.png[/IMG] The (| |) under the lamp is a starter. I don't know if there's any other fun uses for them though.

Replaced some capacitors on the CCFL-inverter board of an Acer monitor. [url=http://i.imgur.com/ueUQBH9.jpg][img]http://i.imgur.com/ueUQBH9l.jpg[/img][/url] I don't get why they use cheap-noname brand capacitors on the inverter and use high quality nippon-chemicon capacitors on the rest of the boards.

[QUOTE=ddrl46;41529733]Replaced some capacitors on the CCFL-inverter board of an Acer monitor. [url]http://i.imgur.com/ueUQBH9.jpg[/url] I don't get why they use cheap-noname brand capacitors on the inverter and use high quality nippon-chemicon capacitors on the rest of the boards.[/QUOTE] Because it's a predictable point of failure, forcing the common customer to buy a new monitor after x years and/or because the power supplies are made by a different engineering company (aka they just buy the design).

[QUOTE=ddrl46;41529733]Replaced some capacitors on the CCFL-inverter board of an Acer monitor. [url=http://i.imgur.com/ueUQBH9.jpg][img]http://i.imgur.com/ueUQBH9l.jpg[/img][/url] I don't get why they use cheap-noname brand capacitors on the inverter and use high quality nippon-chemicon capacitors on the rest of the boards.[/QUOTE] I had a friend have his monitor fuck up, because they put the power control board on the top where all the heat is and, well, BGAs. Thankfully he talked to me about it and I said "Just put it in the oven at 350 for about 10-15 minutes" and he says it works fine once again. I think he also somehow relocated the board so it's not exposed to as much heat.

[QUOTE=Zero-Point;41531305]I had a friend have his monitor fuck up, because they put the power control board on the top where all the heat is and, well, BGAs. Thankfully he talked to me about it and I said "Just put it in the oven at 350 for about 10-15 minutes" and he says it works fine once again. I think he also somehow relocated the board so it's not exposed to as much heat.[/QUOTE] I love how just stuffing electronics into the oven sometimes actually helps.

[QUOTE=Zero-Point;41531305]I had a friend have his monitor fuck up, because they put the power control board on the top where all the heat is and, well, BGAs. Thankfully he talked to me about it and I said "Just put it in the oven at 350 for about 10-15 minutes" and he says it works fine once again. I think he also somehow relocated the board so it's not exposed to as much heat.[/QUOTE] 99.9% procedure used for all Xbox RRODs.

[QUOTE=scratch (nl);41533058]I love how just stuffing electronics into the oven sometimes actually helps.[/QUOTE] I've gotta do that to my GPU I think, thing likes to crash in the dumbest moments (though I may have recently fixed that, we'll see). At any rate I've gotta fix my mom's old laptop using reflow techniques because the GPU is bork'd. Got the stuff to make a cheapy Radioshack hot-air iron, just been lazy about it.

[img]http://u.cubeupload.com/Chryseus/6PuQ0Q.png[/img] Progress on my sweep generator.

how do you guys mount PCBs on stuff. I need to put my pi, a relay board, and some other stuff in an enclosure and I can't figure out how. Preferably on Amazon or locally at a Lowes/Home Depot/Radio Shack or something.

[QUOTE=Shadaez;41545074]how do you guys mount PCBs on stuff. I need to put my pi, a relay board, and some other stuff in an enclosure and I can't figure out how. Preferably on Amazon or locally at a Lowes/Home Depot/Radio Shack or something.[/QUOTE] Screws and / or standoffs. Usually it's better and cheaper (particularly with larger things) to make your own enclosure, you can make them quite easily out of wood, brass sheet, copper sheet or anything else you desire.

I bought the smallest bolts and nuts I could find and they're just slightly too big. They might have had smaller ones, but I was just going to run the bolt through wood and use the nuts to hold it in place. Do they have bolts small enough?

[QUOTE=Shadaez;41545338]I bought the smallest bolts and nuts I could find and they're just slightly too big. They might have had smaller ones, but I was just going to run the bolt through wood and use the nuts to hold it in place. Do they have bolts small enough?[/QUOTE] If there is room on the PCB you could drill the mounting holes out a bit more, however you should be able to get something to fit, if you're not sure measure the hole and I will find you something suitable.

[QUOTE=Shadaez;41545338]I bought the smallest bolts and nuts I could find and they're just slightly too big. They might have had smaller ones, but I was just going to run the bolt through wood and use the nuts to hold it in place. Do they have bolts small enough?[/QUOTE] The mounting holes on the Raspberry Pi are M2.5, anywhere between M2 - M3 is quite common in electronics.

I think what I'll do is use these bolts/nuts to just hold the stuff up from the sides, if that makes sense. [editline]21st July 2013[/editline] The PI isn't really an issue, it's this relay board. I have a case for the pi with mounts.