Learning electronics: Release the Magic Blue Smoke

The Something Awful Forums > Discussion > Hobbies, Crafts, & Houses > Learning electronics: Release the Magic Blue Smoke

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

The issue is, if 10 electrons fart and your Arduino / microcontroller reboots or does strange things while hooked up to your lighting or outdoor sprinkler, nothing much happens. If the same happens while hooked up to a gas system, you might asphyxiate or blow up your house/kids/cat.

# ¿ Sep 18, 2017 16:44

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# ¿ May 8, 2024 15:11

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

mobby_6kl posted:

First ever magic smoke, from a chinese power supply

Half of the mosfet is gone as well as whatever was here:

I don't really see what I could've messed up, it's only hooked up to an LED strip, it blew the moment I turned the power on. Are the resistors' leads supposed touch that way?

As a dude looking at electronics for a living, that thing is a nightmare from the dark past of electronics.
That thing holds the same attraction as the really bad gooncave pictures - its all awful and you keep seeing the next worst thing on there.
The MOSFET looks to have had a short circuit, leading to bond wire going kablooey and sending bits of epoxy everywhere. Every single component is installed off axis and with total disregard for neatness and isolation distance or even sanity. Looking at it, are the two blue-ish resistors touching leads? It might be an artifact of the angle you took the picture, but that could short out the MOSFET and cause the fuse next to the bridge rectifier to belatedly realize something is wrong and give up on life.

Please promise you'll never use mains voltage around anything from that supplier again, its the worst Made In China burn-your-house-down poo poo.

# ¿ Nov 27, 2017 18:44

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

Fristly, the arduino thread is this: https://forums.somethingawful.com/showthread.php?threadid=3505424

There is a great deal of overlap between people posting in these threads, but atleast software questions is more suited for that thread.

To give a walkthrough of how Id approach one of your ideas: Tuning the radio antenna

First, an idea or a purpose for your build - you're well set there.

Two, breaking the idea down into cause and effect logical blocks. Firstly, you will have some type of sensor reacting to the rotation of the antenna. Secondly, you'll have an output responding to the first sensor, in your case perhaps a light turns on and a speaker plays a sound. Between those you'll have some wires and some glue logic

Thirdly, brainstorm hardware with price and purpose that fits your needs. For the sensor, Id suggest a Hall effect sensor and a little magnet glued to a outrigger on the antenna, somewhere the audience cant see. When the antenna turns into the correct position, the magnet moves near the hall effect sensor, which is read by the controller (perhaps an Arduino). For the lights/sound, a LED and a speaker with perhaps a driver depending on desired volume.

Fourth, find suitable components - ask here, buy from digikey or whatever or a local hackerspace.

Fifth, breadboard prototype. A breadboard is this. A quick and dirty way to test a (low-power) circuit. You can plug the components in and test hardware/software.

Then it gets a little fuzzy. You might transfer to a Veroboard / stripboard (soldering, yay!) or for more complicated stuff, get a PCB made - either DYI (chemicals) or China (takes a little knowledge).

As rawrr mentions, kits are an option. Some starter kits are pretty solidly made with good documentation and explanation - others are a pile of components and a PCB, good luck!
The official Arduino starter kit is expensive (100$) but comes with a book, some components and directions to get started. If you can find it cheaper or a knockoff, its a place to start.

# ¿ Dec 15, 2017 20:40

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

chitoryu12 posted:

Well, I have specific objectives in mind but I don't plan on actually constructing them for about a year. I'd like for my skills and knowledge in electronics to be more than just learning how to do each individual thing I want to do, so I'd like to have a breadboard for my first hands-on experimenting and some useless little projects to solder together first like simple lights or motors. I figured a kit would be a good way to get the really basic equipment and practice cheaply before buying things meant for specific projects and accidentally ruining them.

Ah, the joys of China and electronics. Dinky electronics are incredibly cheap from China - a few dollars shipped. The guideline I've heard when ordering is to order 3 of something you need 1 of. One that wont work on arrival, one to fumble and blow up, one to actually do the thing.

# ¿ Dec 15, 2017 20:43

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

ate all the Oreos posted:

Wait are you supposed to use that teeny tiny amount of solder paste even for those huge pads? I've been doing it wrong

The way commercial SMD systems do this is with a thin sheet of aluminum with lasercut holes for each solder pad. A layer of paste is passed over the sheet so paste is deposited onto all pads in a single pass. The sheet is removed and pick and place happens afterwards.
I saw a lecture on doing THT components with SMD paste systems, skipping the wave soldering process altogether. You calculate the volume of the barrel in the THT hole, and place an eqiuvalent amount of paste in a "window" (like the windows logo) with the center cross on the THT hole. The paste touches the leg of the component and the solderpad around the hole, and surface tension pulls in into the barrel of the hole at reflow temperature.

# ¿ Feb 16, 2018 10:22

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

Acid Reflux posted:

I'm now the proud owner (well, the company is) of a Pace PRC2000.

I haven't done any 2M work in 11 years now...not that I've really forgotten the techniques, but I'm quite obviously sorely out of practice. I don't suppose anyone has a PDF of the military standards manual for such things?

I havn't done work according to the MIL STD specs, a round of google points to the following:
MIL-STD-2110, MILITARY STANDARD: RESTORATION, OVERHAUL, AND REPAIR OF ELECTRONIC EQUIPMENT - which is positively ancient at dec 1979
MIL-STD-2111, MILITARY STANDARD: TECHNICAL REPAIR STANDARDS - ELECTRONIC (2Z/4G/7Z/7G REPAIRABLES), PREPARATION OF - same ancient date.
(found http://everyspec.com/MIL-STD/MIL-STD-2000-2999/ )

Also that PRC2000 looks pornographic.

# ¿ Mar 1, 2018 13:03

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

I�m using a EA-PS 8080-170 at work, and they�re great workhorses, their loads are solid as well.

# ¿ Oct 10, 2018 15:42

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

Shame Boy posted:

Yeah, all plants have to sync up to the grid so they're not at risk of interference cancelling each other out (and until they sync up they dump their power output into what is basically a massive building-sized resistor which is real cool imo) but the grid as a whole could slowly drift if everyone's just using the grid itself as the reference they're sync'd to. I think America's grid is still very very accurate but I know Europe's grid has been having weird issues with frequency drift lately that may or may not be Russia intentionally loving with it...

https://www.theguardian.com/world/2018/mar/08/european-clocks-lose-six-minutes-dispute-power-electricity-grid
Amusingly, it was because of the Kosovo / Serbia "history". All of EU would much rather have slow clocks than try to intervene there.

# ¿ Nov 21, 2018 19:18

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

Mr. Bubbles posted:

Sorry, should have mentioned not water. It's a fuel, so definitely flammable if that changes my options.

Go buy something here:

https://www.sick.com/us/en/fluid-sensors/level-sensors/c/g98155

Find a sensor that suits your needed depth and desired output with an ATEX approval. If a real sensor is out of your budget, walk away.
Don�t DIY something in a fuel vapor atmosphere.

# ¿ Nov 13, 2019 22:06

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

FISHMANPET posted:

Ok I've got these two kinds of switches/buttons:
Trigger Switch
Push Button

They've both got the the little tabs where wire connects. Can I use something like a "female disconnect" to actually connect wires to that? Amazon has suggested this, would that be the right sort of thing (adjusting for size, the trigger leads are different sized than the button leads), and do I need a special kind of crimper for that? I've got this wire tool which works for stripping wire and can do some kind of crimping.

Yes, those are the correct connectors and a matching tool. Note how the plastic around the female connectors are red, and there's a red marking near the tip of your crimper? Those match. If you get female connectors with larger wires, they will be blue/yellow plastic and be suited for the yellow/blue marking on your crimper.

# ¿ Jan 22, 2020 18:26

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

Wallrod posted:

Any tips on soldering to that weird gold-coloured center post on this 3.5mm, 3-pole jack? It's hollow below the cut, but not by much.

I've only done some slightly messy but functional through-hole circuit board soldering before, but i'm modding my headphones to have a removable cable. I thought i'd adapt my old fixed cable to male-male for the experience while i'm at it, but i've received this instead of the more accommodating looking version on the product listing. I'm tempted just to send it back and order from somewhere else, though that feels a bit fussy, and it's another few days of waiting. It's hard to find videos or advice for these kinds of post, because i've got no idea what to even search for, and they seem to be uncommon.

If you're looking for tutorials or videos, that type of terminal is called a "solder cup". If you want to see the professional standards for those things, heres NASA's quality guidelines:
https://workmanship.nasa.gov/lib/insp/2%20books/links/sections/614%20Solder%20Cups.html

# ¿ Jun 9, 2020 10:57

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

insta posted:

I'm at the total napkin-scratching phase, but what's the cheapest way to outfit my house with sensors to record ambient data, because I like big CSV files?

I'd want humidity, temperature, barometric pressure. I'd want to gather this from about 15 spots in my house. I currently have more time than money thanks to a COVID-19 furlough, and I've designed PCBs before.

My initial thought was Attiny85s, those 433MHz modules, and Chinese sensors. Report all that data to a Raspberry Pi for cataloging. I'm aware of ESP32s, but will Attiny85s+433mhz end up cheaper per unit (or more reliable/longer range)?

Is there some existing off-the-shelf thing for $9 that does what I want?

This is very much not 9$, but if you want some rugged sensors you could put on a single CAN bus, the CAT-HSA0004 from TE would be a fun project. Its 170$ a pop, and meant for instrumentation in automotive, truck or fuel cell systems.

# ¿ Jul 19, 2020 19:34

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# ¿ May 8, 2024 15:11

Maimgara: May 2, 2007; Chlorine for the Gene-pool.

ryanrs posted:

Grounding Chat

I've been looking at this Click Plus PLC wrt grounding. Mostly because high res pics and specs were easy to find.

Observations:

1. Exposed metal on antenna and USB jack. These must be attached to chassis ground, per UL 508.

2. The negative supply rail is isolated from the chassis ground, 1000VAC dielectric test.

To do this, I imagine they use a 24V input, isolated dc-dc switcher. Prob something like this.

Adding an isolated supply to my board would be straight forward, but I'm not going to do it. It seems extremely unnecessary when I'm bonding the negative rail to safety ground anyway. I think I understand why industry does it that way, but for a one-off personal project, it seems like an OK corner to cut. Just don't integrate the poo poo Alarm into a positive ground installation (looking at you, telecom).

Most PLCs are signifiantly less fancy than using isolated switchers - the front power suipply connector has 3 pins - positive, negative and PE. The chassis and metal parts are grounded via the PE connection, which the panel builder is responsible for providing a suitable ground to. In nearly all electrical cabinets, the 24V negative is grounded, so on the PLC negative and PE is effectively the same potential. For the dielectric test, the positive and negative are tired together and tested with reference to ground.

# ¿ Mar 29, 2024 20:14

The Something Awful Forums > Discussion > Hobbies, Crafts, & Houses > Learning electronics: Release the Magic Blue Smoke