Questions tagged [diy]

Do It Yourself. Build, modify, repair something without the aid of trained professionals.

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9
votes
3answers
33k views

Is there way to construct an 18650 battery pack with built-in balance charging? Or is balancing not very necessary?

This is my first post here. Err, I'm a DIY enthusiast especially in electronics. I'm actually building a portable Playstation 2 Slim with an IPS display, so that it would look like a Wii U controller....
9
votes
1answer
1k views

Soldering BGA components DIY

If I understood correctly, current BGA components contain solder balls under the package. Do I still need additional solder paste to put on the board, or the amount of solder on the component contacts ...
6
votes
6answers
3k views

Techniques for building 'Bed of Nails' testing board

When testing a complete circuit board a 'Bed of Nails' can significantly reduce time and errors. What are some techniques for making a DIY Bed of Nails? ...
5
votes
4answers
3k views

How to get 20 V from a USB-C charger?

I want to power my DIY stuff with a MacBook Pro USB C charger. The label on a charger says that it can provide three different power profiles: 20.2V - 4.3A 9V - 3A 5.2V - 2.4A There is a ton of ...
5
votes
4answers
738 views

Why did my homemade PCB turn out like this?

I did a first experiment with the UV-lamp + Transparency + Presensitized-Board method. Using a randomly drawn pattern, this was my (promising but unsatisfactory) result: What could typically be the ...
5
votes
6answers
2k views

Would it be possible to make a solid state transistor by hand?

I am curious, would it be possible to fabricate a modern BJT/FET transistor with hobby/garage tools only if size and aesthetics was not important? Which materials would one use and how would one ...
5
votes
3answers
262 views

What kind of equipment would I need to apply nonpermanent extension wires to test points of a PCB so I can access them via a microcontroller?

This is a DIY project. The title question is the first problem I'm considering, but the entire project is the goal I'm not an expert in hardware, but neither am I uninitiated. Put me at around an ...
4
votes
4answers
50k views

Mains LED light bulb flickers when switched off [closed]

We have LED bulbs in our apartment. In the bathroom, the bulb flickers on and off when it's switched off. Same when it was a CFL bulb before I switched to LED cause I hate CFLs. Our mains voltage is ...
4
votes
2answers
915 views

Most efficient way to power a 5 V circuit from a 14.8 V battery

I am making a DIY Raspberry Pi laptop. So far I have found a suitable board that will drive my display (M.NT68676.2A). From research I have found out that it will run off of anything from 12 V to ...
4
votes
5answers
142 views

DIY generator. Simple and small

I have read many posts on this site and everyone seems very competent, so here I am... very new to this. I'm trying to learn how to convert a motor into a generator. I'm just getting a bit overwhelmed ...
4
votes
1answer
580 views

How to apply solder paste with stencil in a 2 sided PCB?

I have seen lots of tutorials about how to apply solder paste using a stencil, but all of them only show how to apply the stencil to one side of the PCB. My current project is 2 sided and I would like ...
3
votes
3answers
1k views

What are an amateur's options to put a high-end IC on a board? [closed]

I'm actually an experimental physicist who does software-development for a living. So my knowledge basically stops at writing micro-controller programs and putting them on a breadboard, and hooking ...
3
votes
1answer
537 views

How to find connections on board? - DIY Keyboard from Old Laptop

I have a project that I have hit a wall on. I need your guidance! I need to find the spots on the board for the 4 USB connections. The attached photo is of the board. There are 4 connections I need ...
3
votes
3answers
7k views

How do I check polarity on loudspeaker?

How do I check the polarity on a loudspeaker? I have an 8 ohm 2 inch speaker with no wires soldered into it and the terminals have no markings. How do I know which of the two terminals is positive ...
3
votes
3answers
1k views

Is my PSU design safe, what should I change?

Normally I would just go and breadboard the design out, but since this is using mains power, I would rather ask experienced people first. I want to build a desktop 170V DC power supply to fiddle ...
3
votes
1answer
19k views

Diy 18650 4s battery pack [How to charge, how to build?]

I'm building a bluetooth portable speaker. However, I have some questions about building my first 18650 battery pack. I have 4 pcs of Panasonic unprotected NCR18650B 18650 3.7V 3400mAh. My goal is to ...
3
votes
2answers
462 views

Connecting home elliptical trainer to TV power

I'm attempting to use a TV addiction to help motivate an exercise routine. To do this, I am going to connect an elliptical trainer to the power of a television set (flatscreen). Here is my plan: I ...
3
votes
1answer
759 views

Maximize efficiency and brightness of diff color, cheap, 5m 5630 SMD LED strip lighting

I'm a science teacher and we are going to explore different design/effects of grow-light setups this year in class. I've gotten some great ideas for this project from reading from this stackexchange ...
2
votes
4answers
2k views

UV solder mask sticking to cover instead of PCB

I'm doing the usual DIY PCB process. Lately I got some of the chinese UV solder mask (similar to the one used in this video). I can work with it just fine - it sets under my UV lamp perfectly, within ...
2
votes
3answers
6k views

Safety when using ATX power supply as benchtop supply

I found many pages where people convert an ATX power supply to a benchtop power supply to give 12, 5, 3.3V. However the current output can be very high (several amps). When using this and you NEED ...
2
votes
2answers
3k views

Problems trying to wire a USB-C cable

I have been trying to figure out how to custom wire a USB-C to USB-A cable for a while, with no luck.I have tried some different connectors, but wanted to get some outside ideas on what I might be ...
2
votes
3answers
6k views

50W Amp for 15W Speaker

I am building a portable speaker and I am looking for a decent amp for my two 15W Phillips speakers. It is tough to find an amp that is efficient and cheap so I was wondering if there is something ...
2
votes
2answers
316 views

Is this an RC filter in the circuit for a nightlight?

So there is this nightlight (a little flower that you plug in directly into a mains socket and switching it on gives you some light to light up your bedroom at night) which I dismantled and tried to ...
2
votes
2answers
515 views

Satellite detector and a mobile phone

A satellite dish with LNB connected to a satellite detector when powered by a 18v source could detect radio waves from satellites. I made one using the ppt here. The detector, (when it was not ...
2
votes
2answers
1k views

Help with fixing LED night light that won't turn off

Software guy here, with limited practical electrical engineering skills (barely used a soldering iron since the university). :) My daughter has a LED night light using inductive charging. After ...
2
votes
5answers
240 views

How to power up 50 LEDs? (DIY 'fireflies' project)

I want to install lots of tiny LEDs lights in my garden (at least 50). I DON'T want high voltage cables in my garden so I am thinking in getting a high power, low voltage transformer to power up these ...
2
votes
3answers
351 views

Put outputs of 2 computer power supplies in series?

I've been working to figure out an LED lighting project for my classroom for a while now, readings on this site has helped. One part of the solution is to combine in series computer power supplies (...
2
votes
3answers
3k views

An appropriate voltage regulator / limiter for a 5V solar panel for USB charging?

I'm building a USB solar charger for my tablet, which has so far worked well. I'm using a 5 Volt, 5 watt solar panel (same as this one), which outputs about 4.5V and 0.6A in real use when charging my ...
2
votes
2answers
327 views

Google Glass 3.5mm jack with battery neck strap

I'm thinking of improving my Google Glass by DIY building a micro usb to 3.5mm headphone jack with a battery connected to a neck strap out of parts from the internet. I've already built the neck ...
2
votes
2answers
580 views

transformer windings

I have a 900 watts transformer from a microwave, this used to have a secondary voltage of around 2000 volts (for the magnetron) but I removed it. I wonder if by using 15 turn secondary that will give ...
2
votes
1answer
290 views

What causes failure in longer USB cables?

I wired up some USB-C 2.0 to USB-A 2.0 cables, and tested the maximum length I could get out of them when connecting a PC (host, USB-A) to an external hard drive (device, USB-C). I got stable power ...
2
votes
1answer
3k views

Proper storage of ferric cloride PCB etchant

I etch about half a dozen printed circuit boards each year at home, using an aqueous ferric chloride AKA iron(III) chloride etchant solution. As I want to minimize the costs and hassle of buying new ...
2
votes
1answer
4k views

inkjet cartridge control [closed]

I would like to build this: https://www.youtube.com/watch?v=UjlHtHAN0DU I.e. a programmable stamp/printer that you slide along a piece of paper. I would like for it to use easily obtainable ...
2
votes
2answers
384 views

Acquiring an accurate clock input for my computer

Building a timegrapher is quite straightforward, it is nothing more than a piezo transducer connected through to an amplifier. However, in order to actually utilize the results, one need an accurate ...
2
votes
1answer
483 views

Metal enclosure for custom car stereo project

I'm thinking about developing a custom car stereo, and it surprised me that there's no DIY enclosures for this purpose. I've just found plastic boxes in the 1 DIN size which can be installed into an ...
2
votes
1answer
13k views

Making a [4-Pole TRRS to 3.5mm Stereo & Mic Adapter (Male to 2x Female)] from an iphone headphone splitter jack?

I want an adapter that merges the microphone and earphone 3.5 mm jacks into a single 3.5 mm jack ( basically I want to build the blue adapter thingy): I have an earphone splitter for iphones that has ...
2
votes
2answers
1k views

Is there a simple way to DIY a coaxial male connector?

I have a 12V power supply that has a female coaxial plug like the one on the right in this image: I rigged something up with tinfoil just to see if it would work, but it's not ideal at all. Basically,...
2
votes
1answer
14k views

Creating a home made ultrasound transducer

I don't know how ultrasound transducers (transmitters) are made, is it possible to create a home made ultrasound transmitter with a custom specific range 1MHz or more? If it is not, would a 3D ...
2
votes
1answer
2k views

What's wrong with my voltage multiplier segment?

The moment I learned about voltage multipliers I was really excited. What an awesome way to kill yourself! I found a high voltage multiplier guide and using the image below, I created my first ...
2
votes
1answer
153 views

Device power requirements

I am designing a device and I'm confused on calculating my total amperage required. I have designed this device to have 3 main circuits in parallel that all take 5 V from the same power source: ...
2
votes
3answers
260 views

Presensitised-PCB Build Method

After completing many basic circuits on stripboard and premade PCB I've decided to try my hand at making my own PCB. Following some other forum posts this seems do-able but will likely take some trial ...
2
votes
2answers
727 views

Smallest 2 Pin AC outlet socket [closed]

For a home automation project I need to source panel mounting electrical outlet sockets which are as low profile as possible and are rated at least 200 watts. Something like a female version of these ...
2
votes
2answers
1k views

Schematic for a lipo battery bleeder overcharge protector

OK, so I am building a 12v (really 11.1v) 10000mah lipo battery. I am going to use it on campouts to run things like 12v fans and car chargers and run other high-current devices that couldn't be run ...
1
vote
6answers
2k views

How can I build a simple USB signalling device?

I would like to construct a simple device that plugs into a USB port and sends the computer a signal (i.e just a 1) when a user presses the button or switch etc. I ...
1
vote
5answers
464 views

How to cheaply switch between two sets of 7-input-wires?

I am trying to make a water level sensor. I want to use a single circuit for two water tanks. For this I need to be able to switch between two sets of 7-wire-inputs to the circuit (the 7 wires that ...
1
vote
1answer
89 views

SMD transistor die vs DIP transistor die [closed]

Is the die of SMD transistors different from die of DIP transistors with a unique part number? Is the power transmission of a transistor dependent on its package type or chip type ?
1
vote
1answer
183 views

Interfacing RAM to a DIY computer

I am a relatively newbie to electronics but hopefully this question is not very non sensical: I am following a guide to build a 8 bit computer. The guide requires a RAM which has a 4 address bit and ...
1
vote
3answers
821 views

Automatically measure voltage over a wide range

There are voltmeters that can measure voltage over a wide range without the need to switch the range manually. I'm quite curious how do they do it, because I'd like to make a tiny device capable of ...
1
vote
2answers
486 views

Astable Multivibrator not oscilating

I am pretty new with this stuff, just learning. I wanted to make a simple PCB, and as this was my first project, I decided to go with astable multivibrator circuit, to oscillate 2 LED's using ...
1
vote
1answer
2k views

Can I charge a 12V 2A NiCd battery with 18V 14.6A?

I have a 12V 2A NiCd battery which I want to charge. I have a power unit that puts out 18V 14.6A. Can I use it to charge it? Would the battery just draw the current it needs or would it always put ...