|
Jairbrekr, I love you. clredwolf, that breadboard picture has me in stitches and remembering the good old days of TWO MILLION PROJECTS IN ONE electronics labs from Radio Shack!  For an excellent and humorous explanation of electricity and electronics, I recommend There Are No Electrons by Kenn Amdahl. Hell, for that matter his other books are a hoot, too. The absolute best beginner's reference by far, however, is unfortunately no longer in print, because Radio Shack betrayed us all and turned into a loving computer and cell phone store, the bastards. I'll never forgive them.  It was called Getting Started in Electronics, and I still have my copy from when I was a kid that I treasure. The whole thing is hand-drawn, hand-written explanations of circuits and components. It was only available at Radio Shack, and even had it's own PART NUMBER like everything else they sold.  Fake edit: HOLY poo poo YOU CAN GET IT FROM AMAZON ALONG WITH HIS OTHER BOOKS!!! I should really start building BEAM bots again...
|
#
¿
Jan 9, 2008 01:48
|
|
|
|
| # ¿ Apr 25, 2024 11:02 |
|
|
Insurrectum posted:If anyone wants a good small project to begin on, try the Mintyboost. It's a great, simple project that only costs $30 and is a good introduction to soldering. My first 'real' soldering project was a little FM transmitter with built-in microphone purchased from Radio Shack. I think they don't sell it any more. That being said, there are other options. Ramsey, for instance: https://www.ramseyelectronics.com
|
|
#
¿
Jan 9, 2008 05:22
|
|
|
SkunkDuster posted:With that aside, what the hell is the 5th band on this resistor for? It's been a while, and I can't find my handy dandy resistor chart from Radio Shack back in the day (it's so cute, it has a wheel you turn to get the color!  ), but I think that yellow band is an indicator of high wattage rating? It's certainly a big sucka.
|
|
#
¿
Jan 9, 2008 20:58
|
|
|
You need to write a book and put all these great diagrams in it, Jairbrekr. It could be called ELECTRONICS FOR FAGGOTS: HOLY TAPDANCING CHRIST LOOK AT THESE ELECTRONS. 
|
|
#
¿
Jan 10, 2008 19:39
|
|
|
Any of y'all gents old enough to remember... HEATHKIT http://www.heathkit-museum.com/ My dad grew up with it, and I have an old warhorse of a Heathkit bench power supply that still works just fine.
|
|
#
¿
Jan 16, 2008 19:57
|
|
|
I have one of these on the way: http://www.spykeeworld.com/ It was on Woot! earlier this week for less than half price, and I couldn't resist. I'm looking forward to hacking it, as there seems to be a pretty good community of people doing so. It has a 200Mhz ARM9-based Marvell System-on-Chip, Wifi, a camera, audio in and out, and is programmable in C# or C++. Ideas that I've had so far include: - Adding a USB Missile Launcher (http://www.thinkgeek.com/geektoys/warfare/8a0f/) - Articulation of the "head" which is where the camera is. Out of the box, you can only position it by hand. - An articulated arm with a gripper, which I may build out of LEGO using their new linear actuators, or I might just go for something from Lynxmotion or similar. The idea of remotely controlling this thing and actually being to physically interact with objects really appeals to me. - Expansion of the battery capacity/possibly conversion to lithium polymer batteries; the stock battery life is rated at only an hour, although supposedly it can automatically find its charging station when it gets low. - Give it a face: http://www.nkcelectronics.com/color-lcd-128x128-nokia-kn128128.html  Anyone else have one of these? I'll post pictures of the guts as soon as I get it!
|
|
#
¿
Aug 14, 2009 15:11
|
|
|
It appears to be a USB host, although I'm not quite sure of its capabilities in this area. The "head" which contains the camera and a motion sensor (and, I think, the microphone) connects to the motherboard via a mini-USB connector, but that doesn't necessarily mean it's a USB connection. Looking at the data sheet for the processor, it has some GPIO, serial, and JTAG. Other hackers have explored using the JTAG interface to flash the firmware. I'm not sure which ports are in use and which aren't, but I'm hoping I'll be able to get some insight into that by examining the motherboard. It just got delivered yesterday and I haven't cracked it open yet.
|
|
#
¿
Aug 19, 2009 13:13
|
|
|
I just won an auction for 18 pristine Russian nixie tubes for only $34 shipped. These are the type that face upward from their socket, rather than at a right angle, so I'll be mounting them in a panel to make a nixie clock. Updates and pictures hopefully to follow soon...although I do have to wait on them to get here from Russia, bummer.
|
|
#
¿
Aug 31, 2009 21:43
|
|
|
After some poking around and looking at various designs, I think I'm going to go with this solution for my clock: http://www.allspectrum.com/store/pr...IXIE-CLOCK-CHIP It's a pre-programmed microcontroller; just add the driver chips and not too many other parts besides, and you have a clock! I wonder how long it's going to take for those tubes to get here from Russia...
|
|
#
¿
Sep 2, 2009 13:53
|
|
|
If anyone experienced with building BEAM circuits could help me out with this, it would be much appreciated: With new and ridiculously tiny pager motors available now, I have embarked on a project to build really, really small photovore. I have some very small solar cells that I believe I can wire up in parallel as the power source, but I'm not sure if they're going to provide enough current for a Panasonic 1381-based circuit...they reliably put out 4V in bright light, but at only 1.6mA, and I have four of them. Assuming an ideal total of 6.4mA, is that going to be enough? It doesn't seem to me like those little motors are really going to require much current.
|
|
#
¿
Oct 2, 2009 13:55
|
|
|
So, my current project is assembling the parts to build a complete synth/noise generator with an SN76477 I discovered in my parts bin (some of which were inherited from a music junkie, so it makes sense). There's a great circuit for this here (at the top of the page, the 1978 Popular Electronics article): http://mkv.itm.miun.se/personal/per/diy/76477/ (page 5 of the article) Looking at this circuit and the SN76477 in general, I sense that it should be possible to digitally control it to a certain extent. At a very simple level, it seems like it should be possible to simply replace the rotary switches for selecting resistor or capacitor inputs with transistors, but a 4016 or 4066 analog switch chip might be better. Some of the inputs are simple selections which are obviously easy to control. Others...it gets more complicated... (see also the datasheet, for the interested) Some of the inputs are control resistors, which are used in combination with the capacitor inputs. I don't completely understand how all of this is working, but it's easy enough to see that you've got a bunch of potentiometers that are being used to provide variable resistance values (tied to ground) for these inputs. I can of course envision something similar to the switched banks of capacitors with resistors instead, but this doesn't appeal to me. I don't even know where to begin to come up with a digitally controlled variable resistance value for these inputs. Is this even possible? I've seen servo-controlled pots in home theater equipment, but I would guess that they're quite expensive and given the vast number of digitally controlled synthesizers on the market, someone must have come up with a solution for this already... EDIT: Well sheeee-it, this looks promising: http://www.analog.com/en/digital-to-analog-converters/digital-potentiometers/products/index.html Powdered Toast Man fucked around with this message at 19:59 on Oct 12, 2009 |
|
#
¿
Oct 12, 2009 18:31
|
|
|
So, to construct a keyboard for my synth that I'm working on I will be experimenting with resistance values for pitch control. To "tune" this, I want to measure the resulting output frequency, which I can then compare to the known frequencies of musical notes to get the fixed resistor values I need for each key. I do not, however, have a frequency counter. I do have a very nice, recently cleaned up and refurbished oscilloscope (it's a vintage Heathkit with a ton of nifty features), and a good digital multimeter (Fluke, unfortunately it doesn't have frequency measurement). Is there some way I could improvise frequency measurement with the tools I have, or should I be looking for a cheap, used frequency counter?
|
|
#
¿
Oct 15, 2009 14:14
|
|
|
Well, last weekend I learned how to use solder paste to do surface mount soldering and reflow with a toaster oven. I have to say that I couldn't believe how easy it was if you just use the right materials and tools. As my first project I put together a breadboard power supply module that runs off USB (it also provides a serial port). Money shot from the reflow here: http://www.youtube.com/watch?v=_5lksMvmqQc One pretty slick tool that was provided by the teacher was a laser cut mask, laid on top of the board and exposing only the solder pads. This allowed application of the solder paste with the edge of a piece of plexi, and just the right amount got on the pads. It is, however, quite possible to use a syringe for each spot if you're a masochist.
|
|
#
¿
Nov 17, 2009 20:12
|
|
|
I'm thinking about building a multi-station USB charger with micro-USB connectors. I've sourced some durable-looking PC mount connectors from Digi-Key and I've been looking at the pinout/specs for USB...do I need to do anything other than provide constant, regulated 5V? I'll be charging stuff like cell phones or accessories that have their own batteries and charging circuitry built-in.
|
|
#
¿
Dec 28, 2012 17:53
|
|
|
Parallel Paraplegic posted:I did something like this once, and yeah basically you just need a good steady 5V and ground and most things will just suck as much juice as they can. You might want to be careful in this regard as having many devices connected will suck a surprisingly high amount of current. The USB spec is only supposed to go up to 500 mA but some things can take as much as 5 loving amps when charging if they just try to suck up whatever is available, according to Wikipedia. Yeah, I have a Samsung Galaxy Note and it needs a 2.1A charger to charge effectively. "Normal" USB wall chargers are about 1A these days, it seems. I plan to put in sufficient protection for each individual connector, and the power supply section will be beefy. longview posted:Power quality is important for smart-phones since noisy power interferes with touch screens making them unreliable.  Holy poo poo, you just explained the mystery of why the touchscreen on my phone acts weird when I have it plugged in to a cheap rear end Chinese charger.
Powdered Toast Man fucked around with this message at 19:40 on Dec 28, 2012 |
|
#
¿
Dec 28, 2012 19:38
|
|
|
Well, I've always wanted to make my own switching regulator circuit. There's something beautiful about them (like the tiny Apple cube chargers). Could probably get a cheap surplus DC-DC converter, though.
|
|
#
¿
Dec 29, 2012 02:09
|
|
|
|
| # ¿ Apr 25, 2024 11:02 |
|
|
So, I've been trying to come up with a decent anemometer, since that is the only sensor that isn't easily available to connect to an Arduino or whatever. I've come across various options, but most recently I came into possession of a car stereo that had a rotary volume controller that I think MIGHT work...it's an ALPS rotary switch, but I have no information about the pinout. It has two pins on one side, and three pins on the other. My goal is to use this as a rotary encoder for measuring wind speed...any suggestions?
|
|
#
¿
Jul 14, 2013 05:11
|
|