Frankenstein's Components.

[(*steve*)]

Based on a suggestion, I am starting this sticky thread.

What I want it to contain are posts that reveal an unusual source for components, or an unusual use for components, or things of that vein.

I expect the first will have something to do with optical mice...

I really don't want this thread to include discussion, create a new thread if you want to do that. This one is for a list of weird and wonderful ideas.

 

[GreenGiant]

Lets start out with some inspiration. Something that I saw a couple years ago that I found completely mind blowing that I still refer back to on occasion.

Johnny Lee's use of a wii remote to make something really expensive out of something not so expensive. I know most of you have seen probably seen this before but I still want to share.

Enjoy!

 

[Miguel Lopez]

My Excalibur

I think this is very weird.......my two Excaliburs........and my source of flux.

 

[BobK]

I would like to know if anyone has taken out an LCD screen from one of those incredibly cheap digital picture frames? If so, what kind of interface does it require?

Bob

 

[Raven Luni]

Cant say I have, but I've got a bunch of psp and nokia screens. I'm guessing it will probably be DSI or one of the related standards. I managed to acquire some of the specs for that (before writing a lengthy facebook rant about how some companies develop 'common' standards but only give out the information to 'big companies' and therefore stifle enterprise in the case of individuals and small businesses)....

anyway....

 

[Raven Luni]

I think the humble PC power supply deserves a place here. I recently bought a 200W bench supply for about 40 quid. It was a piece of crap and fell to bits on the first use (see mortuary thread). In contrast, I just bought 4 300W ATX power supplies for less than that (in total - £8 each). Lets compare:

BS: 200W
PSU: 300W

BS: Single rail, adjustable 5-15V, 0-15A
PSU: Multiple rail, fixed (+3.3V, +5V, -5V, +12V, -12V), 20A

BS: Digital readout of voltage level and current draw
PSU: Just a box with wires

BS: Plastic enclosure, not earthed, fragile controls not fit for purpose, tamper-proof design
PSU: Earthed, metal enclosure, can facilitate common grounding, can still open easily even if youre not supposed to

BS: Not externally controllable
PSU: Standby power (+5V, 2A), externally switchable

BS: £40 (approx)
PSU: £8 (approx)

Overall:
BS:
PSU:

 

[GreenGiant]

I was actually thinking about taking an old power supply or two (probably pulling from computers found at the local dump) and modifying them for use as power supplies, I mean it would be basically free, just need a little modification

 

[Raven Luni]

It seems the current and voltage display for that bench supply comes in the form of a neat little self contained meter module.



It runs quite happily off the 12V rail. Those readings in the picture appear to be the default values when the measurement pins arent connected. There are a couple of trimpots on the back which I guess are for calibration (and from tests I've done so far it looks like it will need a wee bit of tweaking).

Well I guess that answers the question of whether to repair or harvest Now I can grab those nice big inductors for my buck regulator .

 

[quantumtangles]

Microwave ovens, broken printers and motherboards

Microwave ovens are dangerous to take apart even if you know what you are doing...those massive caps can zap you long after the machine has been unplugged...but they contain a wealth of useful parts for safety qualified engineers to loot.

One of the most interesting parts to my mind (of the many in these devices) is the piezo-electric component. You can use it to make a crystal earpiece if you remove it very gently. I should add that I have never looted a microwave oven myself because the super-caps are a bit scary.

Broken printers are a good second. Stepper motors can be expensive to buy from new and great for robotics projects. Some nice caps in there as well.

Last but not least, broken old motherboards...seemingly uninteresting because of all the dinky micro-components (...note that you can remove and re-solder even tiny surface mount components if you have a hot air gun and solder paste) also have lots of high end electrolytic capacitors great for the parts bin.

The really old motherboards (such as Pentium II Dell motherboards for example...photo below) have high end golden colored heat sinks. Magnificent for quality DIY amplifiers. These heat-sinks might cost £60 or more on Ebay ($100) from new . Massive and exceptionally cool

Peripheral boards from late 1990s and early 21st century motherboards often have small 12v fans and if you look closely you will see that they have their own lovely little heat-sinks over the fans. These little 12v fan heat-sinks are great for 20w DIY amps like the little amp I made last month from odds and ends

Forgot to mention cathode ray tubes from old black and white TV sets (and old color TV sets too). If mains electricity safety qualified and looking for a retro look, you could remove the CRT completely from the old set, hook a DVD player up to the connections at the base of the tube, and watch old movies through a very retro looking CRT tube. You can also do this with certain types of old oscilloscope CRTs provided the trace materials inside the tube (the Phosphorous) is not the long lingering radar kind. Green TV. But you need to know what you are doing (I have not tried it) and should not attempt this unless a qualified electrical engineer.

Really this is the last one. A zany project on youtube makemagazine for a laser transmitter. The laser is wired to audio input (e.g. a radio station). You fire the laser beam across the room towards a solar cell. The audio signal within the laser beam is picked up from the positive and negative tabs of the solar cell, amplified through a conventional amplifier and made audible. Light radio (always use eye protection with lasers as they can cause temporary or permanent blindness, even the ones from old dvd drives.

 

[GonzoEngineer]

Setting the bias voltages on the grids of a vacuum tube using the voltage drop of LED's. (hard to find exact Zener Diodes for specific applications.)

 

[pyromaniac4382]

Heat Gun

In the past year I came into the possession of a Wagner Heat Gun. A simple two setting heat gun, but it packs a punch. I normally acquire things people are throwing out, such as TV's or electronic toys and sit with a ceramic mug to hold all of the parts I scavenge off of the devices. I wouldn't suggest doing this inside a closed space. There are some funky smells coming from burning components and PCB boards. This may not be the most elegant solution, but it sure beats trying to de-solder things one-by-one when you can just pick them off.

A great source of components are old routers, and computers. The older the better. The older they are the more likely they will contain through-hole parts which are candy for some of us that don't have solder rework stations

I swear half the fun though is trying to find datasheets on components coming from these random things.

 

[(*steve*)]

Try not to burn the components

Other than that, I'll agree on the fun in the search for datasheets thing

 

[shrtrnd]

That Wagner heat gun is for stripping paint, not electronics.
Sure, you can use it, but you better heed *steve*'s advice. You'll be aiming at one component, and melt everything around it.

 

[eKretz]

I have successfully used a Milwaukee heat gun for all sorts of hot air rework. Mine has adjustable temp by 10° F increments though. And I made nozzles for it from sheet metal. Here's one about 10mm square:

 

[(*steve*)]

Looks interesting. What temperature range does it support?

Nice job on the nozzle.

Can you also change the airflow?

 

[eKretz]

It's adjustable from 70°F to 1100°F. Yeah the airflow has 2 range settings, the low one works great, the high one is a little overblown, forgive the pun, heh.

That nozzle was just a 10 minute quickie, but it works pretty well.

Edit: I actually just had it apart tonight, the LCD temp display was missing half of it's digits, so I yanked it apart and found a few wires that had popped off the solder joints on the board. Problem's gone now! But anyways, I was thinking about adding a pot to the blower motor instead of just the 2 position switch to get infinite adjustability. Do you think it would be worth doing?

Here's a shot of the LCD panel, you can control temp to within 10 degrees. You move the slider on the handle and the display switches momentarily to "setting" mode, then after a few seconds of no movement it goes back into "reading" mode. It's got a closed circuit loop so it can adjust temperature on the fly to compensate for the different airflow settings.

 

[(*steve*)]

Some posts moved to https://www.electronicspoint.com/adding-pot-hot-air-gun-control-airflow-t259242.html

 

[Gav1985]

I recently converted an old ATX supply. Each line has multiple wires (Each rated to 6A max I believe with the exception of the -12V. Didn't bother with the -5V). Simply modified the case to accommodate some binding posts, and fitted fuse holders on the 3.3, 5 and 12V outputs.

Connect up a simple flip switch and some STBY, PWRgood LEDs, and Bobs' your Auntie.
For a final touch, I spray painted the case matte black, looks awesome.

And, yeah, I got two ATXs from my local recycle yard, free , both worked but one was completely disgusting inside lol.

Total cost of the components I bought was around £10-£15 quid, which compared to a Bench supply from somewhere like Maplin (Easily £40-50 + )!

 

[glewis721]

Really old synthesizers are great sources of panel-mount buttons as they came out before tactile and conductive-rubber buttons. Old (like, really old) computer keyboards also sometimes have these.

 

[Raven Luni]

USB keyboards are handy if you want a quick and dirty interface. The LED's can be used for serial output or together as a 3 bit display giving 8 states. I'm planning to use one as a PIC programmer which I'll make another thread for. As for the keys, you can do anything you like - make a custom controller, drive them logically, one guy made a set of pedals...