General Part Scavenging

I searched the forums about general parts scavenging and the last conversation took place 10 years ago. Technology has changed drastically since then so I am just seeing if anyone has Ideas of great parts that you have/can salvage from broken or discarded devices. As I am currently living the social distance life, I wonder if there are some cool parts right under my nose.

I have an old DirecTv remote sitting around and we don't have DirecTV anymore so now I am kicking myself for throwing electronics that could have had a receiver in it. I don't post very often in the forums so if I have this in the wrong place or did any other taboo, let me know and I will remove it.

Anyway, let me know what is out there. Do not assume my time is worth anything. I don't care if I can buy the part for $1 and it would take me an hour to remove.

I've gotten a couple roadside pickup TVs (beware the HV section) and got the IR receivers and small I2C EEPROMS out. Sometimes the buttons are all together on one circuit board - if you're into analog switch trees. The boards are usually loaded with electrolytic caps and various oddball value resistors.

Got a 512K EEPROM from an old motherboard.

Some of the old car radios have encoders for the channel select, or whatever. Small channel memory EEPROM. Maybe a small DC motor for cassette drives.

Dehumidifiers have a board with an EEPROM and/or a display board and wiring going to remote sensors, like tank full and motor controls.

Some paper shredders have an IR sensor on the feeder and a fairly stout motor.

Photo resistors (as opposed to photo diodes and photo transistors) are now (AFAIK) effectively banned because of their toxic content (cadmium). Salvaging these may be "profitable". I have heard that these have nice spectral properties (sensible for the same frequencies as the human eye). Or possibly I am wrong ... ;-).

Just yesterday I took apart an old vacuum. Power cord is useful, the motor we kept (I should power it up, check if it actually runs), the castors of the body seem useful (the body itself was too awkward a shape), and the vacuum hose itself will be put to good use. The control board we binned. That shorted out which is why the machine was discarded. It was seriously potted to boot, impossible to see what's even on it.

I don't find it very useful to try and harvest electronic components from circuit boards. They may or may not be broken, and new ones are so cheap... often simply not worth the effort of desoldering.

CdS cells are popular for being dirt cheap (as in 2-3 US cents a piece) and very easy to work with. It makes for a fine light/dark sensor.

I read somewhere that the vaccuum motors usually are universal motors capable of running on both AC and DC. Do you think you can run your motor with DC and how many volts would it need to run?

That vacuum motor is now somewhere in a landfill :-)

I don't know of the existence of such universal motors. I suppose a vacuum cleaner has simply a single phase induction motor, the speed control looked like a standard TRIAC based chopper circuit. A coil reacts very differently to AC and DC and the magnetic fields of course are also dependent on the direction of the current, making me wonder if it's even possible to run an AC motor on DC or the other way around.

Universal motors

Interesting. Thanks!

Thinking of what I have taken apart in the last year or so....

Printers are one of my favorites to take apart as there are normally several motors with gears that can be reused into other moving projects. Old tape players are the same.

If you can get old projectors they have some great lens on them. Often a squirrel cage fan which is hard to find now days.

Microwave ovens have a good slow motor at the bottom and a fairly decent fan in a housing. If you take the door apart you get a chunk of metal with a lot of holes that can act like a sturdy screen tray. The clear glass in the door is often in a pretty good mount that can be reused as is. There are often a few buttons that tell it when the door is closed that are useful. I have never had much luck with the touch pads on those. The thermal fuse thing can also be useful in some projects to protect them from burning up. Also the plate in the bottom that turns save the ring with the wheels and you have a poor Lazy Susan. If you have a wood working friend with a lathe the plate can be mounted up on a few wood rings the right size for a good lazy Susan.

A lot of the above have good power cords or plugs to plug on into. Also can often find interesting grommets to run wires through metal plates and misc plastic and rubber things to dampen movement and sounds. Plus a nice pile of screws and some bolts and nuts.

Power supplies from old computer towers are a classic to make a table power supplies. Heard of people doing things with the hard drives, I have yet to though.

Pretty much any tech from the 1900s will be fun to take apart and will yield a nice pile of useful parts.

The new small tech like smart phones I have had very poor luck trying to get anything useful. Heck the last one I took apart I never did find the motor that made it vibrate.

Newer car radios are also a poor one to try and get parts out of. Unless I have another radio of the same make that needs a modal they are not worth the effort, though it is an education to learn how they change the CDs in those things and you will end up with a big pile of tiny screws often including some specialty ones.

On anything you work with keep your eye open for big caps and make sure the caps have been discharged before you cross the wrong thing.