good tear downs for beginners

[mahin300]

just what the title says, for getting parts and learning. It would help if it was hackable for learning
 budget is $20-$30 (us)

[JoeAtl30319]

VCR

[Nirios]

Old home stereos from the 80's to early 90's.  The heavier the better and can usually be had for cheap at a garage sale, especially if listed as non-working or faulty in some way.

[ablacon64]

Grab some walkmans!

[FenderBender]

Anything any everything...provided it won't matter if you can't seem to put it back together.

There are very few pieces of electronics that I own that I have not torn down. I'm trying to think of a list but there's so many possibilities because each item is going to provide you with different opportunities for learning.

VCRs are great because they incorporate a lot of engineering in general. Stereos. Anything audio is usually not too complicated and fun. All sorts of power supplies. Printers. Calculators. Radios. Routers Modems. Cell phones Whatever you can get your hands on!

Even if it's a cheap POS device, it will teach you something!

[Jimmy the Squid]

I have a habit of buying old power supplies from eBay to tear down. They're fun to compare, and some even yield useful cases for other projects. If you are patient, you can pick them up for a dollar or three with free shipping.

[Apothus]

It would be good to know a rough age group as well. If this is intended for someone under say 15 I would recommend cutting off the power cords, just in-case.

Something i found rather interesting a little while ago was the electric fly swatts that have been around the last few years. Cheap Chinese junk makes the circuit relatively simple and easy to follow with no IC's plus it can be a good example of a high voltage booster circuit.

VCR's as everyone has said are good fun because they have a few unique components that are interesting to look at, especially some of the video head motors, the tape loader mechanisms etc. I would not waste much time on large integrated items like video players because they are all ic circuits and relatively uninteresting. There are also some interesting kits available in the price range which may still be worth considering.

A cheap multimeter is another interesting one. I tore down a toaster oven the other day and i even found that interesting so there is plenty out there.

[Mechatrommer]

anything that broken is, you own or from dumpster. its free and in case you damage it, its already broken

[NiHaoMike]

Look for a cheap wireless router that supports OpenWRT and/or Tomato Linux. (DD-WRT is too limited for advanced tweaking. I would highly recommend one that supports Tomato since it's both highly tweakable and useful in a "production" system.) First, get a serial connection to it with a FTDI cable or MAX232 (or equivalent) converter. Then look into stuff like adding a RTC or SD card using the GPIOs. (That involves more software than hardware, but it's still fun!)

If you're interested in high voltage stuff, old CRT TVs are very commonly available for cheap or even free. The degauss coils are a great source of wire for winding your own transformers and inductors. Also, you can look into getting some broken LCD monitors or TVs and learning a little fixing them. (Just beware that after you open a few, it's not that interesting except for the odd ones.)

Something else to look for is an old UPS. Lots of nice power electronics stuff and chances are that the electronics are still good since they're usually thrown out when the battery fails.

Also check garage sales, especially if you live near a technical college. A friend of mine once got a whole box of assorted circuit boards for $5, including a few PIC development boards he was looking for. He gave me the boards he had no use for, including an induction motor drive board (which turned out to be broken, but there were a lot of useful parts), several MSP430 boards, and even a few Cirrus Logic MP3 eval boards.

[mahin300]

Thanks everyone I found a VCR like what everyone said. Also. Found an old monitor witch works thanks guys

[NiHaoMike]

Something fun to try is to connect the VCR to the monitor. If the monitor doesn't already have composite or Svideo input, it's not trivial. A FPGA (with TMDS output) along with a video ADC would be an "easy" way to do it.

[westfw]

For quite a while, my favorite things to take apart, in that they actually had potentially useful parts, were CD drives from discarded computers.  A typical CD drive has three motors (spindle, tray, and head) (frequently of different types), an audio amplifier, a laser diode, some gears and mechanics, a couple strong rare earth magnets as part of the head fine-movement mechanism, plus the usual contingent of random electronics bits.

In general, a discarded computer has a lot of interesting parts, often moreso in the edge components (power supply, cd drive, disk drive, cables, leds, switches) than in the "main electronics" section.

[blackjames]

smoke alarms are a bad idea, because they have some radio-active thing in them. it freaked me out when i took one apart

[ThievingSix]

smoke alarms are a bad idea, because they have some radio-active thing in them. it freaked me out when i took one apart

I wouldn't worry too much, smoke alarms use alpha-emitter sources and most of the radiation is absorbed in the plastic housing. Once taken out, even if you ate the alpha-source the ods are nothing bad would happen because the amount of radiation emitted is so low. Remember, the Curies played with radioactive materials before they were mainstream, and in much higher concentrations.

On a side note however, i take everything that breaks in my house apart, from old video cards, to power adapters, led fridge magnets and everything in between. Its not hard to find things to take apart, as long as your careful you can always put it back together. Although i'd advise strongly against it, i've even screwed around with the back of my house switchboard to see how everything worked, i've opened every power socket, data socket and intercom port in the house, and i've even taken apart printers and an old radio(which leaked a strange fluid on me, to this day i have no idea what it was, although i assumed it was battery acid, but the batteries appeared fine).

[PA0PBZ]

Remember, the Curies played with radioactive materials before they were mainstream, and in much higher concentrations.

Yeah, and that's what killed Marie...

[trilium]

This is sort of a related question, but would salvaging old resistors/caps from scrap electronics be a good or bad idea?

[SeanB]

I do that all the time. You may not get the exact value you want, but often you get close enough. Used 2 yesterday to fix crappy OHJ battery chargers for cordless stuff, to make the batteries last longer as they are grossly overcharged at too high a rate.

[ablacon64]

This is sort of a related question, but would salvaging old resistors/caps from scrap electronics be a good or bad idea?

No problem with resistors, ceramic or tantalum caps are OK also as well as ICs, but electrolytic are a problem.

[G7PSK]

Remember, the Curies played with radioactive materials before they were mainstream, and in much higher concentrations.

Yeah, and that's what killed Marie...

Marie curie was 67 when she died so there is no saying if she would have die from cancer if she had not messed with radiation, she certainly could just have easily developed cancer from the other chemicals that she used in her research. Also the radioactive materials she had were by the ton, they went through tons of pitchblende and yellow cake just to get a few grams of radium throwing the uranium aside as of no interest to them.

[PA0PBZ]

From wikipedia:

Marie visited Poland for the last time in early 1934. Only a few months later, on 4 July 1934, Marie died at the Sancellemoz Sanatorium in Passy, in Haute-Savoie, from aplastic anemia contracted from her long-term exposure to radiation. The damaging effects of ionising radiation were not then known, and much of her work had been carried out in a shed, without the safety measures that were later developed. She had carried test tubes containing radioactive isotopes in her pocket and stored them in her desk drawer, remarking on the faint light that the substances gave off in the dark.

But there's no way to be sure of course.

[twbranch]

In the US go to a goodwill thrift. Tons of VCRs or stereo equipment to mess with. Thats how I got started in electronics years ago.

[NiHaoMike]

This is sort of a related question, but would salvaging old resistors/caps from scrap electronics be a good or bad idea?

No problem with resistors, ceramic or tantalum caps are OK also as well as ICs, but electrolytic are a problem.

Almost any part can be desoldered and reused, just beware that it might not be good. Test before using.

[twbranch]

I reuse a lot. I work on a lot obsolete equipment and some parts are proprietary. Having a donor unit helps out in those cases alot.

[JuiceKing]

L