CDs photocells, fir shame! Not very WEE/RoHs friendly are we?

Do you really understand what RoHS means?

It means you can now throw electronics in the trash instead of recycling them.

More important, it means that there is no more lead in the solder used to make electronic devices. Good, yes?

No. Very much no.

It means that a TV or any other device made from now on will last from 5 to 10 years, 10 years max, before it fails, and then it will be thrown away. It is a boondoggle for electronics manufacturers. And it's because solder without lead makes whiskers. This used to be a small problem when parts were large and well separated, but now parts are very small and close together. So when a tiny whisker grows from the tin, which it always does, it has a very good chance of touching another trace or part. And then, things stop working. Right now. No repair is possible.

RoHS is bad. Wasteful. And the manufacturers love it, because every TV, radio, cell phone, and even satellite, will have to be replaced in 5 to 10 years, instead 20 or 30.

Thank you European Union.

tom
K0TAR

Very cool but not my thing.Matthew T. Gossar

Hate spoil the fun, but RoHS compliancy doesn't mean you can throw your electronics to trash. It is just that this kind of improper discarding is not that harmful for the environment as would be if the solder material would contain lead.

Whiskers are not a problem with modern solders. After studying the reliabilities of lead free solders about six years, none of the studied materials presented whiskers. And this was done on flip chip connections, which are scale smaller than current smd so whiskers would've been more than noticable.

Main reason for current electronics not lasting longer than about 5..10years is the half ass job done in designing the products in first place. The curse of mass production; buying new one is cheaper than repairing. Mainly due to popular demand of cheaper products.

@Tarball:

It is funny to read what you think about RoHs, but your thoughts have no contact to reality. First, RohS didn't allow you to throw things in normal trash. Second: Electronic devices will only last 10 years in future? Wow, that means, the average lifetime will be doubled.

Please don't tell people they should not talk about a topic if the don't understand it if you do not understand it yourself. ;-)

Why is everyone such a nature-nut here? Your rhetoric borders on hysteria.
I highly doubt any of you have stopped driving your cars, stopped runing your computers, stopped playing your stereos, stopped heating your water, stopped turning on lights when its dark or made any other significant lifestyle change.

Lets talk about Pocket Theremins, not some tiny piece of electronic waste. How about you tell me how yours works?

This is a great article. I've always wanted to create my own electronic instrument and this is IT! THANK YOU and YOU ROCK!

HOWEVER, I have a few questions. On the bottom chip is a .01uh thingy and above it is a joint without(what my guess is) no solder/icon/bullet icon thing-a-ma-doowee. What gives?? Everywhere else I can see black-bally solder joints. HELP!

Also the 5k potentiometer... It has three parts I can solder wires too. How can I find out where I connect the wires?

PLEASE HELP! I failed this weekend due to a lame solderer and oh yeah, the schematic doesn't tell you which end is up on the chips soooo, yeeeah. My first attempt didn't make it past the leggs falling off of the chips, (careful, they are thin and break easy) but even if I did finish it and it followed the schematic exactly, I wouldn't have known that my chips were upside-down. Fortunately I found a site about the 555 chip and my second try will hopefully work... hopefully. :)

Oh, and by the way, the chip has a inset curve on one end... that's the top where the ground and power go. That's for any future DIY-fers needing to know.

1) The "bullet" is a junction point. That dot is telling you that you must make an electrical connection there (i.e. solder the wires together). If the wires cross and there is not a dot, then they should not be connected.

Be careful, though, some schematics are sloppy and don't always make things clear. Also, some schematics will have a little "hump" when two wires cross (but don't connect), to make it easier to determine if it's a junction or not.

2) For pots, you're always going to wiring the center pin, that's the wiper (the arrow in the above diagram). Your other wire will go to either the left or the right (viewing from front/shaft), depending on desired behavior.

If this is a volume control, I'd say put it on the right, that way your resistance goes down as you turn the pot clockwise (lower resistence, in this case, means greater power to speaker = louder). Worst case, you'll wire it backwards and the sound will go down when you turn clockwise. Just swap the sides. Pots are pretty hard to kill at these voltages.

3) I'd recommend picking up a little "breadboard" and using that to practice with, as you can focus on the circuit and not your soldering skills. Once you have it breadboarded up, and have it working, then you can solder it up.

Also, see if you can pick up some sockets for the chips. That way you can solder things together and not have to worry about overheating the chips in the process.

4) The 555 has been around since the early 70s, so there's a lot of documentation out there. Very widely used for blinky-stuff, etc. I've found this site to be very helpful: http://www.kpsec.freeuk.com/555timer.htm

We need to treat the earth better or we all die!!! Recycle ur stuff, don't trash it!

This is awesome. A simple Theremin operating on 2 timers. I love it. Having built some more advanced Theremins it's nice to see an easy, simple design like this.

Honestly people this is simple electronics and you can put it together in less than 30min. In fact with little effort you can just output the output of the Theremin to a stereo system line in and give the neighbors some interesting sounds.

Many thanks Dave.