T&L Publications

Soldering Tip - When you finally get a PCB, tack 2 diagonal corners of the chip down. Then from the opposite corners QUICKLY run a fine blob down the entire side of the chip both sides. Use 0.9mm solder or finer. Then using De-Solder Wick, quickly suck up the excess solder. The surface tension shoul...

A complete set of â„¢Picaxe Code, examples and uses can be found in a PDF document called "picaxe_manual2.pdf " it can be downloaded from the Rev-Ed website < www.picaxe.co.uk >, try page: 57. "PWM" can be used on the 08 and 08M chips (I/O Pin-2 / Leg-5). Your application is fair...

The simplest way would be something like a PICAXE. They are a PIC micro re-marketed as a picaxe, have their own bootstrap loader built in, software is a free D/L and they only need a simple D/L circuit using 2 resistors. There are trade-offs e.g. less program memory, but the Picaxe Basic was designe...

A LASER Diode does not work quite like an ordinary LED. They usually need a constant current to function correctly. If you didn't get a Specs Sheet on the unit I would be doing a search on it or similar units and see exactly what supply they require. As you said they are expensive, would hate to see...

I have written an article for N&V and a few for Australian magazines. You should include everything from the initial idea to final testing and assembly in reasonable detail, remember also there may be young hobbyists who don't have a clue, you need to cater for them also. Keep it simple and conc...

I had a relay circuit in N&V APR 2005 p:50. The op amp circuit in there charges up a capacitor which turns on a small MOSFET to latch on a relay for a second or so (microphone version). This may work for what you want, just change the cap value and or the bleeder resistor on the MOSFET or omit t...

You can buy off the shelf devices called (SSR) Solid State Relays, they have a Triac inside which is switched via an optocoupler. LED voltage, input = 4 to 40V DC using current limiting resistor.(input usually 20mA MAX) They come in 2 standard forms usually - PCB mount which handle up to 3A 240V or ...

There is a re-marketed PIC chip product. They call them a PICAXE. They made these simple enough for 12 year old students to program. It's still a Pic Micro, but it has a different interpreter actually loaded into the chip itself. They have written a new programming language that children can underst...

I was thinking the same thing,
Torturing an AA Cell like that.

Sounds like a bad earth/gnd connection, the hinge being the connection point. Maybe strip the hinges down and use graphite or ground up pencil lead instead of oil. Laptop hinges can be a pain, too lose and your screen slams shut, loo tight and stuff snaps off like motherboards, mountings etc. Its a ...

Sometimes its useful to have a servo able to
fuly rotate or just keep going.
They can be stepped slowly, accurately, if
needed, FWD & REV,who could ask for more.
And all this on only 3 wires, Pos, Neg, CTRL.

If using Internet Explorer later versions go to the Tool bar ^^^ up top select "Tools" -- Dropdown menu, last option - "Internet Options" -- under the General Tab middle of the window "Temporary Internet files' section select Settings try moving the Temp-Int-File to your des...

Running hot water through most rigid plastic
tubing does wonders to soften it.

Is it actually a Dynamic Speaker e.g. Cone, Magnet and Coil or a Piezo Element ? If you can find another speaker to fit inside the case you have, just rip out the old one and replace it, use the same case. Some headphones may be a similar in size. The enclosed case may help the sound to be projected...

I have done a few of these for friends. Both phone packs and power tools. They are usually fiddly as hell. If you manage to crack the case open without too much damage you are half way there. Replacement batteries can be obtained with s/steel solder tags, you need to get that type mostly. You may al...