T&L Publications

For safety's sake I wouldn't use a foot pedal. I'd rather have dual pushbuttons separated by at least 2' so I could be reasonably sure that the operator's hands were clear of the saw before it was powered on. Don't forget that your Panic switch should be big, red, and have no electronics associated ...

Tony, it looks like you need a "star ground." The 28V circuit should have its own large gage ground wire and the 3.3V circuit will have its own small ground return. These grounds will connect to the battery at one point only . This will avoid the current in one ground return affecting the ...

If they are lead-acid batteries, this is the simplest way.

I worked with someone who did this with NiCd batteries to charge individual cells of the battery to get maximum charge-per-cell. We used FETs instead of relays to save on weight and power, but the concept was the same. Works fine.

-lyndon

Time & temperature are trivial. As you stated, time can come from the PC. Temperature can be read by any number of sensors on the market at fairly low prices. A long time ago I used to make an RS232 temperature sensor that was sold to sign companies (including Yesco that does the huge las Vegas ...

Bigglez: I think that's a bit unfair. When we work on our pet projects we aren't comparing the time spent to what we could go out and sell it for, we're comparing it to watching TV or reading, or going for a walk, etc. In that case the time has little monetary value, but it's comparable to other for...

Kurt: This may be heresy on this board, but for the $60 cost of that kit, you can get a few PCBs professionally made and the quality will be light years ahead of anything you can do at home. Some folks like expresspcb.com, others use batchpcb.com and there are tons more if you just google cheap PCB....

I don't think you're likely to find this since from my experience, the aftermarket uses plug in EPROM or Flash chips that replace the OEM chip rather than reprogramming it. That at least implies that the OEM device is a PROM rather than Flash. I recently had to have my wife's 1999 F250 7.3L PSD (sou...

That seems awfully complicated for what should be a simple task. Assuming you are using white LEDs (it's a lamp after all) why not use three in series with a dropping resistor? Out the box you'll be around 70% efficient if your PS is indeed 15VDC. Doing it "right" with a constant current s...

If you are building a controller for the stepper motors then you would already know how fast they are running. It seems that you wouldn't also need to measure their speed, just display it. That should be a much simpler requirement to meet. What are you using to set the motor speed?

It will work just fine. I found myself in a similar situation about 2 years ago. Atmel has an appnote on converting from the 90S2313 to the Tiny2313. For most applications, the only changes are in the fuse selections: i.e., limited to at most one byte. The startup time and internal/external clock se...

The company I work for has a subassembly in a larger machine that is similar in size and must be kept at around 10 deg. celsius. We use three large (about 3"x3") Peltiers, but I don't remember how much current they use. I do remember that it's a lot and I vaguely remember writing the code ...

I haven't read the article, but if its just ISD sound recorder chips you need, I think I have a few of those modules lying around. If you want them they're yours.

Sophia: Does it have to be an SMS message? Would a message like a business card or a note sent over Bluetooth be OK? The reason I ask is that a lot of laptops already have Bluetooth built in and if not, you can get a Bluetooth card for a computer for a lot less than $200 I have one from Office Depot...

Rabbit semiconductor and Digi International have a few programmable boards with webservers onboard. Plug into your router and do the deed from a browser!!

Ihave a friend who's used one of the Rabbit boards and he says it's really easy to get going.

This is fantastic. Every so often I want to pot an electronics project, but I'm too cheap to buy a bucket of Master Bond potting epoxy ($50 a quart!). If hot glue or silicone will work without corroding leads, that would be great. I have used Master Bond before and it works great, just too expensive...