T&L Publications

For the cub scouts pinewood derby track, I used a laser from the junk store, $2 each and I mounted it vertical above the track. In the track I had a visible light sensor with the laser pointed at it. That cost me <$3. I fed the light sensors into a micro and we could determine the winner and flash a...

Thanks for all the replies. I did use some of the ideas here. I am building the prototype this week. I will let you know....

I just do not get along with op-amps. I like them, they just don't like me. :) I need to take a 2.8vrms AC sine wave (7Khz), reduce the voltage to 500mv and invert the 500mv signal so I have two signals at same voltage, 180° out of phase. I know the good old 741 will do it. Can anyone point to an e...

It's mostly for convenience. If they get out in the field and realize they needed a different frequency, they have to order crystals from us and wait for shipment. I may just put 7 crystals on the board and a jumper to field select the frequency.

We use a crystal in one of our pc boards that the user can replace with different values to get different carrier frequencies. The crystals on both ends of the communication devices have to match. I would like to build in a programmable frequency generator, but it needs to be accurate like a crystal...

Forgot the software...

PC-DSOFT5 $395

Have you looked at a PLC yet? Go to www.automationdirect.com They have the best prices. Select a CPU type and add as many analog modules as needed. You could have relay or solid state outputs. The CPU will allow PID loops which is the type of control usually needed for temperature. A DL06 would prob...

I sent a picture out the guy in Wasington, thanks Ron H. I may get my friend at the high school science dept. to help with more tests. Thanks all.

My freind thinks he found a meteorite on his farm. It has to have iron and nickel to verify. We can make a magnet on a string move so we are sure it has iron. What can we do to test for nickel? Thanks.

I have a number of SmartBlock CPU boards. They are circa 1991. Never used. They have a Zilog Z80 micro, eprom, ram and RTC all on one board. Are these worth anything to anyone???

http://www.infoplease.com/spot/daylight1.html So.... How many products are going to malfunction next year because they were programmed with automatic daylight saving adjustments? Next year daylight savings changes by about a month. Congress approved it 2 years ago. My VCR was made 6 years ago. It au...

I ripped my ViewSonic lcd monitor apart. The backlight is intermittent. It will turn on sometimes, just not always and definately never twice in a row. It uses a TI TL1451A, buck boost chip. I see 12V on the chip and when working, I can measure the pulses that the chip creates. When the backlight is...

Thanks, Front Panel was it. I must have tried a hundred searches on Google but I kept getting cellphone overlay junk....

I remember a year or two back that some company came up with some free software you download and run that allowed you to design a metal graphic overlay for a control box. After designing the overlay, you could order the overlays from them. I can't seem to find the website. Anyone remember that?

Look at www.holtek.com and www.holmate.com You develop on an HT-ICE and they have OTP or they will do a mask where your program is factory-programmed. There is an up-front charge for this. This can get your huge quantities down to .50 a chip or less.