Search found 93 matches

by ljbeng
Tue Apr 24, 2007 7:37 am
Forum: General Discussion
Topic: Fooseball goal sensor
Replies: 9
Views: 2808

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...
by ljbeng
Tue Apr 24, 2007 7:27 am
Forum: General Discussion
Topic: Op Amp Circuit Help
Replies: 6
Views: 2441

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....
by ljbeng
Tue Apr 03, 2007 11:39 am
Forum: General Discussion
Topic: Op Amp Circuit Help
Replies: 6
Views: 2441

Op Amp Circuit Help

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...
by ljbeng
Thu Feb 22, 2007 11:42 am
Forum: General Discussion
Topic: Accurate Frequency generation
Replies: 6
Views: 2292

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.
by ljbeng
Wed Feb 21, 2007 2:17 pm
Forum: General Discussion
Topic: Accurate Frequency generation
Replies: 6
Views: 2292

Accurate Frequency generation

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...
by ljbeng
Thu Jan 25, 2007 7:27 am
Forum: General Discussion
Topic: Need to control 16 digital outputs based on 16 analog inputs
Replies: 10
Views: 3886

Forgot the software...

PC-DSOFT5 $395
by ljbeng
Thu Jan 25, 2007 7:13 am
Forum: General Discussion
Topic: Need to control 16 digital outputs based on 16 analog inputs
Replies: 10
Views: 3886

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...
by ljbeng
Thu Jan 04, 2007 11:35 am
Forum: General Discussion
Topic: Test for Nickel
Replies: 5
Views: 2305

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.
by ljbeng
Wed Jan 03, 2007 6:16 am
Forum: General Discussion
Topic: Test for Nickel
Replies: 5
Views: 2305

Test for Nickel

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.
by ljbeng
Wed Nov 01, 2006 1:20 pm
Forum: Up For Grabs
Topic: Smart Block
Replies: 1
Views: 2321

Smart Block

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???
by ljbeng
Mon Oct 30, 2006 2:25 pm
Forum: General Discussion
Topic: Daylight Saving
Replies: 19
Views: 6051

Daylight Saving

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...
by ljbeng
Mon Oct 02, 2006 3:00 pm
Forum: General Discussion
Topic: EL Backlight
Replies: 0
Views: 1069

EL Backlight

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...
by ljbeng
Wed Aug 16, 2006 8:09 am
Forum: General Discussion
Topic: Overlay design software
Replies: 2
Views: 1371

Thanks, Front Panel was it. I must have tried a hundred searches on Google but I kept getting cellphone overlay junk....
by ljbeng
Tue Aug 15, 2006 2:27 pm
Forum: General Discussion
Topic: Overlay design software
Replies: 2
Views: 1371

Overlay design software

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?
by ljbeng
Mon Feb 27, 2006 11:33 am
Forum: General Discussion
Topic: lowest cost mcu and how to mass produce
Replies: 13
Views: 3444

Re: lowest cost mcu and how to mass produce

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.