Search found 442 matches

by Engineer1138
Wed Jun 30, 2010 11:38 am
Forum: General Discussion
Topic: audio preamp design questions
Replies: 10
Views: 1593

Re: audio preamp design questions

I wouldn't use an LM368: its distortion specs aren't very good and it is designed to drive speakers, not for line drive. There are a lot of cheap op amps that perform much better.
by Engineer1138
Mon Jun 28, 2010 11:48 am
Forum: General Discussion
Topic: Temperature reader from different rooms.
Replies: 9
Views: 1780

Re: Temperature reader from different rooms.

Are you still interested in this? I built a Bluetooth wireless temperature monitoring system that reads a single sensor and reports data to a PC. I don't know if I will have the time to make it a commercial product (the person who wanted it went out of business!!), but I have a few PC boards made up...
by Engineer1138
Mon Dec 28, 2009 10:33 am
Forum: General Discussion
Topic: Source for Telephone DTMF type Chips ???
Replies: 5
Views: 1126

Re: Source for Telephone DTMF type Chips ???

Are you still looking? I may have a few SSI202 DTMF decoders if you're willing to pay a few bucks for shipping.

PM me and I'll check my storage area.
by Engineer1138
Fri Dec 04, 2009 12:54 pm
Forum: General Discussion
Topic: Servo wiring question
Replies: 11
Views: 2225

Re: Servo wiring question

It's probably a modified servo. I have (had?) a few servos that had the internal electronics disconnected and the rotation limiter removedso they were basically small gearmotors in R/C servo packages. Once that's done, it's trivial to wire up a DPDT switch to get direction control.
by Engineer1138
Fri Sep 25, 2009 12:33 pm
Forum: Up For Grabs
Topic: Wanted Midnight Engineering Magazines
Replies: 4
Views: 4012

Re: Wanted Midnight Engineering Magazines

Send me a PM so it shows up in my email. I rarely check this forum so I might forget. Actually I only have a handful from what I remember, so I may just give them to you.
johni wrote:Well what issues do you have?

Do you want to swap for other magazines/books or electronics?
by Engineer1138
Wed Sep 23, 2009 11:29 am
Forum: Up For Grabs
Topic: Wanted Midnight Engineering Magazines
Replies: 4
Views: 4012

Re: Wanted Midnight Engineering Magazines

I may have a few left. Do you have anything you want to swap for them? I really don't want money.
johni wrote:Looking for Midnight Engineering Magazines 1993 to 1998

Thanks,

John
by Engineer1138
Fri Sep 18, 2009 9:39 am
Forum: General Discussion
Topic: Emulate a Keyboard with a Notebook PC?
Replies: 5
Views: 1230

Re: Emulate a Keyboard with a Notebook PC?

We have the same problem here. The only solution I know of is to get a small LCD monitor and a mini keyboard so at least the parts are easy to carry. The problem is that when you're in the BIOS, the operating system isn't running, so the services available are too basic for things like Remote Deskto...
by Engineer1138
Wed Sep 09, 2009 8:59 am
Forum: General Discussion
Topic: flashing LED's
Replies: 12
Views: 2080

Re: flashing LED's

If you use the flashing LED to flash the others, an LM340 + 100 ohm resistor makes a very good 12mA current regulator for LEDs.
by Engineer1138
Mon Aug 24, 2009 10:15 am
Forum: General Discussion
Topic: Need help on a new project
Replies: 10
Views: 1651

Re: Need help on a new project

If your Shepherd is anything like mine, he can pull a lot harder than 30 lbs. A good guess would be 100lbs for short periods and over 150 for quick bursts. Anyway, it looks like what you need should be pretty easy to build if it doesn't need calibration. kheston's idea is a good one. A rod running i...
by Engineer1138
Mon Jul 27, 2009 7:39 am
Forum: General Discussion
Topic: Portable spreadsheet scorecard
Replies: 4
Views: 1070

Re: Portable spreadsheet scorecard

I built something like this about 15 years ago for judging animal competitions so I had some idea of the effort involved. Back then it was custom designed keypads with serial connections to a base unit. Honestly, if I were to do the same thing again, I'd either go the cheap netbook route or program ...
by Engineer1138
Sun Jul 26, 2009 9:51 am
Forum: General Discussion
Topic: Portable spreadsheet scorecard
Replies: 4
Views: 1070

Re: Portable spreadsheet scorecard

$50 in parts cost each? You might just barely make it. Once you factor in the development time, though, it becomes much cheaper to just buy a bunch of $300 netbook PCs! If you can get the system you mention done in less than 80 hours, my hat's off to you. That 80 hours at the low end of the cost of ...
by Engineer1138
Wed Jul 22, 2009 9:45 am
Forum: General Discussion
Topic: How do you identify different types of screw heads
Replies: 22
Views: 3296

Re: How do you identify different types of screw heads

Brute force approach if patience fails: Hand drill + screw remover bit! Actually, if you really want to go brute force, forget the screw remover and just drill the entire screw out of the casting. Ah, the memories of last weekend spent under my truck with an angle grinder and a cutoff wheel and face...
by Engineer1138
Wed Jul 22, 2009 9:41 am
Forum: General Discussion
Topic: Front-panel laser-printed plastic film. advice pls
Replies: 7
Views: 1504

Re: Front-panel laser-printed plastic film. advice pls

I have used Avery matte finish clear laser label stock from Office Depot. But I think that if I were making 100+ of something, I'd go to a small print shop and see how much they charge to print on polycarbonate (Lexan) film. Lexan will hold up much better and printer ink looks better than toner. Alt...
by Engineer1138
Wed Jul 22, 2009 9:37 am
Forum: General Discussion
Topic: Deal Extreme, or "Extremely Slow Deals" ?
Replies: 28
Views: 3566

Re: Deal Extreme, or "Extremely Slow Deals" ?

gerty: I have never received any kind of email from Deal Extreme except to say that my order was received/shipped. Are you sure you didn't click some "add to email" link? MrAl: The second order was for some 1W white LEDs and optics and something else I don't remember. Can't remember what the first o...
by Engineer1138
Tue Jul 21, 2009 4:56 pm
Forum: General Discussion
Topic: Deal Extreme, or "Extremely Slow Deals" ?
Replies: 28
Views: 3566

Re: Deal Extreme, or "Extremely Slow Deals" ?

I'm on my third order from DE. The first came in about a week, the second about three weeks. It's only been about 3 days this time, so we'll see :-)