Based on the principle of tester, i want 2 design a alarm such that when we touch any metal surface alarm should ring

 

Use a search engine to look for "cmos touch switch" and find circuits like this one - http://freecircuitdiagram.com/2008/08/11/very-simple-touch-switch-using-4050-cmos-buffer/

 

Check out the Picaxe 18M2 microprocessor. It has a touch input or 2. This would make this project very simple. Look at the picaxe website and join the forum. They are a really knowledgable and friendly bunch.

 

I'll never figure out why this younger crowd loves to complicate things by using microprocessors when so many much simpler to construct circuits still exist.

 

I'll never figure out why this younger crowd loves to complicate things by using microprocessors when so many much simpler to construct circuits still exist.

They're just using current technology! Remember, vacuum tubes still exist.

I can make an 8-pin PICAXE with 256 instructions, dance circles around a one, or dozen, 14-pin logic chips...and I'm no programmer. I'm 65 (well, I will be tomorrow), and love simple, basic electronic circuits. But to get that much control in that small a package...wow!

The thing I think they do miss though, is the understanding of basic components...whether discrete, or hidden in an epoxy block.

One could say the same about circuit simulators. I would say they're missing out on the magic smoke experience.


Ken

 

I'll never figure out why this younger crowd loves to complicate things by using microprocessors when so many much simpler to construct circuits still exist.

I'm flattered! Thanks for putting me in the"younger crowd", I'm 63. Now if I could get my teen aged grandaughter to agree with you I'd be all set.

I don't see how microprocessors complicate things, especially with the Picaxe system which can be made as simple as you like or as complicated as you like. 7th graders are using them.

 

They're just using current technology! Remember, vacuum tubes still exist.

I can make an 8-pin PICAXE with 256 instructions, dance circles around a one, or dozen, 14-pin logic chips...and I'm no programmer. I'm 65 (well, I will be tomorrow), and love simple, basic electronic circuits. But to get that much control in that small a package...wow!

The thing I think they do miss though, is the understanding of basic components...whether discrete, or hidden in an epoxy block.

One could say the same about circuit simulators. I would say they're missing out on the magic smoke experience.


Ken

I don't know, I'm still all in favor of not complicating matters by having to write code, probably because it takes me time to do so and I'm not too good at it. One of these days I'll probably encounter a situation where an embedded microcontroller would be preferrable, just haven't yet.

Also goes back to the fact most kids in school can't add two 2 digit numbers in their head - much less multiply them - without a calculator.

Clerks at McDonalds can't make change unless they can key in the A/T button.

"$1.42 please" then you plop 0.17 on the counter after they've entered the $2 you gave them seconds earlier and you've lost them.

 

I don't know, I'm still all in favor of not complicating matters by having to write code, probably because it takes me time to do so and I'm not too good at it. One of these days I'll probably encounter a situation where an embedded microcontroller would be preferrable, just haven't yet.

Also goes back to the fact most kids in school can't add two 2 digit numbers in their head - much less multiply them - without a calculator.

Clerks at McDonalds can't make change unless they can key in the A/T button.

"$1.42 please" then you plop 0.17 on the counter after they've entered the $2 you gave them seconds earlier and you've lost them.

Ummm.... Square root of.......carry the 6.....divide by sin(c*f)..

75 CENTS!! YOUR CHANGE WOULD BE 75 CENTS!

HA! I didnt even need a calculator!

Sorry I went off topic for a sec... What were we talking about? OH YEAH, complicating things.

I think coding and using uCs are a very cost effective and board space friendly way of doing things these days.

It also makes upgrades that much easier.

As for you old farts, HAPPY BIRTHDAY KMoffett !

 

Don't even use the word "square root" around them, they'd probably misinterpret it.

Kind of like today, I've been finishing up the PC layout for a very low noise, high gain RF preamp I'm building. Although I could have made it with through hole components, common sense was to make the preamp section with SMD parts. I don't so much mind laying them out, just don't like solderng them. I would probably have been just as happy if I could get the same specs using a 6CW4 Nuvistor vacuum tube since they'll also operate up to the GHz range.