Is Electronics Addictive?

What did the science fair project do?

Lit his joint ;-) ...Jim Thompson

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Hmm... two-transistor multivibrator going to a step-up transformer? :-)

Although if he "upped the output" with the second one, maybe a single-transistor oscillator followed by a power amp... :-)

Not necessary. You do need to pick a direction and try to stay focused. One of my many paths has been with PIC microprocessors and especially with the miKroelectronica Developer boards and their Pascal Compiler.

The current project is to move up to the Third prototype level for my Amateur Radio Antenna rotator. The control box took a lightning hit & the vendor was not interested in anything other than sell a whole new system.

The next level will include computer control as well as manual and perhaps IR as well. You can buy modules or build them. Surface mount is an option but you can go a long way on DIP's and prototype boards.

Walmart has some $10 electric screwdrivers intended for 4-AA batteries that I want implement on the next project. Lots of fun DIY stuff that is just waiting. How about a crawler robot that will spray paint the Carport roof over my Motor Home?

If you just like to read about others activities there is a wealth of info on the web.

PS: I forgot about the remote auto tuner (Ham Radio) that is to go out into the garden shed and handle a KW+!

John Ferrell W8CCW

I did that in Jr. high school. With a pair of TO-3 Germanium transistors (DS503), and a vibrator transformer from a '50s car radio. You could light a 15 W 120 V light bulb with it. :)

Yay! Doorknobs ;-) ...Jim Thompson

Neat... and you could probably get some unsuspecting kids to touch the high-voltage output as well... "nah, go ahead and touch it, it's just battery powered!" :-)

snipped-for-privacy@att.bizzzzzzzzzzzz expounded in news: snipped-for-privacy@4ax.com:

"Silent keys".

Warren

I used to take a wire and drag it lightly over the posts of a car battery, throwing sparks. Then ask the kiddies to touch the posts. They'd back away, then I'd grab a post in each hand... and they were duly impressed ;-) ...Jim Thompson

John Ferrell expounded in news: snipped-for-privacy@4ax.com:

I was hooked around 8-10 when my father brought home a couple of dry cells, a piece of wire and a light bulb. Once I knew how to make that bulb light, I was hooked. I would take parts out of wrecked cars etc, including flashers and gas gages etc. and make them all work. I eventually got a model-T Ford coil to play with as well (many hours of fun).

Later my hobby involved dragging home old B&W TV sets that folks put at the end of their driveway. Thinking about it now, its a wonder my mother put up with that.

I was all set for a career in electronics until I met up with the IBM-1130 in high school. Career wise, programming was a good move for me. My bro-in-law went into electronics but now manages maintenance at IBM, rather doing it (nothing but board swapping occurs here).

So while I went into a career of programming, the interest in electronics lingered. It suffered some dark times when I first got married ("what do ya need all that junk for?").

In '87 I got my ham license (quit smoking while saving up for that first Drake transceiver). Did that for a few years, but not active now (too many other distractions). But I do keep my hand in it.

Lately with the AVR platform and a resurgence of interest in analog semiconductor electronics, I am finding new excuses to build and design things.

My main focus now is to learn the _engineering_ aspects of the field. All of that seemed unavailable to me in my youth (no internet, no advice on books, no mentors etc). I did however subscribe to pop Electronics etc.

The combination of great texts, simulations on the PC (LTspice) and acquisitions of some half decent hobby level equipment along the way (eBay and hamfests) is making the hobby increasingly fun. I am also increasingly getting more "what do ya need _that_ for?" ;-)

To me the best fun is designing something from scratch and making it work. It's not nearly as fun to build someone else's worked out design. Though building with your own mods is sometimes a good compromise.

I tried to interest my son in electronics but young people today just look at computers and electronics as "too much to learn". The only time he shows interest is when he needs his guitar / effect / amp / cable fixed. I have managed to get him to solder his own cables on a couple of occasions. He has a mild interest, but not the drive to learn more about it.

My bro-in-law (above) pretty much did, though I'm not sure how much of a hobby it was for him. His father OTOH, remained in the hobby it until he passed, AFAIK.

Warren

No. You're thinking of the DS503/2N441 in the TO-36 package.

Hmmmm? DS501's were in the round package with a stud for the collector, pins for emitter and base, plus an insulated locating pin to keep it from rotating while tightening the stud nut.

As in

I always called them door knobs.

In 1957 my father-in-law-to-be machined an aluminum block heat sink for my class-A car amplifier ;-) ...Jim Thompson

It received AM broadcast band signals and playet them through a speaker that had been scrounged from some old radio or something.

I think the thing that won me the ribbon was that the original kit came with just the one transistor, and I figured out how to cascade another so it could actually drive the speaker and didn't need the 2K ohm headphones. :-)

Cheers! Rich

FWIW, it was a single-transistor AM BCB receiver followed by a power amp.

At the time, I didn't really know that much about it - I had heard about cascading transistors, and at first I just took out the headphones and put another common-emitter transistor with its base connected to the collector of the detector transistor and its collector to the speaker output transformer which was in turn connected to the 3V Vcc. It didn't do anything until I realized that there was no current source for the collector of the detector than, which went to the base of the power amp, so I took about a 100K resistor and ran it right from its own collector to the junction of its base and the collector of the detector.

Looking back, that was a horrendous amount of negative feedback, but it might have actually done some linearizing. If I had to do it again, I'd just go right to Vcc, and added a resistor from base to ground, to prevent thermal runaway.

Cheers! Rich

The following year, some kid won with a fish attractor - basically a Hartley oscillator audio osc and a MVB to make it go "beep, beep, beep, etc." It was suspended off the edge of the boat and submerged; the story was that the fish come to investigate where the noise is coming from.

Cheers! Rich

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Yes. It was a typo. I didn't catch it, because I had used DS503 for the project like it states above..

The Delco car radios wit DS501 or DS503 outputs were a single ended, temperature sensitive jokes.

OK, so what's the "harmful" part of an interest in electronics?

Thanks, Rich

wrote in

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Not mine. I was not nicknamed "VBE Thompson" for nothing... I was the expert at stable bias. ...Jim Thompson

Electronics is fine. I was referring to your bit above.

John