Unusual functions of cheap parts
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From: Jon Yaeger on 24 Nov 2005 18:49 Take apart a couple of D cell carbon-zinc batteries. Wash off the carbon rods. Put each in a wooden clothes pin and connect the attached ends to the mains voltage (US customers only, please). Tap the free ends of the rods together. Move them apart as necessary. Very bright! Much brighter than you are. Jon
From: ehsjr on 24 Nov 2005 19:40 Henry Kiefer wrote: > Hi all - > > After my first thread going from "standard" cheap parts for up to vhf > frequency to a discussion about the usefulness of Spice simulator...... I > try it another time hopefully get attention of frustrated co-readers: > > For example the rechtifier diode 1N4007 can be used as a rf switching diode, > for example as rx/tx-switch. This is because it is a pin structure diode. > This type is cheap and you can get it almost everywhere. It shows good > performance for the price. Surely for high-end you should do it with another > type tuned to the application it is made for. But anyway it works in some > circuits. > > Do you know of other interesting devices or circuits good for misuse? > > Best regards - > Henry > > An LED as a shunt regulator. Also, as a varicap. Ed
From: Bob Monsen on 25 Nov 2005 03:43 On Thu, 24 Nov 2005 18:49:24 -0500, Jon Yaeger wrote: > Take apart a couple of D cell carbon-zinc batteries. > > Wash off the carbon rods. Put each in a wooden clothes pin and connect the > attached ends to the mains voltage (US customers only, please). > > Tap the free ends of the rods together. Move them apart as necessary. Very > bright! Much brighter than you are. One of the MIT EE course videos on the web shows a demonstration of AC across a pickle... it is an interesting effect. Not sure how the pickle tastes afterward. Cooking hotdogs with AC is similar, but the pickle gives off a much nicer translucent flickering glow. Very pretty. --- Regards, Bob Monsen The question of the ultimate foundations and the ultimate meaning of mathematics remains open; we do not know in what direction it will find its final solution or even whether a final objective answer can be expected at all. "Mathematizing" may well be a creative activity of man, like language or music, of primary originality, whose historical decisions defy complete objective rationalization. - Hermann Weyl in 1944
From: Pooh Bear on 25 Nov 2005 04:07 John Larkin wrote: > TO-220 bipolar transistors make nice temperature sensors. I like that trick. Esp the isolated tab type. Graham
From: Frithiof Andreas Jensen on 25 Nov 2005 04:52
"Henry Kiefer" <otc_friend(a)gmx.net> wrote in message news:4385b3b1$1$27887$9b4e6d93(a)newsread4.arcor-online.net... > Do you know of other interesting devices or circuits good for misuse? LED's work both ways, as a light emitter and a photodiode. The inbuilt colour filter can be used to distinguish between Grass and Not grass f.ex. by comparing output from a red and a green LED using white light as illumination. Back when fiber was ex$$$pensive one often saw clever circuitry using two transmitters to form a duplex connection over a single fiber. The USD 10 solar powered garden lamps will, with a little persuation, yield a nice solar cell well below the price of a similar unit in the shops - and - two 600 mAh NiMh batteries and a grotty circuit for switching the LED. |