Unusual functions of cheap parts
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From: RST Engineering on 25 Nov 2005 12:20 And by varying the reverse bias through a current source (or moderately large fixed resistor) you can make them into nifty phase shifters. Jim > I wrote: NOT PIN - Diodes - as they wouldn't snap. > > i mean Band Switching diodes for TV-Tuners like the BA244 and the BA682. > > BA682 Datasheet: > > http://www.vishay.com/docs/85530/85530.pdf > > - and they snap! Try it! > > Jorgen > dj0ud > >
From: Frithiof Andreas Jensen on 25 Nov 2005 12:55 "Henry Kiefer" <otc_friend(a)gmx.net> skrev i en meddelelse news:4385b3b1$1$27887$9b4e6d93(a)newsread4.arcor-online.net... > Do you know of other interesting devices or circuits good for misuse? Unbuffered logic gates can make a really bad but still useful analogue amplifier by adding feedback and bias.
From: John Larkin on 25 Nov 2005 13:04 On Fri, 25 Nov 2005 12:46:17 +0100, Jorgen Lund-Nielsen <jorgen.lund-nielsen(a)xxxxxxxxxxxxdesy.de> wrote: >John Larkin wrote: >> On Thu, 24 Nov 2005 18:30:06 +0100, Jorgen Lund-Nielsen >> <jorgen.lund-nielsen(a)xxxxxxxxxxxxdesy.de> wrote: >> >> >>>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 >>> >>>Tuner Switching Diodes like the european BA244 (NOT PIN-Diodes!) work >>>well as medium fast Step Recovery Diodes. >>> >> >> >> Tell me about it. I tried some pins to see if they would snap, and >> they turn out to have incredibly mushy reverse recovery, Slop Recovery >> Diodes. >> >> I'll have to try the varicaps. >> >> John > >Hello John, > >I wrote: NOT PIN - Diodes - as they wouldn't snap. > I got that! >i mean Band Switching diodes for TV-Tuners like the BA244 and the BA682. > >BA682 Datasheet: > >http://www.vishay.com/docs/85530/85530.pdf > >- and they snap! Try it! OK, I'll try some. Thanks John
From: John Larkin on 25 Nov 2005 13:05 On Fri, 25 Nov 2005 09:07:38 +0000, Pooh Bear <rabbitsfriendsandrelations(a)hotmail.com> wrote: > > >John Larkin wrote: > >> TO-220 bipolar transistors make nice temperature sensors. > >I like that trick. Esp the isolated tab type. > >Graham There's also an LM35 in a TO-220 package! Ideal way to monitor a heatsink. John
From: Paul Keinanen on 25 Nov 2005 13:18
On Thu, 24 Nov 2005 18:49:24 -0500, Jon Yaeger <jono_1(a)bellsouth.net> 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). The problem is that the carbon rod conducts heat quite well, so after a while, any wooden object will catch fire :-). >Tap the free ends of the rods together. Move them apart as necessary. You must have quite slow fuses in 110 V land if you can do a reliable ignition without blowing the fuse. For 230 V operation, I would suggest using a current limiting resistor (such as a large heater) or an inductance (such as fluorescent light ballast) during the ignition. When there is a solid arc, the current limiter can be shorted out. Paul |