Unusual functions of cheap parts
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From: Henry Kiefer on 24 Nov 2005 03:40 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
From: Stefan Heimers on 24 Nov 2005 08:07 Henry Kiefer wrote: > > Do you know of other interesting devices or circuits good for misuse? I never tried it myself, but I heard that some people abused opened memory chips as cameras, back when CCD camera chips were too expensive for hobbyists. http://www.classiccmp.org/pipermail/cctalk/2004-May/042581.html http://groups.google.com/group/comp.robotics.misc/browse_thread/thread/652cc4b0e1ccee57/f84b0f2d5c0b6da7?lnk=st&q=opened+RAM+chips+used+as+camera&rnum=6#f84b0f2d5c0b6da7
From: R.Freitag on 24 Nov 2005 13:00 Henry Kiefer wrote: [...] > Do you know of other interesting devices or circuits good for misuse? Take away the hat of a 2N3055 and use it as a light sensor (sensitive). Robert > > Best regards - > Henry -- 'Vom Standpunkt eines Beamtenrechtlers aus betrachtet ist der Tod die sch?rfstwirkenste aller bekannten, langfristig wirkenden Formen der vollst?ndigen Dienstunf?higkeit.' aus: Kommentar zum Beamtenrecht.
From: Jorgen Lund-Nielsen on 24 Nov 2005 12:30 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. Jorgen
From: John Larkin on 24 Nov 2005 13:04
On Thu, 24 Nov 2005 09:40:27 +0100, "Henry Kiefer" <otc_friend(a)gmx.net> 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 > A 1N4007 can also be used as a drift step-recovery diode and as a plasma avalanche diode. Together, two can generate a kilovolt edge with a 100 ps risetime. GAASfets make good fast analog switches; they behave pretty much like jfets. Wide-open LDO regulators make nice resettable fuses. Ferrite beads do all sorts of interesting stuff. Power mosfets make good heaters, and TO-220 bipolar transistors make nice temperature sensors. LVDS line receivers are surprisingly good comparators, and *fast* I could go on... John |