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Vydáno dne 16. 02. 2012 (305 přečtení)

a zkušební desky: ale text v angličtině (ovšem jednoduché takže to snad pochopíte)

Novy1 All,

While working on something unrelated, I stumbled onto a test for protoboard
noise arising from contact resistance variations. It amounts to a Wheatstone
bridge with a 0.5 or 1-mA meter in series with resistance measuring the balance.

I used a 9-volt battery and 330 above 680 ohms in each side. Those values
should not be important. They're just what I had in the board when I noticed
reading jumps indicated contact noise. I had 100 ohms in series with the meter.
100 ohms in series with a 2,000-ohm potentiometer should work better.

Excepting the battery, set up the circuit on the breadboard. Set the 2,000
potentiometer to full resistance. Connect the 9-volt battery, Slowly reduce
the potentiometer resistance until the meter reads perhaps 25% full scale. If
the meter reading shifts during the next two minutes, the breadboard contacts
uses exhibit extreme noise. If the meter holds steady until tapping the
workbench, that's better. If the meter still holds steady until wiggling the
resistors, better yet. If the reading holds steady even when wiggling the
resistors, that's probably exceptional.

Happy experimenting,

Steven

( Celý článek | Autor: Krysatec | Počet komentářů: 6 | Přidat komentář |

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