max-man said:
I need to get hold of a 1.5K trimmer pot for an old arcade game
monitor but cannot find one of this value anywhere. Seeing as it's
essential that I use 1.5K but the closest that I can find is 1K or
2.5K, is there any way that I could modify, for example, a 1K pot with
a 0.5K resistor to give the correct value, or won't that work seeing
as it would be external to the pot and wiper?
Hi, Max. I kind of wish you'd have given some more information on the
circuit, and how your trimmer is being used.
Anyway, there are a number of things you can do. First, 2K is actually
very common for trimmers -- check the Digi-Key catalog. Since many
pots are rated at +/-20%, the high end of the tolerance might be close
enough. You might want to try it.
Another thing you can do if it's being used as a voltage divider is to
put a 5.6K 5% resistor across the legs of the pot. The total
leg-to-leg resistance will then be almost 1.5K, and the wiper will
scroll across the right voltage range.
.-----o
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5.6K | | | |<--
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'-' '-'2K
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created by Andy´s ASCII-Circuit v1.24.140803 Beta
www.tech-chat.de
If you don't need the top 1/3 of the range, you might want to put a 510
ohm resistor in series with a 1K pot. This would have some value for
some applications.
o
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.-.
510| |
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'-'
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1K| |<--
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'-'
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o
created by Andy´s ASCII-Circuit v1.24.140803 Beta
www.tech-chat.de
If you absolutely, positively have to have exactly 1.5K, and nothing
else will do, you might want to contact some manufacturers' reps, and
ask for a couple of samples. You'd be amazed at what a well-placed
request from a one-man engineering firm needing a sample for a
potentially good volume prototype can do.
Good luck
Chris
