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#1 2006-07-05 00:19:23

importeur1
Guest

KNOBS AND PADDLES - TRIM POTS for KNOBS

If only i were smarter!!

I cracked open some paddles.. i have 2 pairs.

I made a third pair with 500k resistors, both of which have a dead zone which i
attributed to the 470k thing (which i read somwhere)

are you ready for it?

Old commodore paddles have a 200k resistor with a capacitor attached.. new
paddles have 500k resistors...

and 470 still works best for my homebrew paddles (which i have rigged with some
new parallel 3.8M resitors (close enough)

so...

there you have my tiny contribution to the world

__________________________________________________________

SO, after using 500K resistors i realized that that large null area in the
rotation that had no effect was the 30k that the commodore doesn't recognize.

Despite lots of info to the contrary, they don't use 500K, they use 470K.

HOwever, when i went to buy 470K pots, i found them only in giant bulky form and
costing 3 dollars (They were rated to something like 100 Amps or some ungodly
current)

Anyhow.. i was despondant until i resurrected the knowledge from within, much
like Inhumanoids, that 80s cartoon.. only instead of evil wtihin, it was
knowledge..

EVIL KNOWLEDGE

1 / ( 1 / 500 + 1 / X ) = 470!

so,

1 = 470 ( 1/ 500 + 1/x)
1 / 470 = 1/500 + 1/x
1/470 - 1/500 = 1/x
x(1/470 - 1/500) = 1
x = 1/(1/470 - 1/500)
or x = 7833 and a third.

get two 3.9M resistors or 1 7.8M resistor (if you can find it) or any
combination os 3c resistors that adds up to 7.8M

wire them in series

THEN, wire that series in parallel with the trim pot

here is my shitty MS paint diagram of it.

now, you'll have more accurate response from your knobs on your new commodore
P64 machines.

or of course you can just buy original paddles...

sad

__________________________________________________________
originally posted by

David Dineen-Porter

 

#2 2011-01-30 09:49:18

musicrollercoaster
Bloody beginner
Registered: 2011-01-24
Posts: 1

Re: KNOBS AND PADDLES - TRIM POTS for KNOBS

is there any chance you post the <mspaint schematics>?
I might give it a try smile

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