trimmer pot with a knob

[smp1990]

Im working on a mod similiar to Mamu's "Tiny" and i was just wondering if any one knows where to get a 200 ohm trimmer pot with a knob like hers. It does not have to be the same exact type, but just 200 ohm with something more than a flat adjuster. Ive checked the normal sites (digikey, onlinecomponents, etc) but only seeing flat ones or ones that are not 200 ohm. Any help is greatly appreciated.

 

[slimest]

I don't know what kind of resistor you need, but there is a lot of them on Digikey. Choose Potentiometers, then choose needed type (say, rotary) and filter by criteria "200 ohm"

 

[smp1990]

I don't know what kind of resistor you need, but there is a lot of them on Digikey. Choose Potentiometers, then choose needed type (say, rotary) and filter by criteria "200 ohm"

i did exactly that already but i could not find one with protruding knob.

 

[asdaq]

I'm pretty sure she buys the pots and knobs separately and glues a post onto the pot screw to attach the knob to.

 

[been there]

try this PLASTIC SHAFT FOR PIHER POTENTIOMETER, 5372 | AllElectronics.com

 

[TomCatt]

try this PLASTIC SHAFT FOR PIHER POTENTIOMETER, 5372 | AllElectronics.com

EXCELLENT!!! Been looking for something like this!

Hmmm ... anyone order any of these, I'll pay ya $2 for 10 of 'em

 

[smp1990]

try this PLASTIC SHAFT FOR PIHER POTENTIOMETER, 5372 | AllElectronics.com

not exactly sure how it attaches but only one way to find out lol. im just going to glue a knob on them from now on

 

[smp1990]

Asked mamu directly and found what i was looking for

Electronic Depot, Inc. - Wholesale Distributor Of Industrial Electronic Components

 

[asdaq]

Good idea. I believe here's a link with a pic of it:

NTE Electronics NTE 500-0099-PK 63P-T607-201 TRIM 200 OHM<br><a href="http://www.arcade-electronics.com/nte_electronics.aspx">NTE Electronics Selection Page</a> - 63P T3 Style series (NTE 500 series) - Packaged - Arcade-Electronics.Com - Detail

That plastic shaft part snaps into something unique and I couldn't find any Piher pot....

 

[breaktru]

Good idea. I believe here's a link with a pic of it:

NTE Electronics NTE 500-0099-PK 63P-T607-201 TRIM 200 OHM<br><a onclick="_gaq.push(['_trackEvent', 'Outgoing', 'www.arcade-electronics.com', '/nte_electronics.aspx']);" href="http://www.arcade-electronics.com/nte_electronics.aspx">NTE Electronics Selection Page</a> - 63P T3 Style series (NTE 500 series) - Packaged - Arcade-Electronics.Com - Detail

That plastic shaft part snaps into something unique and I couldn't find any Piher pot....

That's the exact pot I used in my microcontroller mod.
I'd like to point out that it is a good pot but the legs are fragile and snap off easily. Support legs with epoxy for strength.
I also epoxied the knob on to the pot as shown............

 

[meatsneakers]

Has anyone used a large value pot with a resistor in parallel? I found these pots: Digi-Key Part Search which look perfect.

They're cheap and they're small, but don't come in a 200 or even 500 ohm value so they're too course to use with an OKR module. Putting a 330 in parallel would bring the pot into a usable range of 250 ohms but I don't know how the granularity of the pot will be effected i.e. will most of the resistance occur in only a few degrees of its rotation?

 

[WillyB]

Has anyone used a large value pot with a resistor in parallel?

They're cheap and they're small, but don't come in a 200 or even 500 ohm value so they're too course to use with an OKR module. Putting a 330 in parallel would bring the pot into a usable range of 250 ohms but I don't know how the granularity of the pot will be effected i.e. will most of the resistance occur in only a few degrees of its rotation?

On another forum we discussed this last year, the modder put some actual numbers together, I assume they are correct (he does lovely work BTW). He had bought 100k pot by mistake.

That's a great idea, parallel resistance always yields some interesting results.
I remember seeing someone with a push button selector that cycled through 4 different resistors that got him quite a few different resistances by changing the combination of resistors used.

Unfortunately doing this with a pot yields some even weirder results. While it would be a quick fix, it would render most of the pot pretty much useless.

If I did that with a 200 ohm resistor, I would be left with a 200 ohm pot, which is kinda what I wanted anyways but they weren't available.

100,000|200= 199.6 ohm
50,000|200= 199.2
25,000|200= 198.4
12,500|200= 196.8
6,000|200= 193.5
3,000|200= 187.5
1,000|200= 166.6 (Now is when we start seeing it ramp down quickly)
500|200= 142.8
250|200= 111.1
100|200= 66.667
50|200= 40.0
25|200= 22.2

Assuming I am looking at this correctly, the first 99% of the pot controls only 33 ohms. The remaining 167 ohms is controlled by the last 1%. With the OKR-T/6 High resistance = low voltage. So I'd be stuck in the lower range of the voltages, until the last little bit where I'd zoom up to my max voltage.

His analysis seems sound.

 

[meatsneakers]

Found another source: Multiturn Potentiometers Wit Knob and Potentiometer Ideal For Breadboarding - Cermet; 1/2W; Single Turn with Shaft

 

[mamu]

The POT with the knob was what I used on my first Tiny (renamed to Sprite) mod.

Here's what I'm using on my mods now. You have to buy all 3 parts - the POT, the shaft, and the knob - separately. The shaft snaps into and through the center hole of the POT - very secure. Then you can attach a knob to the shaft.

POT:
Trimmer Resistors - Through Hole 200ohms 10mm Rnd Side adj

5mm shaft for this POT (for knobs that accept a 5-6mm shaft):
JPEPL5012NE

3mm shaft for this POT (for knobs that accept a 3mm shaft):
SPIND01 - SPINDLE 3mm (BLACK)

thumbwheel for this POT:
WIEL/PT10 - WHEEL FOR S-SERIES TRIMMER