HISTORY:
Sustainability is the name of the game! Anything (that has been tested and still functioning properly) should be repurposed creating saving in wasted Ee and reducing the poisoning our environment when items are buried in the earth at the local tip needlessly.
Never heard of Ee? It is a concept that creates a measurement of ALL things (not just electronics) that humans have made and the energy used in obtaining the raw material, processing the materials right through to a finished product and even should include the shipping of the item to the distributors/retailers.
If you would like to know more about Ee values, please take a look HERE
Ex workshop spare parts and small manufacturing stock
ALL devices have been sourced through reputable local distributors such as RS Electronics, Farnell, WES and Rockby (Victoria) NOT direct import Chinese (often dodgy spec) devices
The beauty of this trimmer is that it is of high quality, precision manufactured and in SEALED units. Perfect where you wish to make extremely fine adjustments to circuit parameters.
Very fine adjustment of the resistance at the wiper from either end of the track is possible because this is a 25 turn trimmer
Of course you will need to make sure the pin spacing suits the PCB you are working on and I have provided physical measurements of this component below.
ALLEN BRADLEY - Trimpot
GENUINE A.B PRODUCT
Made in England
Model: Not sure!
I do have reference catalogues for these old passives from A.B but this trim pot is not mentioned (1980's catalogue) and I am pretty sure these were purchased later, in the late 1990's ~ early 2000's
Body colour: Light Grey
ID MARKINGS ON THE BODY:
Side:
85 05
85W 20R M
Stamped into the body on another side:
A.B logo
UK
(Schematic of the pot/pin connections)
CW
Track resistance: 20 Ohm
Taper: Linear
Multi-turn: 25
Slot screw head adjustment from above
Clockwise
Power rating: 500mW
Mounting: Vertical PCB
DIMENSIONS:
10mm wide x 10mm height x 5mm deep
5.75mm PCB pins (tinned)
2mm pin spacing
COSMETIC CONDITION:
NEW Old Stock (in original packaging)
NO body damage
NO pin damage (straight)
TEST NOTES:
I measured a few of these trim pots to establish exactly what their characteristics are (part number was of no help to me)
Definitely 25 turn, once the 'end of travel' is reached, physical resistance to further turning is met by a "click click click" as the slot head is rotated. The resistance does not change, either highest or lowest value, depending upon which way the screw was rotated.
Tracks that I measured ranged between 20.8 Ohm and 21.2 Ohm so it would appear these are at least 10% tolerance
Movement of the wiper(s) across the track was smooth and even, corresponding resistance change was the same.
Extremely fine adjustments are possible with these trim pots as each turn of the screw through 360 degrees only changes the resistance by 0.8 Ohms!
I suspect these use a plastic conductive/cermet track for high accuracy and reliablity.
