Help identify this encoder - Page 1
Forum section: electronics / repair

author: DrJoe
author_rank: Contributor
timestamp: May 25, 2018, 03:20:29 am
content: My 25 year old oven has an issue. The encoder pictured just above the tape measure has failed. Replacement control boards are not available. It is the dial that controls the clock and timer. It's not pot (I think) as it turns freely in both directions and has no stop. Is this a jelly-bean part that can be easily replaced? I don't know anything about encoders so any advice would be greatly appreciated. I'm getting tons of grief from "the one who must be kept happy" about her not being able to set the time... I say whatever, use your watch, but she thinks differently. I can send the board out for repair, but the down time would probably end my marriage. I would de-solder it and look for a part number, but my soldering stuff is at my weekday work sight, 2 hours away. I'm only home on the weekends. I will bring the soldering stuff home in two weeks when I'm back, but I'd like to have the part so I don't have desolder and resolder it to order the part only to go through the same procedure two weeks later. The board is a bear to get to, takes at least 30 min to get it it all disassembled, not counting the time to scrounge for replacement screws for the ones that bounce off to never-never land.Thanks guys.

author: helius
author_rank: Super Contributor
timestamp: May 25, 2018, 04:08:12 am
content: That's a rotary encoder from CTS corp.Does it have a built-in pushbutton? Part of the pins are hidden behind your measuring tape, which is actually quite important to find the exact part number.

author: DrJoe
author_rank: Contributor
timestamp: May 25, 2018, 04:42:25 am
content: It doesn't have a button, ie, push function, just rotation. Here's a pic without the tape. One soldered connections on each side, three on the bottom. Thanks so much for the help.

author: helius
author_rank: Super Contributor
timestamp: May 25, 2018, 05:06:34 am
content: Looks like CTS 288X series. Do you have a depth caliper to measure the height of the threaded bushing and the shaft?Look at this datasheet and see if you can match the bushing height to one of the codes there. (The mm lengths use metric nuts, while the inch lengths use Unified Extra-Fine nuts).https://www.ctscorp.com/wp-content/uploads/288.pdf

author: DrJoe
author_rank: Contributor
timestamp: May 25, 2018, 02:18:24 pm
content: Perfect! Thread won't matter as it just holds a face plate to the board. I can get a depth caliper in without disassembling the oven to measure the shaft length. The knob on this controller as well as the two adjacent knobs have been a problem as they get blasted with heat when the oven is opened and end up melting and distorted. I've replaced them at least twice. I may upgrade all 3 to aluminum knobs; I'm not worried about them getting hot and burning someone as you only use the knobs at the start of a "cook" to set the timer and wouldn't be touching them after the oven heats up . Those encoders are only about $4 from Digikey so I'm going to order a couple plus the knobs. I'll see how it goes in two weeks when the parts and my soldering stuff get to the house.Thanks so much for the info. I really appreciate it.Joe