Rotary Encoders for TDS210 - Page 1
Forum section: electronics / projects

author: aramosfet
author_rank: Contributor
timestamp: September 08, 2012, 01:21:33 pm
content: Hi All,Recently a generous colleague of my dad donated me an old TDS210 scope with a faulty Display panel. I some how managed to get a replacement and fixed it. But now I see the front panel knobs don't work properly. The volt/div and sec/div occasionally jumps around even if i'm turning it in one direction. Now I couldn't find any information about the front panel boards online. I was hoping i could at least replace the rotary encoders on the board. But there's no part number on the rotary encoders, Just the manufacturer logo "Bourns" is visible.My question now is, Does someone know the part no's of these encoders ? I'm not sure if they are even available now. If not, Is it possible to find a replacement for the entire front panel?Thanks,

author: firewalker
author_rank: Super Contributor
timestamp: September 08, 2012, 01:42:47 pm
content: Some photos would help.Alexander.

author: AndyC_772
author_rank: Super Contributor
timestamp: September 08, 2012, 01:46:59 pm
content: I have a TDS3034B at work which is much the same, the vertical adjustment has a mind of its own.There are a couple of dead TDS210's on Ebay right now - you could perhaps try and pick up one of those and swap the parts over.Bourns is a well-known manufacturer of this type of product. Have you tried asking them if they can supply a replacement? You never know...

author: aramosfet
author_rank: Contributor
timestamp: September 08, 2012, 02:08:23 pm
content: Couple pics of the Front panel and rotary encoder.

author: free_electron
author_rank: Super Contributor
timestamp: September 08, 2012, 02:29:40 pm
content: These are custom. You cannot remove the encoders. Tektronix is so cheap they use the pcb as the encoder condact and the bourns part is simply hot melted onto the pcb.Where are you located ? Give me the exact markings on the pcb. I will dig in my 'dead tek' box. I may have one of these ...

author: senso
author_rank: Frequent Contributor
timestamp: September 08, 2012, 02:29:48 pm
content: Can you show a photo from the other side?From the shape and color, those are either EAW or ES series, the first line of photos:http://www.bourns.com/ProductLine.aspx?name=contacting_encoders

author: aramosfet
author_rank: Contributor
timestamp: September 08, 2012, 02:54:28 pm
content: free_electron, Your're right. I don't see any pins either on the component side or solder side. The encoder "legs" are melted on to the pcb.I didn't find any other markings on the pcb apart from the bar code with the Part no and the Date codeThe Part no is 679-3743-00. I'm in Bangalore, India.Now, I see two more options. If I can get an equivalent part, I might me able to hack the faulty encoders and "wire wrap" another encoder with similar detents and resolution spec. The other option is, looking at the board, the interface seems simple enough with a 5pin connector. There are a couple of 8:1 analog muxs (74HC4051) and a binary ripple counter (74HC393) on the solder side. If I can reverse-engineer and learn how it works, I might be able to drive the interface with a 8 bit micro and diy keypad and available rotary encoders.Its only the two Volts/div and sec/div encoders that I need to worry about. The others are working fine.Thanks

author: aramosfet
author_rank: Contributor
timestamp: September 08, 2012, 03:16:18 pm
content: Quote from: senso on September 08, 2012, 02:29:48 pmThe EAW series is an absolute encoder. I don't think the scope needs to know the position of the encoder, Just the step and the direction should be enough. I think it should be a variant of the ES series.