TESA gage amplifier
Close
Login to Your Account
Results 1 to 11 of 11
  1. #1
    Join Date
    Sep 2004
    Location
    RSA
    Posts
    1,133
    Post Thanks / Like
    Likes (Given)
    292
    Likes (Received)
    200

    Default TESA gage amplifier

    Shot in the dark I know : I am looking for a schematics diagram for a TESA gage amplifier/readout , analog, suitable for GT21/22 probes ( if that matters ).
    I have some probes but no amplifier and I was shocked to see how much they cost. I think they're pretty simple inside and I used to be able to see myself around an electronic circuit.

  2. #2
    Join Date
    Feb 2007
    Location
    Aberdeen, UK
    Posts
    2,706
    Post Thanks / Like
    Likes (Given)
    956
    Likes (Received)
    888

    Default

    Really no need to build your own.

    Recommend you trawl ebay for one. They show up pretty regularly for peanuts.

    eg.
    Mercer 122L Bench Comparator Display Unit | eBay

  3. #3
    Join Date
    Oct 2012
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    9,240
    Post Thanks / Like
    Likes (Given)
    4986
    Likes (Received)
    4095

    Default

    Quote Originally Posted by gregormarwick View Post
    Really no need to build your own.

    Recommend you trawl ebay for one. They show up pretty regularly for peanuts.

    eg.
    Mercer 122L Bench Comparator Display Unit | eBay
    +1 even if inop or not the right match, if you have the skills, waay easier to do a repair or a mod than to roll yer own from scratch.

  4. #4
    Join Date
    Sep 2004
    Location
    RSA
    Posts
    1,133
    Post Thanks / Like
    Likes (Given)
    292
    Likes (Received)
    200

    Default

    Quote Originally Posted by Monarchist View Post
    +1 even if inop or not the right match, if you have the skills, waay easier to do a repair or a mod than to roll yer own from scratch.
    Sure, you are right. But I have no idea how they work or for which kind of probes. I understand there is more than one kind of probe.

  5. #5
    Join Date
    Oct 2012
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    9,240
    Post Thanks / Like
    Likes (Given)
    4986
    Likes (Received)
    4095

    Default

    Quote Originally Posted by AlexO View Post
    Sure, you are right. But I have no idea how they work or for which kind of probes. I understand there is more than one kind of probe.
    I'd bet that "level shifting" and ranging is the easy part as well. Might expect some linearity correction going on, too. Mapping that can get tedious.

  6. #6
    Join Date
    Sep 2004
    Location
    RSA
    Posts
    1,133
    Post Thanks / Like
    Likes (Given)
    292
    Likes (Received)
    200

    Default

    Quote Originally Posted by Monarchist View Post
    I'd bet that "level shifting" and ranging is the easy part as well. Might expect some linearity correction going on, too. Mapping that can get tedious.
    Yep, my thoughts exactly. Weird enough after hours of torturing Google, not a single diagram and ! old Tesatronic models seem to have vanished - zero data on old stuff. I suppose I have to lay my hands on one and see what's inside. The blokes at eevblog are pretty helpful.

  7. #7
    Join Date
    Sep 2004
    Location
    RSA
    Posts
    1,133
    Post Thanks / Like
    Likes (Given)
    292
    Likes (Received)
    200

    Default

    Quote Originally Posted by AlexO View Post
    Yep, my thoughts exactly. Weird enough after hours of torturing Google, not a single diagram and ! old Tesatronic models seem to have vanished - zero data on old stuff. I suppose I have to lay my hands on one and see what's inside. The blokes at eevblog are pretty helpful.
    Well, this was eventually sorted out. There are a couple of specialized ( and available ) IC's which together with a small number of passive components will make a gage amplifier be that half or full bridge. Problem solved !

  8. Likes BugRobotics liked this post
  9. #8
    Join Date
    Jun 2015
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    143
    Post Thanks / Like
    Likes (Given)
    364
    Likes (Received)
    51

    Default

    Quote Originally Posted by AlexO View Post
    Well, this was eventually sorted out. There are a couple of specialized ( and available ) IC's which together with a small number of passive components will make a gage amplifier be that half or full bridge. Problem solved !
    Hey Alex,
    Interested in the ICs you found. Something from Analog Devices?

  10. #9
    Join Date
    Sep 2004
    Location
    RSA
    Posts
    1,133
    Post Thanks / Like
    Likes (Given)
    292
    Likes (Received)
    200

    Default

    Quote Originally Posted by BugRobotics View Post
    Hey Alex,
    Interested in the ICs you found. Something from Analog Devices?
    Yep. AD698.
    Seems there are quite a few others do but this one will do the job. Bit pricey - $30 or so.

  11. Likes BugRobotics liked this post
  12. #10
    Join Date
    Jun 2015
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    143
    Post Thanks / Like
    Likes (Given)
    364
    Likes (Received)
    51

    Default

    Cool, thanks. Yea saw the same pricing. Interested in this project!

  13. #11
    Join Date
    Sep 2004
    Location
    RSA
    Posts
    1,133
    Post Thanks / Like
    Likes (Given)
    292
    Likes (Received)
    200

    Default

    Quote Originally Posted by BugRobotics View Post
    Cool, thanks. Yea saw the same pricing. Interested in this project!
    Keep in touch then. I'm tied up for aprox 2 months but after that I'll get going and try make one. It might not be cheaper than the eBay stuff but at least I know what's inside.

  14. Likes BugRobotics liked this post

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •