{"id":20785403,"url":"https://github.com/openscopeproject/keithley1950","last_synced_at":"2025-09-09T12:46:14.303Z","repository":{"id":108345982,"uuid":"234841558","full_name":"openscopeproject/Keithley1950","owner":"openscopeproject","description":"Keithley 195A DMM Option 1950","archived":false,"fork":false,"pushed_at":"2020-01-19T04:44:27.000Z","size":1306,"stargazers_count":9,"open_issues_count":0,"forks_count":3,"subscribers_count":7,"default_branch":"master","last_synced_at":"2025-07-23T06:44:21.033Z","etag":null,"topics":["ac-dc","dmm","keithley195a","kicad","option","pcb","trms"],"latest_commit_sha":null,"homepage":null,"language":"HTML","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"other","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/openscopeproject.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2020-01-19T04:43:48.000Z","updated_at":"2025-05-10T04:07:29.000Z","dependencies_parsed_at":"2023-03-13T14:27:53.595Z","dependency_job_id":null,"html_url":"https://github.com/openscopeproject/Keithley1950","commit_stats":null,"previous_names":[],"tags_count":3,"template":false,"template_full_name":null,"purl":"pkg:github/openscopeproject/Keithley1950","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/openscopeproject%2FKeithley1950","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/openscopeproject%2FKeithley1950/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/openscopeproject%2FKeithley1950/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/openscopeproject%2FKeithley1950/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/openscopeproject","download_url":"https://codeload.github.com/openscopeproject/Keithley1950/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/openscopeproject%2FKeithley1950/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":274297357,"owners_count":25259047,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","status":"online","status_checked_at":"2025-09-09T02:00:10.223Z","response_time":80,"last_error":null,"robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":true,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["ac-dc","dmm","keithley195a","kicad","option","pcb","trms"],"created_at":"2024-11-17T14:45:27.393Z","updated_at":"2025-09-09T12:46:14.220Z","avatar_url":"https://github.com/openscopeproject.png","language":"HTML","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Keithley 195A DMM Option 1950\n\nKeithley Instruments 195A Digital Multimeter is a 5½ digit resolution 200 000\ncount instrument that was manufactured in the 80's, possibly early 90's. It was\navailable in two configurations: base model that only had DC Volts and Ohms\nmeasurements and model with 1950 option, which added DC/AC Amps and AC TRMS\nVolts measurements.\n\nKeithley DMM line has long replaced 195/196/199 series with newer models but\nthese still show up on Ebay and other outlets and they offer great performance\nfor reasonable prices. Unfortunately most of the 195A models available online\nare the ones without 1950 Option.\n\nThis project aims to recreate the 1950 Option PCB and circuitry using modern\ncomponents.\n\nIn the process some upgrades and some compromises were made. For example this\nversion of 1950 option board is based on AD8436 trms chip that along with newer\nopamps provides higher bandwidth and better overall specs than much older AD536\nof the original. On the other hand cheaper shunt resistors are used (because\nof their availability) with worse drift and tempco characteristics.\n\n**High voltage** operation using the new board is also **NOT** recommended or\ntested.\n\n---\n\n## BOM\n\nSee [bom](https://openscopeproject.org/InteractiveHtmlBomDemo/html/Keithley1950.html)\nfor this board generated by\n[InteractiveHtmlBom](https://github.com/openscopeproject/InteractiveHtmlBom)\nplugin for KiCad.\n\n## Schematic\n\n![img](https://i.imgur.com/aX9WxCY.png)\n\n## 3D render\n\n![img](https://i.imgur.com/0c3jkUk.png)\n\n## Pictures\n\nEnd result installed in the meter\n\n![img](https://i.imgur.com/UacUyqy.jpg)\n\nOriginal board next to new version\n\n![img](https://i.imgur.com/7FVghgY.jpg)\n\nClose up of rev A board with Genuine Bodge™ visible on the left\n\n![img](https://i.imgur.com/l0e0v63.jpg)","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fopenscopeproject%2Fkeithley1950","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fopenscopeproject%2Fkeithley1950","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fopenscopeproject%2Fkeithley1950/lists"}