COMPLETE REF200 LOW CURRENT REFERENCE STANDARD KICAD PROJECT - FREE - Page 1
Forum section: electronics / projects

author: t1d
author_rank: Super Contributor
timestamp: June 02, 2019, 02:46:33 pm
content: I spun up my own version of this REF200 Current Reference Circuit in KiCad. It was inspired byhttp://www.scullcom.uk/category/projects/low-current-reference/It has four ranges - 100uA/200uA/300uA/400uA.I was able to use just two jumpers to create all of the permutations and combinations of the switch. See the notes on the schematic. This created a "real estate" savings and avoided the (considerable) cost of the switch. The PCB is just 12x19mm, IIRC, and can be had at OSH Park for $1.85/3 Copies/Shipped-(Anywhere, I think.)My version is intended to be strapped to a 9 volt battery, with a rubber band. The Lead/Probe pads are large enough to forego the banana jacks.I highly recommend SamTec brand high-temperature header pins, for the jumpers and such.I could use some help with proofing it, for the 434 time... <g>Anyway, you are free to do anything that you wish with the attached KiCad Project, given my release of liability, of course. See below.WARNING: RISK OF ELECTRICAL SHOCK AND AUTHOR IS NOT AN ELECTRICAL ENGINEER.FREE FOR ANY AND ALL USE, PRIVATE AND COMMERCIAL, GIVEN THAT THE USER WHOLLY INDEMNIFIES, RELEASES AND HOLDS HARMLESS ALL AUTHORS AND DISTRIBUTORS FOR ANY AND ALL CLAIMS, SUITS, JUDGMENTS, AND THE LIKE, INCLUDING COSTS OF DEFENSE, ARISING FROM, OR OCCURRING IN CONNECTION WITH SUCH USE OF ANY AND ALL PROJECT MATERIALS. SHOULD USER PREVAIL AGAINST ANY AUTHOR, OR DISTRIBUTOR, CONTRARY TO THE INTENT OF THE ABOVE, USER AGREES TO ACCEPT LIQUIDATED DAMAGES IN THE AMOUNT OF $10 AS FULL SETTLEMENT THEREOF.EDIT: TYPO CORRECTED;MIDIGATED= LIQUIDATED

author: soldar
author_rank: Super Contributor
timestamp: June 02, 2019, 02:50:07 pm
content: Let me consult with my lawyer and I'll get back to you.

author: t1d
author_rank: Super Contributor
timestamp: June 02, 2019, 05:09:03 pm
content: Quote from: soldar on June 02, 2019, 02:50:07 pm

author: OM222O
author_rank: Frequent Contributor
timestamp: June 02, 2019, 07:34:38 pm
content: I actually made my own similar version, but with a normal switch rather than the rotary type. using jumpers is a bit painful compared to a simple switch IMHO.

author: t1d
author_rank: Super Contributor
timestamp: June 02, 2019, 09:55:43 pm
content: Quote from: OM222O on June 02, 2019, 07:34:38 pmYeah, Louis at Scullcom made a very nice lab-grade instrument, having a proper box, switch and banana sockets... I wasn't going for that much sophistication...The switch he used is a rotary 3P4T... Cheapest at Mouser is over $5USD... With the REF200 being so expensive, I wanted to cut some corners. Jumpers are just pennies... I will use the savings for more electronic toy stuff...This is actually one half of a set... The other being a Precision Voltage Reference Standard built off of a MAX6350... I have the board and its parts on order, too... All good for calibrating my decades old lab equipment... I hope to post that project, soon, as well...

author: iwtommo
author_rank: Contributor
timestamp: June 02, 2019, 11:09:31 pm
content: Hello i built your circuit and got shocked while doing it. I was not using the materials/parts you listed exactly the exact arrangement and/or layout of design is what caused me to get hurt. It really hurt and i seek the $10 damages in lost time having a beer to calm down.