Precision Voltage Reference

So +Scullcom Hobby Electronics released a video about updating the voltage reference he originally designed. And after a rummage in my parts box, I managed to find a few more IC's that should do the job:

A Little Rummaging...

Primarily I needed a voltage reference: I found a REF03GP - 2.5V reference with an initial accuracy of up to 0.6% (15mV) and a Tempco of anywhere between 10 & 50ppm/^oC - not the best but good enough, hopefully can trim it out.

Next on shopping list, Voltage doubler: I found three INA134's - like a INA105, but for audio applications. Seen as we are working with DC, I don't think this will be an issue. So now I can go from 2.5V, to 5V, to 10V using 2 of these amplifiers. Not sure how close the 10V will be after 2 stages of amplification, but will see.

Next; a split rail generator: closest I could find was a ICL7660 - meaning I could make a negative rail, but also means I have to generate my own positive rail. Hmmm... will have to do some digging or maybe design a voltage multiplier or joule thief?

Brief description of the circuit

I'll be using a 9V PP3 cell to power this project, with associated protection circuitry, battery monitoring and indication. The 9V cell will power the reference and the split rail generator.

The split rail generator will power the Op-amps only, so it doesn't have to be high power.

The reference will then be amplified once to 5V by one amp and then again by the second amp to 10V. I'm hoping that the 10V isn't so far out after the second round of amplification that it makes it useless, but we'll seen on the breadboard.

Proposed System

And then...

Once I've tested it on a breadboard, I'll then solder it up on some strip board and then stick it in an enclosure with some binding terminals

Update and Project Ideas

Update

well its been a while, yet again! Where's it in a nut shell:

1. New Job! I now work as a lab Tech at the university of York's electronics department. Thus returning to the very place I obtained my degree! The amount of fabrication and development technology at my disposal is epic now and hope to deploy some of it for some up and coming projects (including a PCB isolation router)! The works good and taxing, but very satisfying! Another plus is I am now trained up on a new PCB CAD package: Proteus and having a crack at KiCAD on linux in my spare time.
2. I'm getting married! (finally some would say!)
3. Looking after the kids. Yes the small screaming things that I love dearly are becoming more of a handful each week and as such, the Daddy hat has to come out!
4. Have had to come to terms with parting with the landy! I know but, its been sitting for ages and with the kids and everything, I need to do the last few jobs on here and she's going to a better place. I'd rather she here used more than gathering moss on the driveway. I can always pick up a new project in the future.
5. The welder is still on the back burner. The reason for this is explained below.

Project ideas

Recently I've been watching some youtube vids and reading some articles on voltage standards, and test equipment.

After a quick stock take of my parts bin I found I had enough spare bits to build a constant current source. This lead onto looking at voltage standards and resistance boxes. All this is well and good but I'd also need a PSU to develop these projects - further digging in the scrap bin yielded some high value parts that would take the sting out of the projects total cost. A PSU would also help develop my welder project at home too.

So I set a mission brief:

Construct a PSU, Constant current source, voltage standard and resistance box for as cheap as possible and constructed out of as many recycled parts as possible. Maximum cost of parts must not exceed £20 for each piece of equipment.

Weather this is possible or not, I don't know, but I'm pretty good a scavenging! So i'll be fun to try and find these parts in other bits of broken old kit!

I'll post something up soon, bits and bob's later about progress I've currently made and will be making.