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Voltage Reference Quad Project Version 2 — Part 1

Voltage Reference Quad Project ver­sion 2 board

An updated version of the
Voltage Reference Quad Project’s circuit board.

This is my ver­sion 2 board update, which incor­po­rates sup­ply volt­age reg­u­la­tion, over-cur­rent pro­tec­tion, and trim­mer for the 5.000 volt ref­er­ence all on the same board. Continue read­ing “Voltage Reference Quad Project Version 2 — Part 1”

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Milliohm Meter Version 1.5

Update to the Milliohm Meter Project

Updated V1.5 board assem­bly for the Milliohm Meter Project.
The Milliohm Meter board V1.41 is fea­tured in Scullcom’s Milliohm Meter Udpdate YouTube video.
I had already start­ed on the ver­sion 1.5 board update a week ear­li­er and was about to send the pro­to­type files out to OSH Park for man­u­fac­tur­ing, when I noticed a new Scullcom video thru my YouTube sub­scrip­tion notice. I was pleas­ant­ly sur­prised to see that it was an update to the orig­i­nal Milliohm Meter and it was fea­tur­ing the V1.41 board that I had designed. Louis had made some sim­i­lar updates to com­po­nents, so I quick­ly updat­ed the V1.5 board file to match before send­ing it off.

Continue read­ing “Milliohm Meter Version 1.5”
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Current Projects

Current projects in various stages of completion

OpenEnergyMonitor compact EMON-TX 3.2 board
OpenEnergyMonitor com­pact EMON-TX 3.2 board

I cur­rent­ly have around sev­en projects and reviews in var­i­ous stages of com­ple­tion. Some are in the pro­to­type stage and oth­ers such as the OpenEnergyMonitor EmonTX 3.2 board pic­tured above 99% com­plete and ready to install. This EmonTX 3.2 board will be part of my home
ener­gy man­age­ment sys­tem along with a Raspberry Pi based EmonPi base sta­tion, and sev­er­al oth­er wire­less mod­ules. Continue read­ing “Current Projects”

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Programmable Voltage Reference Project

A pre­ci­sion pro­gram­ma­ble volt­age ref­er­ence cir­cuit capa­ble of 0.001 to 4.095 volt out­put in 1 mV steps with an accu­ra­cy of 100 uV.

Programmable Voltage Reference circuit board top
Programmable Voltage Reference cir­cuit board top com­po­nent side, Version 1.04

This project is based on a cir­cuit designed by uChip and pre­sent­ed in the Sparkfun forum. There is a Github page for the orig­i­nal design. Continue read­ing “Programmable Voltage Reference Project”

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New electronics workbench build

Replacing the old par­ti­cle­board desk­top with a new bam­boo coun­ter­top and adjustable leg workbench.

Electronics shop workbench
Moving some equip­ment onto the work­bench before shelve install

I had quick­ly run out of room for all my test equip­ment on my orig­i­nal desk­top table that I used for elec­tron­ics work. Leaving me around 1.5 sq/ft of usable area for my projects.
With the win­ning of an Ebay bid for a vin­tage Tektronix dig­i­tal oscil­lo­scope, I was out of room. Continue read­ing “New elec­tron­ics work­bench build”

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The DIY Open EVSE Project

The Open EVSE project includes hard­ware and soft­ware for charg­ing elec­tric vehi­cles and plug-in hybrids using the J1772 stan­dard.OpenEVSE4.23topA cur­rent DIY Open EVSE V4.23 com­plet­ed board

I start­ed work­ing with the Open EVSE project back in 2011 when I leased my first Nissan Leaf elec­tric car. Chris Howell had start­ed a post on the “My Nissan Leaf” forum and built a few pro­to­type boards to test. Then Lincomatic began work­ing on soft­ware and things began to real­ly pick up speed. Chris made the DIY Open EVSE open source on 27 October 2011, and the first boards start­ed ship­ping in late December.
Unfortunately there was a long wait­ing list to get the boards, so I decid­ed to make one for myself using the EagleCAD files pro­vid­ed from Chris.

Continue read­ing “The DIY Open EVSE Project”

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10K ohm reference resistor

A quick and easy project to mount a pre­ci­sion 10K ohm resis­tor for use as a ref­er­ence standard.

10KreferenceFront0110K resis­tor enclo­sure front panel

To go along with my Quad pre­ci­sion volt­age ref­er­ence I want­ed to add an accu­rate resis­tance ref­er­ence to my bench equipment.
I decid­ed on a 10K ohm pre­ci­sion resis­tor from Vishay Foil Resistors.
The resis­tor is a Z series ultra high pre­ci­sion Z‑Foil though-hole resis­tor with a TCR of ± 0.05 ppm/°C, Tolerance of ± 0.005 % (50 ppm), Load Life Stability of ± 0.005 %, and rat­ed at 0.6 Watts.

Continue read­ing “10K ohm ref­er­ence resistor”

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Voltage Reference Quad Project

Precision Reference Standard Quad front panel

After see­ing sev­er­al oth­er volt­age ref­er­ence projects online and many more assem­bled boards on Ebay, I decid­ed to put togeth­er my own ver­sion of a mul­ti-out­put mod­ule that I could use for pro­to­typ­ing ADC, and oth­er projects.
I need­ed at least a 2.048 volt and a 4.096 volt pre­ci­sion ref­er­ence. An extreme­ly high accu­ra­cy 5.000 volt ref­er­ence was also on my list. I already had an enclo­sure on hand that I want­ed to use, but in my ear­ly mock ups the three out­puts on the front pan­el just did­n’t look right. So for good mea­sure a 2.500 volt ref­er­ence was added to the project.

The 4.096 volt and low­er ref­er­ence IC’s only required a sta­ble 5 volt sup­ply, but the 5.000 volt ref­er­ence IC required a min­i­mum of 9 volts and prefer­ably 10 volts for max­i­mum sta­bil­i­ty. So a sep­a­rate add-on board was designed to sup­ply 9 or 10 volts along with a warm-up timer and bat­tery low volt­age alert.

Continue read­ing “Voltage Reference Quad Project”
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