Author Archives: daqq

New method for measuring lots of resistors using very few wires – part 3 – a simple measurement device

The hardware implementation The previous bits of the article ( part 1 and part 2 ) described the core concepts of this measurement and the theory behind it. The actual measurement device – the measurement system is pretty simple when … Continue reading

Posted in Resistance measurement method | Tagged , , , , , , | Leave a comment

Davids bile giveaway – Subscription? No, thanks.

Warning: NSFW language. So, Autodesk bought Eagle. This in and of itself would not necessarily be bad news – Eagle has been in need of some improvements for some time, and occasionally, when a bigger company assimilates a smaller company … Continue reading

Posted in Rant | Tagged , , | Leave a comment

New method for measuring lots of resistors using very few wires – part 2 – Theory

The Matrix Continuing from part 1 the matrix form used needs to be described. If you need a quick “tutorial” in systems of linear equations, take a look at this text I wrote. First, the vector of the unknowns – … Continue reading

Posted in Projects, Resistance measurement method | Tagged , , , , , , | 4 Comments

New method for measuring lots of resistors using very few wires – part 1 – Theory + intro

Introduction This article describes a new method of measuring a lot of resistors using a low amount of wires and a lot of math. The resistors can be any kind of resistors, thermistors or other resistive sensors. It can be … Continue reading

Posted in Projects, Resistance measurement method | Tagged , , , , , , | 2 Comments

GPIO abuse – sourcing and measuring at the same time

The GPIO (General Purpose Input Output) pins are the pins of a microcontroller (or other device) that can connect the device to the rest of the world, without having a particular dedicated function. In contrast to pins dedicated to a … Continue reading

Posted in Tutorials & explanations | Leave a comment

Overdetermined system of linear equations

Introduction This text is a quick post that should give a quick explanation on (overdetermined) systems of linear equations, particularly their matrix form. It is for an upcoming article that deals quite a lot with these systems. Warning: Please note … Continue reading

Posted in Tutorials & explanations | Tagged , , | Leave a comment

Repair/teardown – FlexiScale weight and calculator scale

I love going to the flea market – you find all sorts of fun stuff, bargains, trash and the occasional treasure that is being sold for next to nothing. This posts fits into the ‘fun stuff’ area – while at … Continue reading

Posted in Measurement tech | Tagged , | Leave a comment

L110 METRA Blansko resistance decade box

Recently I got a L110 resistance decade box made by METRA Blansko, in former Czechoslovakia. Unfortunately something was rattling inside, so I had a quick look inside to remove the offending part – it was a small metal nut that … Continue reading

Posted in Measurement tech | Tagged , , , | Leave a comment

Circuit Cellar publication – a new method for measuring resistors!

Dear readers, After lots of work, waiting and experimenting, I have completed a text that I have sent to Circuit Cellar and they have agreed to publish it. The article deals with a new measurement technique designed to measure lots … Continue reading

Posted in Other, Projects | Tagged , , , , , | Leave a comment

HP 9000 Superdome utilities board ( A6475-60201 ; UGUY5-500 ) high res scan + guesswork

While on a buying frenzy at a local radioamatuer gettogether (Holice 2014) I saw an interesting looking PCB – apparently taken from some kind of older HP system, it had some very nice oscillators (500, 525, 100, 126 MHz), some … Continue reading

Posted in Miscellany, Vintage tech | Tagged , , | 1 Comment