Electro-ramblings

An Engineer in Wonderland has a new home. You can find this particular entry here. If you wish to leave a comment, please do that on the new blog.

An Engineer in Wonderland has a new home. You can find this particular entry here. If you wish to leave a comment, please do that on the new blog.

I have been having great fun messing about with motors.

A friend of mine has a new lathe.

Actually, it is an old lathe, a Mark 1 Master from Colchester. 

It weighs half a tonne (or half a ton as it is of such vintage?) and replaces an even more magnificent Colchester Triumph which literally weighs a tonne and was just a little too big for the workshop. 

An Engineer in Wonderland has a new home. You can find this particular entry here. If you wish to leave a comment, please do that on the new blog.

As part of the great lathe re-wire, I have had to learn a bit about contactors.

The starter that came with the lathe had been bolted to the front of the machine, then the front cover had been removed exposing the contactor to the world and allowing it to be operated directly by a finger. And allowing access to ground leakage paths, like fingers.

An Engineer in Wonderland has a new home. You can find this particular entry here. If you wish to leave a comment, please do that on the new blog.

As a temporary measure, I am knocking together a power supply for my LED ceiling.

The idea is to check-out the choice of brightness levels and the power circuit before I go the whole hog and make a microcontroller version.

I need to control 0-1A through an opamp and some sort of transistor, and the parts bin has yielded a CA3140 and a BUZ11 mosfet.

An Engineer in Wonderland has a new home. You can find this particular entry here. If you wish to leave a comment, please do that on the new blog.

I made up a prototype current regulator for the LED ceiling using a CA3140 and a BUZ11 mosfet, all on a chassis that I once built for a motorcycle voltage regulator.

And it worked, but current was suspiciously high on the upper settings.

Cue the scope and....oh woe.... it was oscillating as the current demand was increased.

Update: Too late, it has gone.

Thank you to all who participated.

The winner has been informed, the book posted, and we await comment.

'Alice'

We have a copy of the 'FPGA-based prototyping methodology manual' to give away.

Essentially written around Xilinx FPGAs and Synopsys development tools, it has articles by ARM, LSI and nvidia.

The authors claim it will help avoid some of the pitfalls of prototyping asics on FPGAs, and be applicable to more than just Xilinx and Synopsys products.

Before you bash off an email, there are a couple of things to think about.

Sorry to those outside the country, but we are only going to post it to a UK address.

We would rather you at least have a desire to read about FPGA-based prototyping, rather than a uncontrollable urge to make some cash on ebay.

And it would be nice if you could send back a comment or two on the content after you have opened it - particularly if you feel it is broadly applicable.

First email to alice@electronicsweekly.com with BOOK in the subject gets it.

An Engineer in Wonderland has a new home. You can find this particular entry here. If you wish to leave a comment, please do that on the new blog.

Thanks to the kind contribution of Mr Williams from Swansea, I now have a copy of Professor Eric Laithwaite's informative chart, which puts the physical world in perspective by equating its metrics to electrical parameters.

Actually, Mr Williams sent it to me over a month ago, but I mislaid the email, for which I apologise to him.