
Just for once
A useful SWOT analysis!
72 publicly visible posts • joined 1 May 2013
Back in the analogue world, I used to supply pencil galvanometers, which had a max current of 75 mA in most cases. These were not cheap, at around 200 pounds an item.
Some expert in a stores decided to test a batch of these with an AVO 8 - which was capable of a couple of hundred mA if I remember correctly. I think they got through 100 or so before figuring out that they have made an error........
when people find out that stored energy has the potential to do harm as well as good.
(by the way, not intended to offend anyone here - I'm assuming the average El Reg reader is one of the enlightened!)
Energy, by it's nature, has to be managed. the management challenges vary on the type of energy and the type of storage.
I'e had similar within Europe. I was tech support for a range of digital panel indicators, and these were supplied from my English employer to our french importer to a local distributor to a panel builder for a new bakery conveyor oven for a large french bakery. The RS485 comms on these panel indicators was simply not talking to their computer.
With a bag full of laptop and testgear, I arrived on site with the importer to find the bakery company, the oven manufacturer who was supplying the computer and RS485 controller, the panel builder and the local distributor all on site ready to give me a hard time.
I requested 30 minutes to set up my testgear, and the crowd went off for a coffee, and I tested the indicators, and all looked good, they all worked correctly.
When they came back from their coffee, I showed them that the indicators were all good - which was followed by a collective shrug, and the inevitable "why are they not working with our RS485 converter" I requested the manual for the converter, and it showed that they had connected everything correctly - except for two optional wires.
I said - why not connect those?
They said - we never need to.
I said let's try - and 30 seconds later all was working perfectly.
The bakery owner was furious with the oven supplier - who lost huge amounts of face by having an english guy read a french manual and add two wires that had delayed the project for several weeks. I thought our french importer was going to explode - he was trying so hard not to laugh!
There used to be a standard for writing test procedures used in part of the armed forces, and these had to be of the detail of:
1) remove device under test from from travel case
2) plug power lead into device
3) plog power lead into test supply socket
4) switch on device
5) Connect red lead from red socket on device to red socket on test source
6) connect black lead from black socket on device to black socket on test source
7) ensure test source outlet switch set to zero
8) switch on test source
9) allow all to stabilise for 20 minutes
10) ........
It's mind bending to write, and even then stuff can go wrong!
The short answer is to reduce fire risk. a short in a light bulb, connected to a 30 A circuit, can cause ignition long before the circuit protection operates. the same short circuit in a 5A circuit is much more likely to cause the circuit protection to operate.
The other benefit is that the lights don't go out if the appliance circuit goes over current (like when my compressor trips out the circuit in my garage, and plunges me into darkness)
Condolences to Sir Clive's family
I never met the man myself,
I had one of the kit scientific calculators - reverse polish notation, ate AAA batteries for breakfast, lunch and tea, but was a real calculator that people could make and use for tiny money.
My first programming was on a borrowed Heathkit 6502 machine (late 1970s?), but the Spectrum was the computer that really got me into programming, with the "one touch" basic, and the odd PEEK and POKE to liven things up!
Sir Clive's biggest contribution is to make a whole generation of people willing to take on computer technology - before the spectrum, computing was a niche activity, after the spectrum, computing was for the masses.
Rest in peace.
is the stocking mask and the sawn-off shotgun.*
Anti-monopolistic, anti trust, labour protection and inside trading legislation which are punitive and enforced are the tools needed to ensure that stuff like this doesn't happen. While large corporations fund politicians, though, there are limits to the likelihood of sound regulation being put in place.
*I got this from Mike Harding, the UK comedian/folk singer, but he may have got it from somewhere else!
I recall on one occasion going to sort out a "my PC won't power up" issue, where the user had elected to plug the 4 way adaptor back into itself.
They appeared to think that, as long as it was plugged in somewhere, all would work. Unplugging the adaptor from itself, and then plugging the adaptor into a wall socket magically fixed the problem.
I seem to recall "editing" command.com to disable del as a command., forcing use of erase. Somehow, typing the 5 character command rather than the 3 character command would give me just enough pause to dramatically the occurrences of erroneous delete, and reduced the workload on my pctools disk dramatically