What Did You Do Today (2016)

Search for 'online python tutorial' there are some really good ones based on interactive real-time python 'consoles' on line.

Neil

Neil,

By no means rooinek (I could type another, but that's not for family viewing)

Each language has the appropriate word/s to describe ones feeling much more succinctly than the other, and when combined, one feels so much better.

I haven't spoken much Afrikaans since 2002 when on holiday in PE, and with English being my native tongue I use A-S most of the time, but 'foreigners' do creep in every so often.

Dare I admit I can say Afrikaans words to all and sundry, with a smile on my face, and have no fear of being on the wrong end of a 'fiver'

Just spent the whole day looking at Facebook photos taken at the original Kyalami F1 circuit

Geoff - That wonderful circuit now castrated , but my memories racing there survive.

If you have not done so already join the raspberry pi forum.

https://www.raspberrypi.org/

By all means google first but there is a lot of help available on the forum. Be sure to include the line that gives the error and the erreor message.

Hi JA,

I've used Python on a Raspberry Pi 2 and it all works fine. You're probably tripping over something simple like trying to execute Python3 code with the Python2.7 interpreter. What was the error message?

Cheers,

Dave

Thank you all for the advise on python. I am aware that there are differences between versions 2 and 3 and have tried both with the same result. I have joined the python forum and posted my problem. I will wait and see what happens.

JA

Pulled onto the A38 this morning, after about half a mile, battery light flashed on, then went off. Slipping belt?

Then found myself on the end of an 8-mile queue moving at sub-walking pace/

A mile or two further, light came on. Then speedo and tacho died. Then each system on the car started dying in turn... tried turning things off but the heater and heated seats wouldn't switch off! Gradually everything dies except engine - pull over rather than wait for inevitable.

After half-hour in queue, my wife collects my daughter, but another 40 minutes for the AA to get through, swap in a full battery and get home with everything switched off after another 20 minutes in the queue, alternator light on all the time now. Time for a new alternator, and suspicion on battery given how fast it died.

B***r

Sounds like the regulator. Used to be a few quid and DIY but now probably can't change it as a part and have to chuck the whole engine.

must of been in the 1970's the Lucas alternator on my dads Vauxhall viva stopped charging

the ignition light went out when the engine was started but came back on soon after

luckily the thick film regulator was encapsulated in silicon rubber that made it easy to remove and test the various components

half an hour later , after replacing a faulty transistor with a ZTX107 the alternator worked on the bench

had to wait for a tube of electronic grade silicon sealant to arrive from Radio Spares (RS Components) - not the common DIY sealant that gives off acidic fumes !

the last time I checked an alternator (Bosh) the regulator was combined with the brush holder - easy to replace

not sure how cost effective

John

PS if I remember correctly it was Q1 that I replaced

Edited By john swift 1 on 20/01/2016 15:00:53

The AA chap reckoned that with this alternator you can pull off a certain connection (possibly the sense connection?) and if its the regulator gone it will then output a straight 14.4V. He did and it didn't

Neil

Haha. If it regulated at 14.4V magically without a regulator, why would they bother fitting them?

"the last time I checked an alternator (Bosh) the regulator was combined with the brush holder - easy to replace not sure how cost effective" - you can design everything to be easily serviceable but the Japanese lesson was that it's cheaper overall (total cost of ownership etc) to design it so it doesn't fail in the first place. It's arguable that the brushes are serviceable items, so at least this approach doesn't require the whole alternator to be scrapped.

I thought the alternator gave out AC and it was turned to DC at about 14.5 V, alternators give volts at low speeds.

What i have found is that the brushes wear and skip and cause output problems, replacement is quite simple. Also brush dust can cause problems.

As an aside Yachts trail a propellor on a cable attached to an alternator in a bucket and sealed watertight to give battery charge while sailing, but fish take the prop thinking its bait. I know a sailor who lost at least 3 on an Atlantic trip.

The Lucas Car Alternators had radial slip rings, one common cause of failure on higher mileage cars was the outer brush wearing much more than the centrally located one. That also tended to cause an uneven wear pattern on the slip rings.

The rotor could be removed and the slip rings skimmed in a lathe, we only ever risked doing that to any particular alternator once.

Generally speaking the Alternators were pretty reliable and better than dynamos at keeping keeping the ever increasing electrical loads going.

Edited By V8Eng on 20/01/2016 17:17:45

Neil, get a quality rebuilt unit.....

.with down time and all the trouble finding parts not worth the effort and remember the brushes, bearing etc will be on their way out as well.....

be careful there is a lot of rebuilt units from Serbia, Romania etc on flee bay .....

there are quality UK rebuilt units out there, they are just not the cheapest......

clogs

It does there is a rectifier that converts it to DC then a regulator to give the correct DC voltage usually all built into the alternator. Lot easier on most motor cycles which have a stator and seperate reg/rec unit that lets you troubleshoot a lot easier.

I want a quick get-going solution. I may just swap the brush box over, and if that's the fault I might recon the old one because with 4 of the same car in the family it won't be long before another is needed .

Neil

Walk into a car spares place and get a service exchange. That way you know you hav​e an as good as new alternator.

Edited By jason udall on 20/01/2016 18:47:50

I think he wasn't meaning exactly 14.4V, rather that the flat battery's voltage starts rising towards it if the regulator is disabled.

Plus no profit in alternators that don't fail...

Jason - he disconnected and reconnected everything, including the battery.

Neil

Edited By Neil Wyatt on 20/01/2016 19:45:26

JohnSwift 1, its a shame they did not put a 100 ohm resistor inside the unit between the sense and the output wires, if the sense wire becomes detached the charge goes to max and boils the battery. If Q3 goes short circuit, the voltage rises and blows every bulb in the car and the computer. . . ..

Frank

I understand they made 2 versions of the alternator

one with the sense wire measuring the voltage at the positive battery terminal and another internally linked to the alternator positive output

if the sense wire is disconnected you have no positive supply to R4 which supplies the bias to switch on transistors Q2 and Q3

I guess if Q3 goes short circuit , the alternator will be so hard to turn at speed the belt will start to slip and screech

unless your answer to any  new noise is to turn up the radio a bit louder

you should find the fault before the battery is boiled dry

John

Edited By john swift 1 on 20/01/2016 20:26:51