CitroJim's AX, C3 Picasso, Cycling and Running Tales

[CitroJim]

The back of the board may look like an explosion in a smelting factory, but the sound that came out of the speakers more than made up for that in my view

Oh yes, all the reviews and information I have read suggests it sounds very good indeed

[CitroJim]

I thought I'd better check my Diagbox laptop as I may need it soon... I normally run it up every few weeks, if only to give the battery a charge and avoid the risk of bitrot in the SSD.

Yesterday I found the battery - a cheapie I bought from the 'bay - totally flat. Surprising as the laptop had only gone a couple of months at most since the last boot.

I fired up the laptop and the battery refused to take a charge. Although the laptop booted, it was not happy with a couple of unexpected shutdowns and blue screens in short order.

In view of the dead battery - it was showing an ominous bulge - and the age and potential sketchiness of the laptop generally, I've now retired it and rebuilt Diagbox onto my spare Windows 11 laptop.

It has a good enough battery to do a reasonable diagnostic session without needing mains nearby and a good test on my Picasso suggests it is working very smoothly.

Moral of the story is - don't buy suspiciously cheap laptop batteries from online auction sites. The one I got only cost £15 and in truth was never much good from days one!

[myglaren]

I could do with new batteries for my laptops. One was going to be £180 and I haven't found a suitable replacement for the other.
As they never leave the house it is probably another job that will never be done.

[CitroJim]

I could do with new batteries for my laptops. One was going to be £180 and I haven't found a suitable replacement for the other.
As they never leave the house it is probably another job that will never be done.

Sometimes though Steve, a failing laptop battery, even when the laptop is run exclusively from the mains, can cause unhappiness and some odd behaviour - a bit like a failing battery can in a modern car.

It's been a very busy but most excellent weekend here and the 'busy' continues well into this week so I'm sorry, there's no new progress on the amp Bobins and there's unlikely to be much this coming week either...

I'll be back to it as soon as I can...

[Hell Razor5543]

Sometimes though Steve, a failing laptop battery, even when the laptop is run exclusively from the mains, can cause unhappiness and some odd behaviour - a bit like a failing battery can in a modern car.

Often this is because the laptop is always drawing its power from the battery (due to the circuitry design), and the charger circuits (in the laptop) just charge the battery. Part of the reasoning behind this is that the laptop must remain stable when the PSU is unplugged while the laptop is in use.

[bobins]

It's been a very busy but most excellent weekend here and the 'busy' continues well into this week so I'm sorry, there's no new progress on the amp Bobins and there's unlikely to be much this coming week either...

Absolutely no problem in the slightest, Jim. It's been broken for a long time, it can remain broken for a bit longer

[myglaren]

Sometimes though Steve, a failing laptop battery, even when the laptop is run exclusively from the mains, can cause unhappiness and some odd behaviour - a bit like a failing battery can in a modern car.

Often this is because the laptop is always drawing its power from the battery (due to the circuitry design), and the charger circuits (in the laptop) just charge the battery. Part of the reasoning behind this is that the laptop must remain stable when the PSU is unplugged while the laptop is in use.

Both behave very well (probably doomed now) with the minor exception of the broadband dropping out fairly frequently, BTs fault, both the laptops, and a oddly sluggish wireless mouse occasionally, but a squirt of brake cleaner usual fixes that.
It is a very rare thing for either of them to be unplugged and one is rarely turned off.

[CitroJim]

It's been a very busy but most excellent weekend here and the 'busy' continues well into this week so I'm sorry, there's no new progress on the amp Bobins and there's unlikely to be much this coming week either...

Absolutely no problem in the slightest, Jim. It's been broken for a long time, it can remain broken for a bit longer

A bit like me then

Yesterday I had no opportunity as inter-alia I had a big job to get 560+ photos from Junior parkrun processed for today's publication deadline. I lent my camera to a fellow volunteer to do the photography - I was Run Director so couldn't - and she took about 350 more than I usually do. A big edit job was in order

To her credit, she got some cracking shots though - even catching a child on fire Look to the right by the tree

Happily, just a trick of the light on what was a gorgeous autumn morning

My recently rebuilt grandfather clock has been running well and keeping perfect time I couldn't help thinking the striking train was a bit noisier than it should be when in operation though. A quick look found the issue: I'd neglected to lubricate the fan fly shaft pivots when I rebuilt the movement.

The fan fly is a little brass vane that spins at high speed - by horological standards - to regulate the striking train speed. In effect a governor. All is now nice and quiet - except of course when the hammer strikes the gong on the hour

[Zelandeth]

Sometimes though Steve, a failing laptop battery, even when the laptop is run exclusively from the mains, can cause unhappiness and some odd behaviour - a bit like a failing battery can in a modern car.

Often this is because the laptop is always drawing its power from the battery (due to the circuitry design), and the charger circuits (in the laptop) just charge the battery. Part of the reasoning behind this is that the laptop must remain stable when the PSU is unplugged while the laptop is in use.

There were certainly some around 2003-ish (so the Pentium 4 space heater era) where the power supply actually couldn't keep up with peak demand in worst case scenarios so was actually using the battery essentially like a giant capacitor. Toshiba I'm looking at you. The ones we had at work were like that and it was a pain in the rear as they were only used a few times a year. You had to leave them to charge for an hour before you could use them or they'd die as soon as Windows attempted to actually wake up all the additional hardware.

Admittedly they weren't exactly the best machines to start with - only computer I've ever seen with three fans just for the CPU - they were incredibly loud and ran so lot that using them on anything other than a desk was completely out of the question. Both because you'd get burned if you tried to use them on your lap and the thing would overheat and crash.

[CitroJim]

Sometimes though Steve, a failing laptop battery, even when the laptop is run exclusively from the mains, can cause unhappiness and some odd behaviour - a bit like a failing battery can in a modern car.

Often this is because the laptop is always drawing its power from the battery (due to the circuitry design), and the charger circuits (in the laptop) just charge the battery. Part of the reasoning behind this is that the laptop must remain stable when the PSU is unplugged while the laptop is in use.

There were certainly some around 2003-ish (so the Pentium 4 space heater era) where the power supply actually couldn't keep up with peak demand in worst case scenarios so was actually using the battery essentially like a giant capacitor.

Exactly my experience when I was very much involved in IT hardware back in the day Zel... And the recently retired one I used for diagnostics very much fell into this category... Its PSU was/is strictly for float-charging the battery only.

Much progress on your amp yesterday Bobins. I'm well into sketching a circuit diagram of the output stages. Interesting it uses a power transistor as a giant diode in the power amplifier biassing circuit.

There'll be no progress for a couple of days now as I'm off for a short adventure. I expect the amp to be in working order very soon now

I'm enjoying workig on it; especially as I'm having to do a bit of reverse engineering...

[xantia_v6]

The trick of using a transistor B-E junction in the biasing circuit was usually to get correct temperature compensation, and the compensation "diode" would be thermally connected to the transistor it was biassing. It was often said that such transistors must be replaced as matched pairs.

[CitroJim]

Indeed Mike, it's bolted to the heatsink between the output transistors

[Zelandeth]

If a thermal camera would be useful in testing just let me know, you're welcome to use mine.

[CitroJim]

If a thermal camera would be useful in testing just let me know, you're welcome to use mine.

Thanks Zel That may well work better than my usual method - my little finger

And potentially less painful too!

[Zelandeth]

If a thermal camera would be useful in testing just let me know, you're welcome to use mine.

Thanks Zel That may well work better than my usual method - my little finger

And potentially less painful too!

Just give us a shout if you'd like me to drop it over. I'm dead short on time out not on the way to/from errands at the moment because of working around the schedule of a still young puppy but wouldn't be a problem to drop it off when I'm over that side of town.