Craig Sawyers

Gabriel's Moon by William Boyd. Un put downable. Although recently published it is the first in a trilogy.

There are stories both ways about electrolytic capacitors. As an example, I have an AVO transistor tester (just for historical curiosity; an early 1960's beast). The large circuit board is rammed full with Plessey axial electrolytics, and had not been powered for decades. They all measured just fine with my PEAK ESR meter (it also reads capacitance too). So I just fired it up - works perfectly. But the dreaded power supply and output electrolytics in the old Quad 303 power amp were arranged so the vent faced downwards towards the circuit boards. Quad got steady returns as a result of rotted circuit boards because of electrolyte venting, eventually doing what they should have done originally and put the vents upwards. And the old Sprague "twist-lock" electrolytics eventually disconnect themselves because of the outer foil being crimped into a steel closure - so the foil suffers from dissimilar metal corrosion. Modern electrolytics are physically much smaller for a given voltage, capacitance and ripple rating. This is really a mix of more highly etched foils and improvements in electrolyte chemistries. But they tend to be more highly stressed - and lifetime goes as the Arrhenius equation. The lifetime of the capacitor halves for every 10C increase in temperature. The flip side is that if you conservatively rate the capacitor, its lifetime will exceed the lifetime of the engineer. As an example, suppose the capacitor lifetime at 85C is 2000 hours (about 3 months). If it is run at 35C, being 50C under the maximum increases the lifetime to 2^5 x 2000 hours, or 64,000 hours, or 8 years if turned on permanently. If it is turned on say 3 hours a day, the lifetime of the capacitor should be 64 years. By which time I would be 123 years old and long being with the choir eternal. Of course this is a idealistic calculation, and rubber seals will have degraded enough to cause the capacitor to fail much earlier than that.

Um - where's the speakers? Not the bijou bookshelf ones, surely.

Happy birthday from across the pond!

I've seen similar stickers in the UK.

Oh poor cat. As a cat lover, it is always a lurch when they go. And Sam was still a young cat.

Slight health scare. Went down with the "cold from hell" in October last. And it seemed to come back four or five times over the next 5 months. Feeling wrecked most of the time. Considered Covid, so took a test - negative. Eventually made an appointment, and saw the Trauma nurse at the practice. Put a blood oxygenation clip on, and sounded my chest "It sounds really rattley ". So packed into one morning in mid March, I ended up with a course of kick ass antibiotics, a full spectrum blood test, and a chest X-ray. Saw the Trauma nurse again yesterday. Antibiotics worked wonders, so the problem must have been an opportunistic bacteria had moved in. Blood test was all nominal (who knew there were 5 different kinds of white blood cell; not me), and chest X-ray was completely clear. So finally after 5 months of recurring misery, I'm finally firing on all cylinders again! Back in the gym, leading 14 mile walks, and running. Happy days!

RIP Val Kilmer. Age 65 from pneumonia, having survived throat cancer.

Have a great day! Happy birthday!!

That is Hannah Fry, PhD in Maths and does a great deal on the public understanding of maths and science (we do lots of different Math in our country🤓). https://en.wikipedia.org/wiki/Hannah_Fry

The Audio Research 610T, which is what they are, 800W each idling power. So 1.6kW of heat going into the room. Made from 2005 to ? Now replaced by the not dissimilar 750SEL monoblocks. A bit like Rolls Royce - if you need to know the price, you can't afford one. But if you need to know, a hair under $100k a pair

Classic special effects movie, with an impossibly young looking Leslie Nielsen. Loosely based on Shakespeare's play The Tempest.

Went to see this yesterday https://trh.co.uk/whatson/the-score/ . Amazing production.

I had a pair of ESP6's in the late 70's. Glorious sound, heavy (because of the transformer and voltage multiplier in each cup) and sweaty because of the fluid filled cups. And needs to be connected to the loudspeaker output of a power amp. I could just about survive a side of a record, and then a break to let my head recover.

Alternatively

Woah - how did I miss this? Very happy belated Nate!!

Have a great woody day Steve! Happy birthday from the other side of the pond!!

That is an impressive device! And cheap as chips at UKP 0.38 (although it is very similar in USD or Euro now) from Mouser in one off.

Or even the DXTP560BP5 . PNP, 500V, 150mA and 2.8W Surface mount of course....

Any thoughts on the PZTA96ST1G ? Surface mount SOT223, PNP, 450V and 500mA. Downside is 1.5W power dissipation. At least the darned thing is still available

KSA1156 is of course obsolete, alas. OnSemi seem hell bent on obsoleting anything remotely useful from the inventory of companies they acquired. If it does not go in a mobile phone, flat screen TV, PC or car or anything with huge volume, they lose interest real fast. Any that are on eBay are >90% fakes

The bizarre thing with the Sanyo datasheet in the subject line says NPN, but the actual data is all negative going - which would only be the case for a pnp. Of course all the AI data scrapers only consider the (incorrect) Sanyo tag line of NPN - and that forms the basis for every human on the web to propagate that nonsense. Or the other way round - it matters not. As Kevin says - the 2sa1968 is a pnp

A very belated one Jeff - hope you had a great day!

Eating humble pie. The original diagram was correct. I had to draw up the truth tables to convince myself! Clearly very rusty now with Boolean logic. I used to be a dab hand.

The two captions on the bottom right are the wrong way round. The NOR gate in the bottom middle would do not(South or Africa) and the bottom right, a NAND gate would do not(South and Africa).