Re: [EE]: Interesting observations testing old capacitors from ~1973 Rotel RA-211 Amp

On Thu, 12 Dec 2024 at 15:30, Justin Richards <[email protected]>
wrote:

> ...



> An interesting observation.
> and at Altronics store measure less than the nominal value (I think they
> think I am nuts as I  randomly test their caps on the shelves)  .


Sounds like fun.
I have many suitable old candidates.

Peripheral:

Some decades back an importer had a range of toasters where one of the two
NO contacts, one in each leg, would stick on due to a mechanical assembly
issue. Which happened was random. When it was on the phase leg the
lament would be "off" but at mains potential.
Insert finger, knife, ... into slot and a possibly fatal shock could occur.
A nephew attempted to carry such a toaster with a finger in each slot.I
shudder at the thought in all cases.
He didn't die.

A talk to the importer convinced me that I needed to demonstrate the
magnitude of the problem to the relevant authorities.
I hade a simple capacitance tester to connect to the power cord via a mains
socketed cord.
Connect P&N to one mead and ground to the other.
Both leads switched - low capacitance.
One on - MUCH higher capacitance.
I visited a number of larger stores and tested toasters for sale by
plugging their power cords into my tester.
The relative prevalence (old memory says 5-10% range) convinced them to do
a product recall.
Easily fixed by correct assembly.


        Russell