"Jim Lesurf" wrote in message
...
In article , David Looser
wrote:

They do not necessarily clash. By what criterion were they "expensive"?

The thermal delay relays used were the order of a couple of quid *each* in
quantity, back in the 1970s. Compare that with the few pence per diode
bridge for better diodes that didn't need the delay. Plus of course the
savings to all involved when the change had a quite marked effect in
lowering the numbers being returned for repair because the thermal delay
was unreliable.

You'd expect thermal delay units to be expensive compared to diodes. But a
couple of quid each is cheap for thermal relays.

What measurements did you do on the delay unit we are discussing? And
how
many of them did you check, and over what period of time?

Well clearly I made no measurements. I only had one unit to examine and it
had already failed by the time I examined it. But I do understand how the
things work, and have met a number used in different bits of kit over the
years. So I do know the limitations of the device.

I note your personal opinions. Perhaps you missed some of the things I
wrote. :-)

I don't think I missed any, though you seem to have missed the point that
making judgments on the reliability of electromagnetic relays based on your
experience of an *entirely different* device seems, at best, hasty!

David.