On 07/03/2020 19:51, Clive Arthur wrote:
On 07/03/2020 12:14, Roger Hayter wrote:

snip

I suspect the pedal design is at least twice that age, probably
somewhere between 1910 and 1930.Â* Quick googling doesn't really give an
answer, but electric Singer machines were first made in 1910 and must
have had some sort of speed control.


The rheostat design was patented by Singer in 1949.Â* My guess is they
continued to use them for years because they had a warehouse full.


Probably more of the "if it ain't broken don't fix it" approach. No
point in designing something to do the same thing if you already have
the solution in production unless you are saving a lot of money by doing
so.

It's no point comparing electronic solutions using cheap semiconductors
of toady with what may have been possible with more expensive (in real
terms) less reliable power electronics of the past.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

alan_m wrote:

On 07/03/2020 19:51, Clive Arthur wrote:
On 07/03/2020 12:14, Roger Hayter wrote:

snip

I suspect the pedal design is at least twice that age, probably
somewhere between 1910 and 1930. Quick googling doesn't really give an
answer, but electric Singer machines were first made in 1910 and must
have had some sort of speed control.


The rheostat design was patented by Singer in 1949. My guess is they
continued to use them for years because they had a warehouse full.


Probably more of the "if it ain't broken don't fix it" approach. No
point in designing something to do the same thing if you already have
the solution in production unless you are saving a lot of money by doing
so.

It's no point comparing electronic solutions using cheap semiconductors
of toady with what may have been possible with more expensive (in real
terms) less reliable power electronics of the past.

And, of course, you still need a robust, reliable foot operated
transducer of some sort, even if it doesn't actually carry the motor
current.

--

Roger Hayter