27 Apr
2011
27 Apr
'11
7:20 a.m.
On 04/27/2011 03:01 AM, arcarlini at iee.org wrote:
Chuck Guzis [cclist at sydex.com] wrote:
That was a wide spread application for negative feedback and
level controls.
My Measurements M803A signal generator (6CW4 nuvister for Osc)
has a 7W sewing machine lamp in the solid state audio oscillator.
I've seen that same arrangement used in many audio generators
of the Wein Bridge type. I've also seen thermistors with both positive
and negative temperature coefficients used for that purpose.
It's not forgotten and its old.
Allison
It was common knowledge in the 1930s. I have a
"Radio Engineering"
handbook from the late 30s that shows the consutruction of an audio
signal generator using a common panel lamp for temperature
compensation.
I saw the technique used once in a Practical Electronics article
sometime
in the 1980s (or thereabouts). So I don't think it was forgotten, just
not used very often.
Antonio
arcarlini at iee.org