[opendtv] Re: Diode stabilized biasing of bipolar transistors

  • From: "Allen Le Roy Limberg" <allimberg@xxxxxxxxxxxx>
  • To: <opendtv@xxxxxxxxxxxxx>
  • Date: Fri, 15 Dec 2006 14:03:57 -0500

The gentleman who originally used a forward-biased semiconductor diode to
stabilize the base-emitter biasing of a bipolar transistor was Loy Barton.
He worked for Dr. Harry F. Olson in the audio group at Sarnoff.  Loy was the
son of a missionary to China, which was the background for the unusual first
name and presumably for his pleasant quiet nature.  Loy did work on a stereo
AM radio system that used a form of QAM, as I recall.

----- Original Message ----- 
From: "Allen Le Roy Limberg" <allimberg@xxxxxxxxxxxx>
To: <opendtv@xxxxxxxxxxxxx>
Sent: Friday, December 15, 2006 9:59 AM
Subject: [opendtv] Re: PAL

> Bert's view is pretty much correct.  In the 70's Leopold Harwood developed
> circuitry that adjusted flesh tones automatically for NTSC receivers.  He
> was working in the group developing integrated-circuit TV and FM radio
> circuitry at RCA's Somerville, NJ facility.

> Leo was a great engineer with over a hundred patents, many for really
> ingenious inventions.   Perhaps his best known one was base ballasting for
> transistors, which made power transistors possible.  Leo was one of the
> first to exploit the close matching of components that IC made possible.
> Leo was actually the first to use current mirrors, though the credit is
> popularly given to Widlar at National Semiconductor.  Leo used a
> transistor to replace the diode in an earlier circuit of a gentleman at
> Sarnoff Labs whose name escapes me at this moment.
> Al Limberg

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  • » [opendtv] Re: Diode stabilized biasing of bipolar transistors