If you had one what would you use it for
in [Design]
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From: brent on 21 Oct 2009 19:58 On Oct 21, 10:51 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: > On Wed, 21 Oct 2009 07:37:36 -0700, John Larkin > > > > <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >On Wed, 21 Oct 2009 06:21:02 -0700 (PDT), MooseFET > ><kensm...(a)rahul.net> wrote: > > >>Imagine you had a sensor that could measure very small magnetic > >>fields. It measures with a noise floor of about 0.1fT. Unfortunately > >>the band width is only a few hundred Hz and it only works inside a > >>shield. > > >>What would you use such a sensor for? The best I've thought of is > >>detecting the flow of current in a PCB to find a short circuit. > > >You need high spatial resolution for a general-purpose board short > >finder. Magnetically, you can do it with a pulsed current source and a > >really tiny ferrite-core pickup coil. I do it lately with a DC source > >and a thermal imager, so you can *see* the current path. > > >John > > A microvolt meter makes short finding trivial. Somewhere back in time > I posted how I made my own at GenRad in the late '70's > > ...Jim Thompson > -- > | James E.Thompson, CTO | mens | > | Analog Innovations, Inc. | et | > | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | > | Phoenix, Arizona 85048 Skype: Contacts Only | | > | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | > | E-mail Icon athttp://www.analog-innovations.com| 1962 | > > Cranky Old Git With Engineering Mind Faster Than a Speeding Prissy Did you woek at gen rad? I got some questions about someone I knew that worked there in that time frame
From: Jim Thompson on 21 Oct 2009 20:05 On Wed, 21 Oct 2009 16:58:33 -0700 (PDT), brent <bulegoge(a)columbus.rr.com> wrote: >On Oct 21, 10:51�am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- >Web-Site.com> wrote: >> On Wed, 21 Oct 2009 07:37:36 -0700, John Larkin >> >> >> >> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >On Wed, 21 Oct 2009 06:21:02 -0700 (PDT), MooseFET >> ><kensm...(a)rahul.net> wrote: >> >> >>Imagine you had a sensor that could measure very small magnetic >> >>fields. �It measures with a noise floor of about 0.1fT. �Unfortunately >> >>the band width is only a few hundred Hz and it only works inside a >> >>shield. >> >> >>What would you use such a sensor for? �The best I've thought of is >> >>detecting the flow of current in a PCB to find a short circuit. >> >> >You need high spatial resolution for a general-purpose board short >> >finder. Magnetically, you can do it with a pulsed current source and a >> >really tiny ferrite-core pickup coil. I do it lately with a DC source >> >and a thermal imager, so you can *see* the current path. >> >> >John >> >> A microvolt meter makes short finding trivial. �Somewhere back in time >> I posted how I made my own at GenRad in the late '70's >> >> � � � � � � � � � � � � � � � � � � � � ...Jim Thompson >> -- >> | James E.Thompson, CTO � � � � � � � � � � � � � �| � �mens � � | >> | Analog Innovations, Inc. � � � � � � � � � � � � | � � et � � �| >> | Analog/Mixed-Signal ASIC's and Discrete Systems �| � �manus � �| >> | Phoenix, Arizona �85048 � �Skype: Contacts Only �| � � � � � � | >> | Voice:(480)460-2350 �Fax: Available upon request | �Brass Rat �| >> | E-mail Icon athttp://www.analog-innovations.com| � �1962 � � | >> >> Cranky Old Git With Engineering Mind Faster Than a Speeding Prissy > >Did you woek at gen rad? > >I got some questions about someone I knew that worked there in that >time frame I was Analog Guru at GenRad Portable Products Division, Phoenix, from 1977 to 1987. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Cranky Old Git With Engineering Mind Faster Than a Speeding Prissy
From: brent on 21 Oct 2009 20:35 On Oct 21, 8:05 pm, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: > On Wed, 21 Oct 2009 16:58:33 -0700 (PDT), brent > > > > <buleg...(a)columbus.rr.com> wrote: > >On Oct 21, 10:51 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- > >Web-Site.com> wrote: > >> On Wed, 21 Oct 2009 07:37:36 -0700, John Larkin > > >> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >> >On Wed, 21 Oct 2009 06:21:02 -0700 (PDT), MooseFET > >> ><kensm...(a)rahul.net> wrote: > > >> >>Imagine you had a sensor that could measure very small magnetic > >> >>fields. It measures with a noise floor of about 0.1fT. Unfortunately > >> >>the band width is only a few hundred Hz and it only works inside a > >> >>shield. > > >> >>What would you use such a sensor for? The best I've thought of is > >> >>detecting the flow of current in a PCB to find a short circuit. > > >> >You need high spatial resolution for a general-purpose board short > >> >finder. Magnetically, you can do it with a pulsed current source and a > >> >really tiny ferrite-core pickup coil. I do it lately with a DC source > >> >and a thermal imager, so you can *see* the current path. > > >> >John > > >> A microvolt meter makes short finding trivial. Somewhere back in time > >> I posted how I made my own at GenRad in the late '70's > > >> ...Jim Thompson > >> -- > >> | James E.Thompson, CTO | mens | > >> | Analog Innovations, Inc. | et | > >> | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | > >> | Phoenix, Arizona 85048 Skype: Contacts Only | | > >> | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | > >> | E-mail Icon athttp://www.analog-innovations.com| 1962 | > > >> Cranky Old Git With Engineering Mind Faster Than a Speeding Prissy > > >Did you woek at gen rad? > > >I got some questions about someone I knew that worked there in that > >time frame > > I was Analog Guru at GenRad Portable Products Division, Phoenix, from > 1977 to 1987. > > ...Jim Thompson > -- > | James E.Thompson, CTO | mens | > | Analog Innovations, Inc. | et | > | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | > | Phoenix, Arizona 85048 Skype: Contacts Only | | > | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | > | E-mail Icon athttp://www.analog-innovations.com| 1962 | > > Cranky Old Git With Engineering Mind Faster Than a Speeding Prissy My friend worked out of Boston. I think he must have left around 1977 or so (it would have been shortly before going public). He said that he worked there for many years prior to Gen rad going public, and they paid many of their engineers in shares of the company. He was one of the engineers with quite a lot of this stock. There was a stipulation that the stock must be sold back to the company if the employee left the company. Just prior to the company going public, they essentially fired several of these high engineer holders of company stock and forced them to sell at the agreed upon rate back to the company. Some short time later, the company went public and those shares that he had to sell back would have been worth 250K (that is number I think he said it cost him in 1970 something dollars) Have you heard this story?
From: Jim Thompson on 21 Oct 2009 20:38 On Wed, 21 Oct 2009 17:35:15 -0700 (PDT), brent <bulegoge(a)columbus.rr.com> wrote: >On Oct 21, 8:05�pm, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- >Web-Site.com> wrote: >> On Wed, 21 Oct 2009 16:58:33 -0700 (PDT), brent >> >> >> >> <buleg...(a)columbus.rr.com> wrote: >> >On Oct 21, 10:51�am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- >> >Web-Site.com> wrote: >> >> On Wed, 21 Oct 2009 07:37:36 -0700, John Larkin >> >> >> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >> >On Wed, 21 Oct 2009 06:21:02 -0700 (PDT), MooseFET >> >> ><kensm...(a)rahul.net> wrote: >> >> >> >>Imagine you had a sensor that could measure very small magnetic >> >> >>fields. �It measures with a noise floor of about 0.1fT. �Unfortunately >> >> >>the band width is only a few hundred Hz and it only works inside a >> >> >>shield. >> >> >> >>What would you use such a sensor for? �The best I've thought of is >> >> >>detecting the flow of current in a PCB to find a short circuit. >> >> >> >You need high spatial resolution for a general-purpose board short >> >> >finder. Magnetically, you can do it with a pulsed current source and a >> >> >really tiny ferrite-core pickup coil. I do it lately with a DC source >> >> >and a thermal imager, so you can *see* the current path. >> >> >> >John >> >> >> A microvolt meter makes short finding trivial. �Somewhere back in time >> >> I posted how I made my own at GenRad in the late '70's >> >> >> � � � � � � � � � � � � � � � � � � � � ...Jim Thompson >> >> -- >> >> | James E.Thompson, CTO � � � � � � � � � � � � � �| � �mens � � | >> >> | Analog Innovations, Inc. � � � � � � � � � � � � | � � et � � �| >> >> | Analog/Mixed-Signal ASIC's and Discrete Systems �| � �manus � �| >> >> | Phoenix, Arizona �85048 � �Skype: Contacts Only �| � � � � � � | >> >> | Voice:(480)460-2350 �Fax: Available upon request | �Brass Rat �| >> >> | E-mail Icon athttp://www.analog-innovations.com|� �1962 � � | >> >> >> Cranky Old Git With Engineering Mind Faster Than a Speeding Prissy >> >> >Did you woek at gen rad? >> >> >I got some questions about someone I knew that worked there in that >> >time frame >> >> I was Analog Guru at GenRad Portable Products Division, Phoenix, from >> 1977 to 1987. >> >> � � � � � � � � � � � � � � � � � � � � ...Jim Thompson [snip] > > >My friend worked out of Boston. I think he must have left around 1977 >or so (it would have been shortly before going public). He said that >he worked there for many years prior to Gen rad going public, and they >paid many of their engineers in shares of the company. He was one of >the engineers with quite a lot of this stock. There was a stipulation >that the stock must be sold back to the company if the employee left >the company. Just prior to the company going public, they essentially >fired several of these high engineer holders of company stock and >forced them to sell at the agreed upon rate back to the company. Some >short time later, the company went public and those shares that he had >to sell back would have been worth 250K (that is number I think he >said it cost him in 1970 something dollars) > >Have you heard this story? I don't know when they went public. I do know that I lost $40K overnight in the infamous 1984 debacle :-( ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Cranky Old Git With Engineering Mind Faster Than a Speeding Prissy
From: Jim Thompson on 21 Oct 2009 20:41
On Wed, 21 Oct 2009 17:38:58 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com> wrote: >On Wed, 21 Oct 2009 17:35:15 -0700 (PDT), brent ><bulegoge(a)columbus.rr.com> wrote: > >>On Oct 21, 8:05�pm, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- >>Web-Site.com> wrote: >>> On Wed, 21 Oct 2009 16:58:33 -0700 (PDT), brent >>> >>> >>> >>> <buleg...(a)columbus.rr.com> wrote: >>> >On Oct 21, 10:51�am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- >>> >Web-Site.com> wrote: >>> >> On Wed, 21 Oct 2009 07:37:36 -0700, John Larkin >>> >>> >> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >>> >> >On Wed, 21 Oct 2009 06:21:02 -0700 (PDT), MooseFET >>> >> ><kensm...(a)rahul.net> wrote: >>> >>> >> >>Imagine you had a sensor that could measure very small magnetic >>> >> >>fields. �It measures with a noise floor of about 0.1fT. �Unfortunately >>> >> >>the band width is only a few hundred Hz and it only works inside a >>> >> >>shield. >>> >>> >> >>What would you use such a sensor for? �The best I've thought of is >>> >> >>detecting the flow of current in a PCB to find a short circuit. >>> >>> >> >You need high spatial resolution for a general-purpose board short >>> >> >finder. Magnetically, you can do it with a pulsed current source and a >>> >> >really tiny ferrite-core pickup coil. I do it lately with a DC source >>> >> >and a thermal imager, so you can *see* the current path. >>> >>> >> >John >>> >>> >> A microvolt meter makes short finding trivial. �Somewhere back in time >>> >> I posted how I made my own at GenRad in the late '70's >>> >>> >> � � � � � � � � � � � � � � � � � � � � ...Jim Thompson [snip] >>> >>> >Did you woek at gen rad? >>> >>> >I got some questions about someone I knew that worked there in that >>> >time frame >>> >>> I was Analog Guru at GenRad Portable Products Division, Phoenix, from >>> 1977 to 1987. >>> >>> � � � � � � � � � � � � � � � � � � � � ...Jim Thompson >[snip] >> >> >>My friend worked out of Boston. I think he must have left around 1977 >>or so (it would have been shortly before going public). He said that >>he worked there for many years prior to Gen rad going public, and they >>paid many of their engineers in shares of the company. He was one of >>the engineers with quite a lot of this stock. There was a stipulation >>that the stock must be sold back to the company if the employee left >>the company. Just prior to the company going public, they essentially >>fired several of these high engineer holders of company stock and >>forced them to sell at the agreed upon rate back to the company. Some >>short time later, the company went public and those shares that he had >>to sell back would have been worth 250K (that is number I think he >>said it cost him in 1970 something dollars) >> >>Have you heard this story? > >I don't know when they went public. I do know that I lost $40K >overnight in the infamous 1984 debacle :-( > > ...Jim Thompson GenRad upper management had trouble coping with the 20th Century. They also didn't like a upstart division out there in Phoenix, making something different, that wasn't in a wooden box, showing them up by making consistent profits... so they shut us down :-( ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Cranky Old Git With Engineering Mind Faster Than a Speeding Prissy |