Hobby Projects - Insulation tester, LED Circuits, Meters.

Monday, May 15, 2017

Online Museums of Hewlett-Packard

HP Archive  - This site is run by Glenn Robb, an Electrical Engineer and HP aficionado. It's goal is to help others collect, preserve and enjoy vintage HP equipment and literature.

Online Museum of Hewlett-Packard - Ken

"This web site is devoted to the history of test equipment produced by the Hewlett-Packard Company which is now known as Agilent Technologies. I own a huge collection of vintage Hewlett-Packard test equipment, catalogs, equipment manuals, and Hewlett-Packard Journals" -  Kenneth A. Kuhn.

HP's Instrumentation and Technologies Division became Agilent, Recently Keysight a new firm sprang from Agilent as the Heir to the Scopes, Meters, Oscillators and Counters. So in this blog we are relating to Keysight as the continuation of the old HP tradition of Test and Measurement.
(The present hp is a computer company and agilent a health care firm)

Online Museums of Hewlett-Packard

Their first business location in the Santa Clara Valley is the now iconic garage located at 367 Addison Avenue in Palo Alto. Here they manufacture the company's first product, the 200A Audio Oscillator. Disney Studios becomes interested in the 200A and orders eight to be used in the production of their movie, Fantasia.

Keysight Technologies History

"As the company moves into this decade it undergoes a major transformation. In 2013 Agilent Technologies announces that it will split into two separate pure-play measurement companies. The name of the new electronic measurement company is announced later in the year as Keysight Technologies."

The HP Garage is a private museum where the company Hewlett-Packard (HP) was founded. It is located at 367 Addison Avenue in Palo Alto, California. It is considered to be the "Birthplace of Silicon Valley"

HP Memory Project - Vintage Hewlett Packard
"The HP Memory Project is, first of all, a collection of vintage Hewlett-Packard hardware, software, documentation and other technical and marketing materials from HP's early years in the instrumentation and computer industry (beginning in 1939).

Tuesday, May 09, 2017

Microohm Meter with LED Analog Bar

This indicates like LM3914 in dot-mode. It is a drawing i made made to troubleshoot a gadget, around two decades ago. Strangely it had a echo of a design i had made into a 7107 dpm years before that. Now i am scanning all my drawing and notes, useful or not. Clean or with errors. Many Errors = 1 Blunder. Some projects i made have been expensive Blunders. So see them with a skeptic eye, fix them, try them. Thats all for now.

See the Circuit Full Size - Microohm Meter with LED Analog Bar

Microohm Meter with LED Analog Bar

This has a 9V battery power. The 555 spins and a negative voltage for Opamp is created. This is a Low Offset amp of OP37 of Precision Monolithics, Inc PMI an early innovator. This diff-amp amplifies the uV of a 4 wire resistance measurement.

Now the current pump is the 2N2222 you see above the OP37. The FET and 555 do synchronous rectification. The LM324 is the Indicator and Analog to LED Dot-Bar Converter. The probes are Gold Plated, or use solid gold pins if you have them in plenty.

Monday, May 01, 2017

Mikes Optical Timer Counter

"This page is the result of a lot of effort over the past couple years to develop a quality, inexpensive device to test shutters on the classic film cameras that I have been using..." .. Mike

Mikes Optical Timer Counter

Once built, this counter timer/device is easily adapted to a wide variety of applications, simply by construction of a new sensor.  Although designed to be used with photo-transistors, this device can also use relays, transistors and many other kinds of electrical switches as a sensor.

Mikes Optical Timer Counter

Other Projects

Model Railroading, 3 Transistor Audio Preamp for a Dynamic Microphone

Configuration and control of this counter/timer is through a RS232 port. Cable configuration for a usual PC compatible would consist of a null modem cable, with a female connector on the timer/counter end of the cable. The correct cable for a PC or usb to serial adapter with a DB-9 interface is listed in the bill of materials.