GAP/R
George A. Philbrick Researches
Archive
www.PhilbrickArchive.org
last updated:
August 8th, 2008
page started:
February 3rd, 2005
PhilbrickArchive: 560MB:
scans, photos & plots
355 html pages
864 gif
107 pdf
1188 jpg
4 zip
8 other
2540 total files
|
This site is a free non-profit repository of materials from GAP/R George A Philbrick Researches, the company that launched the commercial use of the Operational Amplifier in 1952.
I dedicate this site to the
many engineers that gave the Analog industry its great start with
their state-of-the-art Philbrick products, and by setting new
professional standards, and creating new ways to solve engineering
problems with the application of analog elements. After Philbrick,
these engineers went on to lay the foundations of the analog industry
in new companies like Linear Technology, Analog Devices and National
Semiconductor, among many others. The first commercial Operational amplifier was the K2-W op-amp. It was based on the amplifier used in the Philbrick modular Analog-Computor "black boxes ". That amplifier's basic circuit architecture, in turn, was probably inspired by an earlier amplifier designed by Loebe Julie (Dan Sheingold and Bob Pease, thanks for helping me with this information). The K2-W Operational Amplifier entered the commercial market in 1952, and was last manufactured in 1971 (see Prof. Tom Lee in SSCS News). It performed mathematical Operations in analog computers. Soon after, the K2-W and its successors saw wide application in industry. The Analog Computer was one educational vehicle to familiarize the engineer and the engineering student, with Operational Amplifier techniques. GAP/R also took on a crucial educational leadership role with application guides and tutorials. Doug Coulter contributed this single page account of GAP/R history written by GAP covering 1938 to 1957 (added 3-25-7). Over time, GAP/R was bought and sold, and existed under different names: Philbrick-Nexus, Teledyne Philbrick, Teledyne semiconductor, TelCom Semiconductor and currently Microchip. Walt Jung has published an excellent OPAMP applications handbook on the Analog Devices web site. The whole 970 page book is downloadable in whole, or in separate chapters. Chapter H makes an extensive presentation of the history of the OPAMP and several references are made to Philbrick. The very long list of bibliographic references in the history chapter points to many patents and papers showing circuit topologies contemporary with GAP/R. Walt Kester also included an excellent chapter on the history of Analog-to-Digital converters in his most recent Data Conversion Handbook. Kester also makes frequent historical references throughout the rest of the book. I have now (8-12-7) scanned and uploaded all the Philbrick material I have Please let me know if you find any errors. My email address is listed below. I will continue to upload more material from my own measurements, and from contributions. I also hope to expand the Patent portfolio.
Thank you, to all the kind
contributors that have donated their material to help share Philbrick
history. Jim Williams contributed the lion 's share to my collection.
He lent me a Philbrick binder that took me 3 hours to copy, after
work, and is now scanned on this site! If you would like to contribute to this archive your scanned Philbrick materials, photos of Philbrick gear, your own stories to tell, links to related web sites or your advice, please send me an email.
If you are a Philbrick
alumnus, any Philbrick material contributions or comments are
especially welcome. We are all indebted to your far reaching
contributions to the analog industry.
My email is K2W_at_PhilbrickArchive_dot_org |
Philbrick Hall of Fame
John F. Dowd
Roger Noble
Edward L. Maddox
Bob Malter
Pete Hansen
Bob Calkins
Walter Kern
Arnie Lieberman
John I. Smith
Herb Karas
Ralph Granchelli (Sr.)
Ralph Granchelli Jr.
Jack Cassidy
Frank Goodenough
Dick Randlett
Dennis Santucci
Rocco Sansavero
Dick Stearns
Wayne Norwood
Joe Losciuto
Bernie McDonald
Fred Gratton
Marty Liben
Mike Brown
Jerry Hollister
Bob Mockapetris
Peter Scholl
Emanuel Bediako
Alan Risley is keeping the master data base for Philbrick....
Organizational charts, personnel history, and "The Watchamawcallit ","Feedback","Telescope"
Please help me add to this list by letting me know about other Philbrick alumni.
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The Lightning Empiricist aperiodical publication
"Advocating electronic models, until livelier instrumentalities emerge "
1952-01_v01_No1_The_Lightning_Empiricist 4 gif scans 1.3MB Contributed by Warren Yogi courtesy of the Computer Museum in Mountainview CA.
1956-04_no3_The_Lightning_Empiricist 6 gif scans 1.4MB Contributed by Doug Coulter (added 5-20-7)
1956-10_no5_The_Lightning_Empiricist 4 gif scans 1.0MB Contributed by Doug Coulter (added 5-20-7)
1958-10 No6 The Lightning Empiricist 4 jpeg scans 2.2MB Contributed by Jim Williams
1959-03 No7 The Lightning Empiricist 4 jpeg scans 1.9MB
1963-01 V11 No1 The Lightning Empiricist. 8 jpeg scans 3.6MB contributed by Jim Williams (rescanned 5-20-7, contribution of Doug Coulter)
1963-04 V11 No2 The Lightning Empiricist 8 jpeg scans 3.9MB
1963-07_v11_No3_The_Lightning_Empiricist 10 jpeg scans 4MB . contributed by Jim Williams and 2 gif scans 0.5MB for pages 6 & 7 no longer missing, contributed by Bob Pease
1963-10 V11 No4 The Lightning Empiricist 8 gif scans 2.8MB contributed by Jim Williams
1964-1_V12_No1_The_Lightning_Empiricist 8 gif scans 2.8MB contributed by Jim Williams
1965-07 V13 No1&2 The Lightning Empiricist 16 jpeg scans 4.7MB contributed by Jim Williams
1965-07 V13 No3&4 The Lightning Empiricist. 12 jpeg scans 2.2MB contributed by Jim Williams
1966-07 V14 No1&2 The Lightning Empiricist. 8 jpeg scans 1.8MB contributed by Jim Williams
1969-03 V17 No1 The Lightning Empiricist 12 jpeg scans 1.8MB Contributed by Jim Williams
1969-06 V17 No2 The Lightning Empiricist 12 jpeg scans 4.0MB Contributed by Jim Williams
1969-09 V17 No3 The Lightning Empiricist. 20 jpeg scans 4.4MB contributed by Jim Williams
1970-01 V18 No1 The Lightning Empiricist. includes "angels on a pin" on the last page. 8 jpeg scans 2.1MB contributed by Jim Williams
1971-06 The New Lightning Empiricist. Teledyne-Philbrick. 22 jpeg scans 5.3MB contributed by Jim Williams
A Lightning Empiricist literary supplement 2. June 1969. Preliminary edition.
A Lightning Empiricist literary supplement 3. September 1969. Preliminary edition.
Notes on the design of the P-85 3 gif scans 0.2MB
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Application Briefs
No. D1 December 1, 1959 2 gif scans 0.3MB contributed by Jim Williams. Further contribution by Doug Coulter, with a cleaner scan (3-30-7).
No. D2 April 1, 1960 2 jpeg scans 0.3MB contributed by Jim Williams
No. D3 June 22,1960 2 jpeg scans 0.5MB contributed by Jim Williams
No. D4 February, 1961 4 jpeg scans 1.3MB contributed by Jim Williams
No. D5 April 3, 1963 2 jpeg scans 0.9MB contributed by Jim Williams
No. D6 May 9, 1963 1 jpeg scans 0.5MB contributed by Jim Williams
No. D7 May 17, 1963 2 jpeg scans 1.0MB contributed by Jim Williams
No. D8 August 15, 1963 2 jpeg scans 1.0MB contributed by Jim Williams
No. D9 September 3, 1963 2 jpeg scans 0.7MB contributed by Jim Williams
No._E1_January_7_1966 1 gif scan 0.1MB (added 8-27-6)
No_R1_February_1,_1961 "Practical closed-loop stabilization of solid state operational amplifiers ". This is a classic by Bob Pease at the start of his career. 37 gif scans 3.3MB contributed and scanned by Alan Risley (added 8-5-7)
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Applications Notes
AN-12 Designer's guide to Logarithmic amplifiers August 1973, by Alan Risley 10 gif scans 1.3MB. Contributed and scanned by Alan Risley (added 8-2-7)
AN-21 Designing high speed data acquisition systems April 1976, by Dennis Santucci 10 gif scans 2.5MB. Contributed and scanned by Alan Risley (added 8-3-7)
AN-24 Specifying and testing Analog-to-Digital Converters, July 1976, by R. W. Jacobs 7gif scans 2.6MB Contributed and scanned by Alan Risley (added 8-2-7)
AN-25 Specifying and testing Digital-to-Analog Converters, July 1976, by R. W. Jacobs 7gif scans 2.6MB Contributed and scanned by Alan Risley (added 8-2-7)
AN-30 Specifying and testing Sample-and-Hold amplifiers March 1977 by Robert W. Glines 5 gif scans 0.6MB Contributed and scanned by Alan Risley (added 8-4-7)
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Applications Publications
Article_reprints_from_various_journals.zip Very large file, 40.2MB with 213 pages of article reprints from various journals. This zip file uses standard encryption, and the password is "k2w ", in lower case. This collection of 33 article reprints illustrates the early application of operational amplifiers in analog computers with practical analog simulation examples, and also shows applications for the OPAMP beyond the analog computer, as signal conditioning element, or as a control element in a process control loop. Contributed by Doug Coulter (added 4-20-7)
"A Palimpsest on the Electronic Analog Art Being a collection of reprints of papers & other writings which have been in demand over the past several years ". You can find a descripition of the Palimpsest in the recommended reading section.
A Primer in the art of using operational amplifiers in general utility instrumentation by Charles F. Morrison Jr 1964. Gives a survey of early use of operational amplifiers in chemistry. 1 Zip file containing 104 gif scans 15.6MB This zip file uses standard encryption, and the password is "k2w ", in lower case. Contributed by Dan Sheingold (added 7-28-7)
Analog Computor Techniques applied to industrial instrumentation and control. Part II of notes for a talk given before the IRE-PGEC on January 16 1958, New York City. 8 jpeg scans 1.0MB Contributed by Jim Williams
Analog_computor_techniques_applied_to_industrial_instrumentation_and_Control_PartI and II 29 gIf scans 3.2MB contributed by Doug Coulter.(added 3-25-7)
Applications Manual for PHILBRICK OCTAL PLUG-IN Computing Amplifiers. GAP/R K2 SERIES 1956. 32 gif scans 12.5MB (rescanned 6-7-5) Contributed by Jim Williams
Applications_Manual_for_PHILBRICK_OCTAL_PLUG-IN_Computing_Amplifiers_1956to1961_GAP-R_K2-Series Various versions 44 gif&jpg scans 6.1MB Contributed by Doug Coulter (added 5-20-7)
Typical Operational Amplifier Applications for Modeling, Measuring, Manipulating & Much else. August 1964.1 jpeg scan 0.3MB Contributed by Jim Williams
Applications Manual for Computing Amplifiers for Modeling, Measuring, Manipulating & Much Else. This manual was published in 1965 and continues the work of the earlier application manual during the transition to solid state amplifiers. Copies of this manual still show up on ebay occasionally, and are 100% applicable to modern analog design. Dan Sheingold edited the original publication and wrote a new introduction which is only a 1MB pdf file. The full download is a 75MB pdf file, both at the Analog Devices site. Also see further comments on this publication here.
Reprint No. 18 10 jpeg scans 5.1MB contributed by Jim Williams
New Approaches to the Design of Active Low Pass Filters by Peter D. Hansen ScD, VP 10 jpeg scans 1.5MB contributed by Jim Williams
Analog Methods by Bruce Seddon Vice President. Presented at the twelfth annual symposium Computors in the process industry. New Jersey Section Instrument Society of America, Inc. Reprint no. 27 April 5th 1960. - 13 jpeg scans 2.9MB Contributed by Jim Williams
Capabilities of some Non-linear instrument circuits for Low Level Transients by Bruce Seddon Reprint no. 40. February 1963. - 21 jpeg scans 4.0MB. Contributed by Jim Williams
Electronic Analog Instruments as Tools of Research and Development by George A. Philbrick President of GAP/R Reprint No.35 October 1961. - 8 jpeg scans 2.2MB Contributed by Jim Williams
A promotional photo outlining Philbrick OPAMP History from 1946 to the 1970's, kindly contributed by Alan Risley. 0.4MB
1952_Radio_&_Television_News_Philbrick and Paynter announce partnership 0.8MB (added12-23-5)
Philbrick Amplifier Selector slide rule from ebay auction #6179509106 1 jpg photo 0.1MB
A_Word_of_Common_Sense 1 gif scan 0.1MB (added 8-27-6)
Typical_Operational_Amplifier_Applications_for_Modelling,_Measuring,_Manipulating_and_Much_Else 1 gif scan 0.2MB (added 8-27-6)
Special_Technical_Memorandum_to_all_Engineering_Representatives_by_Bruce_Seddon advises the field on application of the SK2-B and P65, 2gif scans 0.3MB, Contributed by Doug Coulter (added 5-17-7)
Applying Op Amps Article by Alan Risley in "Instruments and control systems", 1973 3 gif scans 0.4MB Contributed and scanned by Alan Risley (added 8-5-7)
1977_Alan_Risley_explains_Philbrick_share_of_the_high_performance_analog_market This interesting interview of Teledyne-Philbrick marketing and sales director Alan Risley outlines the path often taken by analog companies (such as Analogic), that continued to use discrete circuit approaches that combined IC's manufactured by the analog segment of the semiconductor industry, to make a high value product without owning a semiconductor foundry. 5 scans 1.8MB Contributed and scanned by Alan Risley (added 8-2-7)
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Written contributions
Email from Tom Graves 1-29-5
Email exchange with Winfield Hill and Guy Macomb in the sci.electronics.design newsgroup. March 2004. I have since moved all the Philbrick material mentioned in this discussion from WWW.Photodex.com to this site.
Email from Dr. Günter Ritter in Germany 5-3-5 Günter shares his first experience with Philbrick
Email from Karlsnake 5-12-5 Karl shares his knowledge of tubes used by Philbrick
Email from Vito Bronzo in Italy 5-29-5 Vito shows Tung-sol 12AX7 used by Philbrick.
Email exchange with Bob Pease and Steven Weber from Berlin NH-USA 10-20-5. Steven used solid state Philbrick modules to make an audio power amp in college.
Email from Chuck Maher from Mustang OK-USA. Chuck remembers his experience with Philbrick (analog) computers. (Added 3-22-6)
Early history of the use of Philbrick op amps in chemical instrumentation in the words of one of the first users of opamps in Chemistry at the University of Washington in the early 1950's, Jack Harrar gives a fascinating account of how the OPAMP caught on, and how Philbrick was a crucial link in the universal adoption of the OPAMP. Thank you Jack Harrar, for you very thoughtful contribution. (Added 1-5-7, updated 1-11-7)
Reminiscences from Dan Sheingold about early use of OPAMP's in Academia (added 1-11-7)
A note about Philbrick users father and son David Coulter and Doug Coulter (added 5-20-7)
A very interesting account by Analog Computer designer Ed Lyon about his design of analog flight simulators, such as the "F-86D single-seat interceptor aircraft ". This very talented engineer contributes regularly to Radio Age, the newsletter of the Mid-Atlantic Antique Radio Club. (added 8-7-7)
1961: It was a very good year. Bob Pease comments on project activity at Philbrick. Contributed by Bob Pease (added 12-4-7)
Excelence in technical writing: a Philbrick Legacy. Well known writers Dan Sheingold and Bob Pease descend from this Philbrick legacy. A recent email exchange was initiated by William Sommerwerck, and points this out. (added 3-6-8)
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Catalogs and price lists
1951 Catalog & Manual on GAP/R high speed all-electronic analog computors for research and design 18 gif scans 2.1MB Contributed by Dan Sheingold
1958_July_15th_Domestic_Price_List 1jpg scan 0.4MB contributed by Doug Coulter (added 5-20-7)
1958_several_ads_in_Electrical_Design_News_magazine several ads show how Philbrick marketed it's products in a leading design magazine. 1 pdf file 0.4MB Contributed by Achim Dassow in Switzerland (added 2-27-7)
1958_Cover_letter_by_Dan_Sheingold_sent_to_David_L_Coulter_with_catalog These 2 scans mark the start of a major contribution of 512 pages of Philbrick material by Doug Coulter, David L Coulter's son. The 512 scan names start with DC and a 3 digit sequence number. 2 scans 0.5MB (added 3-25-7)
1959_April_1st_Domestic_Price_List 1 gif scan 0.2MB contributed by Doug Coulter (added 5-20-7)
1959_September_1st_Domestic_Price_List 1 gif scan 0.2MB contributed by Doug Coulter (added 5-20-7)
1959_The_Analog_way_is_the_model_way Promotional color brochure. 4 jpeg scans 1.2MB
1960's Philbrick Catalog 16 jpeg scans 4.9MB
1963 Price List July 1, 1 jpg scan 0.4MB
1963 August Product Table with prices 1 jpg scans 1.5MB 2 additional scans Contributed and scanned by Ad Sprenkels (added 5-10-8)
1965,May Price List 1 jpg scan 0.4MB Contributed by Jim Williams
1965A directory on how to do business with Philbrick and services offered, February . 6 jpeg scans 2.4MB Contributed by Jim Williams
1966_Dec_1st_price_List 4 gif scans 0.4MB (added 8-27-6)
1966_OPAMP_Bulletin_6111 6 gif scans 1.0MB (added 8-27-6)
1968_pricelist_june 2 jpg scans 0.6MB Contributed and scanned by Ad Sprenkels (added 5-10-8)
1968_Russian_catalog_Moscow_show See the lightning empiricist with show on front page. 24 gif scans 1.4MB contributed and scanned by Alan Risley (added 8-4-7)
sterling_company Representated Philbrick-Nexus. includes two price lists for 1968 1969. 1 jpg 2gif scans contributed and scanned by Ad Sprankels (added 5-11-8)
1969 OPAMP wall chart 8 jpg scans 2.0MB contributed and scanned by Alan Risley (added 8-4-7)
1969-70_philbrick-nexus_catalog 30 jpg scans 6.4MB contributed and scanned by Ad Sprankels (added 5-11-8)
philbrick-nexus_research_operational_amplifiers 29 jpg scans 6.4MB contributed and scanned by Ad Sprankels (added 5-11-8)
introduction_to_operational_amplifier_technology 13 gif scans 1.2MB contributed and scanned by Ad Sprankels (added 5-11-8)
1970_Bussiness_reply_card_January 2jpg scans 0.1MB
1971 Philbrick enters monolythic market with improved 741 OPAMP. 2 jpg scans 0.7MB contributed and scanned by Alan Risley (added 8-4-7)
1972 Data Converter wall chart 8 scans 2.0MB contributed and scanned by Alan Risley (added 8-4-7)
1976 Teledyne-Philbrick Product guide The complete catalog has 192 pages. The product summaries are uploaded here in 9 gif scans 3.6MB contributed by Eric Tauecchio in the Netherlands
1970's Solid_State_Amplifier_Catalog 29gif scans 7.3MB contributed by Eric Tauecchio in the Netherlands
1970's OPAMP guide: cover and one page 2 jpg scans 0.3MB contributed by Eric Tauecchio in the Netherlands
1970's OP Amp Seminar in Germany cover pages 2 gif scans 160k contributed and scanned by Alan Risley (added 8-5-7)
1982 List of equivalents for obsolete models in the catalog 1 jpg scan 0.1MB
1982_Teledyne-Philbrick_OPAMPS_and_Data_Converters The complete catalog has about 200 pages. The product summaries ahead of each section and the covers are uploaded in 21 gif scans 6.4MB. Please see the next item for indivudual data sheets added subsquently.
1982_Teledyne_Philbrick_full_catalog in 77 pdf files, graciously contributed by Sharon Fletcher of Teledyne Microelectronic Technologies. Philbrick was once a division of Teledyne. Sharon still gets requests for Philbrick product information about once a week. 77 pdf files totaling 27.2MB (added 6-16-6)
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Power supplies
R-100A_Compound_Regulated_Dual_Power_Supply 4 scans 0.8MB Contributed by Doug Coulter (3-25-7)
R100-B R300 R600 +/-300V Power supplies 27 jpeg scans 4.9MB (updated with missing page5 5-8-2008 contributed by Achim Dassow)
R100_B_interior_Photos 6jpg photos of interior 0.6MB Contributed by Achim Dassow (5-4-8)
RK-200_Compound_Regulated_Dual_Power_Supply 2 jpg scans 0.3MB Contributed by Doug Coulter (3-25-7)
R300 +/-300V power supply 10 gif scans 2.5MB
SR-400_Tracking_Type_Super-Regulated_Dual_Power_Supply 12 jpg gif scans Contributed by Doug Coulter (added 3-25-7)
R500 +/-300V 500mA power supply interior photos 11 images 1.1MB Contributed by Ron Roscoe
Models PR-150 and PR-150C Compound Regulated dual +/-15V Power supplies 4jpeg scans 0.6MB
Models PR-30 and PR-30C Compound Regulated dual +/-15V Power supplies 4 jpeg scans 0.7MB
Model PR-300 Compound regulated dual +/-15V Power supply 1 jpeg photo 0.1MB
Model 6033 was available as an open chassis supply, and it appears that if had similar characteristics to the PR300.
2101 potted modular power +/-15V 100mA 3-wire DC regulator According to Jim Williams, who consulted at Philbrick in the 70's, these potted power supply modules were made by Computer Products and resold by Philbrick. 4 gif scans and one photo 1MB contributed by Eric Tauecchio in the Netherlands
2103-04-05_dc_regulator_preliminary 0.3MB Contributed and scanned by Ad Sprenkels (added 5-11-8)
2202_dual_power_supply_preliminary 2 gif scans Contributed and scanned by Ad Sprenkels (added 5-11-8)
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Operational Manifolds
Model 6009 Operational Manifold Preliminary data 3 jpeg scans 1.0MB
Model K7-A6 Operational Manifold with six USA-3 Universal Stabilized Operational Amplifiers, and two slightly modified USA-3's in the integral power supply regulator. Also called the "ISIS"
Model K7-A10 Stabilized Operational Manifold 17 jpeg scans 10.7MB
Model MK Operational Fourfold 2 jpeg scans 0.6MB Contributed by Jim Williams and updated with better scans of Doug Coulter's material on 3-25-7
Model HK Operational Manifold 2 jpeg scans 1.1MB Contributed by Jim Williams
Model HKR_Operational_Manifold 4 jpg gif scans 0.9MB Contributed by Doug Coulter (3-25-7)
Model SK5-H High Performance Fivefold. Tentative Instructional Manual 24 jpeg scans 9.1MB Contributed by Jim Williams
Model SK5-U Alignment and Troubleshooting 8 jpeg scans 2.1MB Contributed by Jim Williams
Model SK5-F Arbitrary Function Component 2 jpeg scans 0.4MB Contributed by Jim Williams
Model SK5-R Relay Control Component. Tentative instruction manual. 15 jpeg scans 1.7MB Contributed by Jim Williams
Model SK5-M Multiplier Divider. Short form preliminary data 4 jpeg scans 0.5MB
Model MP Self Powered 4 amplifier Operational Manifold. 4 jpeg scans 1.6MB Contributed by Jim Williams
Accessory kits with precision resistors capacitors, diodes and adapters for use with Philbrick manifolds. 1 gif Scanned and Contributed by Ad Sprenkels (added 2-22-8)
Model MP Photograph 1 jpeg scan Contributed by John Anstreicher
Model RP-4-68_operational_manifold 4jpg scans 0.7MB Contributed and scanned by Ad Sprenkels (added 5-10-8)
Models_RP_and_MP_operational_manifolds 6jpg scans 1.7MB Contributed and scanned by Ad Sprenkels (added 5-10-8)
Philbrick Multi-Channel Calibrated Display System for Analog Computor Readout 1 jpeg scan 0.3MB Contributed by Jim Williams
Accessories for the Philbrick Multi-Channel Calibrated Display System 5934 1 jpeg scan 0.2MB Contributed by Jim Williams
Custom_Manifold with Grass instruments 3 jpg photos 0.2MB (added 6-4-6) contributed by Doug Coulter
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Mathematical operators
K3 series components: Adding, Bounding, Coefficient,Differentiating, Augmenting_Differentiator, backlash, Integrating, Augmenting, Unit_Lag, Absolute_Value, Inert_Zone. These were known as "The little black boxes ", and were the first mass application of the K2-W tube differential Operational amplifier. 22 gif scans 4.0MB Contributed by Doug Coulter (3-28-7)
Passive_Operational_Plugins dated from 1956. 4 gif scans 0.5MB Contributed by Doug Coulter (3-30-7)
Model_CS-2_Central_Signal_Component. "Provides 5 principal signal outputs: Ramp Sweep Step Clamp and DC Volts. " 8 scans 1.7MB Contributed by Doug Coulter (3-28-7)
Model_CRM_&_CR_Central_Response_Component Plot one to five curves on electronic graph paper on CRT. 8 scans 1.5MB Contributed by Doug Coulter (3-28-7)
Model_5934_Philbrick_multi-channel_calibrated_display_system 15 jpg scans 3.1MB Contributed by Doug Coulter (3-30-7)
Model FF Arbitrary Function Component 8 gif scans 1.5MB. Contributed by Jeff Mallins.
Model MUDV Multiplex multiplier divider 6 gif scans 1.1MB Contributed by Jeff Mallins
K5-4_Universal_Linear_Operator 13 jpg and gif scans 2.8MB Contributed by Doug Coulter (added 3-25-7)
Model K5M Multiplier Divider 2 gif scans 0.3MB Contributed by Jim Williams additional advertising page contributed by Doug Coulter(3-30-7)
K2-G_Triangular_Wave_Generator_Preliminary_Data 4 gif scans 0.3MB Contributed by Doug Coulter (added 3-25-7)
F2V_Function_of_Two_Variables 17 gif scans 2.9MB Contributed by Doug Coulter (3-25-7)
Dual Logarithmic Transconductors Models PL1-N, PL1-P, PPL1-N, PPL1-P. Tentative data 10-14-64. 4 jpeg scans 1.3MB Contributed by Jim Williams
Square & Root with the New Philbrick Quadratic Transconductor PSQ-N 1 jpeg scan 0.2MB Contributed by Jim Williams
Model PSQ-P & -N quadratic transconductor. Tentative technical data. Revised 9-15-64 6 jpeg scans 1.0MB Contributed by Jim Williams
4357 4358 tranistorized potted module log operators 2 gif scans 0.4MB contributed by Eric Tauecchio in the Netherlands
Philbrick_Computer_Components_K3-K4_series from "Analog Computer Techniques " by Clarence Johnson 8jpg scans 2.4MB
PSQN Quadratic transconductor exterior 2 jpg 0.2MB contributed by Ad Sprenkels in the Netherlands on 1-5-6
SPDIF_difference_amplifier - Instrumentation amplifier with jumper programmable gains. 1gif hand traced schematic, 9 jpg interior photos 1.0MB. This module was graciously lent by Dan Sheingold. (added 3-26-6) (updated 9-26-7)
4350-4351_log_modules 8scans 1.9MB Contributed and scanned by Ad Sprenkels (added 5-12-8)
4350_log_operator photo 1jpg photo 0.1MB
4352_Vector_Magnitude_operator |X+jY| Squares inputs X and Y, sums them, takes the square root and averages. 2gif scans from 1976 product guide. 2photos contributed by Bill Courtright (added 3-26-6)
4450_four_quadrant_multiplier 2gif scans 0.2MB Contributed and scanned by Ad Sprenkels (added 5-11-8)
4850_gated_opamp_preliminary 1gif scans 0.2MB Contributed and scanned by Ad Sprenkels (added 5-11-8)
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Testers
Philbrick 5102 opamp tester interior views 11 jpg images 1MB
5102_ic_opamp_tester_pagina 4jpg scans 0.8MB Contributed and scanned by Ad Sprenkels (added 5-11-8)
Teledyne Philbrick 5107 opamp tester 18 jpg images 5.4MB Contributed by Shingo Sobugawa
4100_dc_millivoltmeter 4jpg scans 0.8MB Contributed and scanned by Ad Sprenkels (added 5-11-8)
4101_hyperlog_dc_voltmeter 4jpg scans 0.8MB Contributed and scanned by Ad Sprenkels (added 5-11-8)
4352_average_rms_vector_module 4jpg scans 0.6MB Contributed and scanned by Ad Sprenkels (added 5-11-8)
5100_dc_log_ratio_meter_pagina 4jpg scans 0.6MB Contributed and scanned by Ad Sprenkels (added 5-11-8)
5101_dc_log_null_meter_pagina 4jpg scans 0.7MB Contributed and scanned by Ad Sprenkels (added 5-11-8)
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Tube Operational Amplifiers
K2-UX Operational Amplifier module . This module was designed by George Philbrick circa 1946-47, and is part of Philbrick alumnus Alan Risley's collection. 2jpg photos 0.1MB Contributed by Alan Risley
Philbrick_Operational_Amplifiers_2_Lines_to_chose_from An overview of the Philbrick tube opamp line 2 jpg scans 0.6MB Contributed by Doug Coulter(3-30-7)
K2-W Operational Amplifier (early version) 2 jpg scans 0.6MB Contributed by Jim Williams
K2-W Operational Amplifier (later version) 2 gif scans 0.2MB Contributed by Bob Pease
K2-W_OPAMP_(additional_data_sheet_versions) 4 gif scans 0.8MB Contributed by Doug Coulter (added 3-25-7)
K2-WJ Operational Amplifier three different versions of the data sheet. 6 scans 0.8MB Contributed by Jim Williams and Doug Coulter(3-30-7)
K2-W second Source: Embree Photos of interior and my measurement results. 10 jpg & 2 gif 0.6MB (added 12-3-5)
K2-YJ Rugged Operational Amplifier two versions of the data sheet. 4 scans 1.1MB Contributed by Jim Williams and Doug Coulter(3-30-7).
K2-X_+-100V_EXperimental_OPAMP 2 gif scans 0.5MB Contributed by Doug Coulter (added 3-25-7)
K2-XA Operational Amplifier 2 data sheet versions. Contrast this very kludgey design, with a transistor hiding in the shell, with the supremely elegant K2-YJ, that out performs it with less circuitry. See the next item for Bob Pease's account of the evolution of the K2-XA kludge. 4 scans 0.7MB Contributed by Bob Pease and Doug Coulter(3-30-7)
K2-XA_exterior photos 4jpg photos 0.5MB Contributed by Achim Dassow (added 8-4-8)
K2-X to K2-XA evolution by Bob Pease 3jpg scans 1.2MB Contributed by Bob Pease. Also check Bob's article What's all this "Selective Fit" Stuff, Anyhow? and Bob's Mailbox
K2-SR Operational Amplifier for R100-A power supply 1 gif schematic and 6 jpg photos 1.1MB. The SR means "Super Regulator " amplifier. There was an earlier version called the K2-R. (Dan Sheingold, thanks for the info)
K2-SR Super Regulating amplifier module used in the R-100A power supply and some of the older tube supplies. 1gif scan Contributed and scanned by Ad Sprenkels (added 5-11-8)
K2-R Predecessor to the K2-SR, the K2-R was used in some of the older tube supplies. 2 Xray slides Contributed by Dr Miltiades Karamechedis (added 7-19-8)
SK2-V Differential Operational Amplifier data sheet two versions of the data sheet. 4 scans 1.6MB Contributed by Jim Williams and Doug Coulter(3-30-7)
SK2-V _Differential Operational Amplifier_interior 23 jpg photos 5.0MB (added 2-11-6)
SK2-V Original Schematic and application notes 2 gif scans 0.6MB (added 2-25-6)
UPA-2 Utility Packaged Amplifier from 1959 16 scans Contributed by Doug Coulter (added 5-17-7)
UPA-2 Utility Packaged Amplifier from 1965 8 jpg scans 1.9MB Contributed by Jim Williams
UPA-2_Utility_Packaged_Amplifier_tentative_data 16 jpg and gif scans Contributed by Doug Coulter (updated 3-25-7)
USA-3 Universal Stabilized Amplifier 5 jpg scans 1.5MB Contributed by Jim Williams
USA-3_Universal_Stabilized_Amplifier 2 scans 0.5MB Contributed by Doug Coulter (added 5-17-7)
USA-3-M3_modular_enclosure 2 scans 0.2MB Contributed by Doug Coulter (added 3-25-7)
USA-3 K2-W K2-P close-up views 14 jpg images 0.4MB contributed by Nicholas Kertesz
USA-4J Universal Stabilized Amplifier 2 jpg scans 1MB Contributed by Jim Williams
USA-4J Universal Stabilized Amplifier 3 jpg Photos 1MB Contributed by Alan Douglas (added 2-22-8)
K2-PA_SK2-B_K2-W grouping of amplifiers could be combined with DC stabilization from K2-PA of the main opamp K2-W, and with boosted output drive capability provided by SK2-B. 1 jpg photo contributed by Max Artusy (added 3-28-8)
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My measurements of Philbrick Tube Amplifiers
K2-W_serial_#95377 and #12090 4 jpg Photos and 1 gif 0.1MB
A comparison of open loop gain sweeps for K2-W, K2-XA and SK2-V amplifiers 3gif plots 0.1MB
Replacing the 12AX7 in the K2-W with other tubes 8 gif plots 7 jpg Photos 4 pdf data sheets 2.2MB (updated 1-1-6)
Embree model C-50-BP equivalent to K2-W 10 jpg & 2 gif 0.6MB (added 12-3-5)
All the following SK2-V measurements have been done during active correspondence with Bob Pease. His advice has been invaluable.
SK2-V_hand_traced_schematic with DC voltage and DC gain measurements. Tube parameters are estimated. Includes my comments for an improved K2-W design. 1gif 0.1MB (added 2-12-6) (updated 2-14-6)
SK2-V DC voltage sweeps for several brands of 12AU7 with individual adjustment of positive feedback resistance between the cathodes of the 12AU7. 8 gif plots 0.2MB (added 2-25-6)
SK2-V Tube curve tracings from serial #008059 pdf 1.9MB (added 2-26-6)
SK2-X_my_experimental_version_of_SK2-V as an alternative to the K2-X and K2-XA. 1 gif & 2 jpg 0.3MB (added 2-25-6)
SK2-X my experimental version of SK2-V input DC sweep with gain of -20 for supply voltages ranging from +/-300V to +/-25V 1 pdf 0.1MB (added 3-2-6)
SK2-V input DC sweep with gain of -20 for supply voltages ranging from +/-300V to +/-25V 18 gif plots 0.4MB (added 3-20-6)
SK2-V DC offset with inputs grounded in an inverting gain of -20x. Rf=2Meg Ri=100k, 1Gif 0.1Mb(added 3-23-6)
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Tube Stabilizing Amplifiers
K2-PA and K2-P Stabilizing Amplifiers 2 jpg scans 0.4MB Contributed by Jim Williams
K2-PA_Stabilizing Amplifier exterior photos 4jpg photos 0.5MB Contributed by Achim Dassow (added 8-4-8)
K2-PJ Stabilizing Amplifier 2 jpg scans 0.4MB Contributed by Jim Williams
SK2-P Stabilizing Amplifier tentative technical data 2jpg scans 0.3MB Contributed by Jim Williams
SK2-P_Stabilizing_Amplifier Interior photos 8jpg photos 1.3MB Contributed by Achim Dassow (added 8-4-8)
CHOPPERS Airpax 175 and 660 1 jgp photo 0.1MB
6104 Modulator amplifier variant of the K2-P Stabilizing amplifier. The 6104 ommits the output filter. 1 gif scan and 2 jpg photos (0.2MB) Contributed by Bob Pease and Bo Lojek (added 11-30-7, 12-2-7).
Bob Pease shows how to turn an K2-P into a 6104 (added 12-8-7)
Bob Pease shares his experience with choppers (added 12-4-7)
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Tube Booster Amplifiers
K2-B Booster Amplifier 2 jpg scans 0.5MB
K2-BJ Booster Amplifier Tentative Data. 2 gif scans 0.7MB Contributed by Jim Williams
K2-B1_Booster-Follower 2 gif scans 0.3MB Contributed by Doug Coulter (added 3-25-7)
SK2-B Booster Amplifier tentative technical data 6 jpg scans 0.8MB Contributed by Jim Williams
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Transistor Operational Amplifiers
Philbrick-Nexus_Discrete_Amplifiers one chart in 3 gif scans 0.3MB (added 8-27-6)
Philbrick-Nexus_Hybrid_Amplifiers one chart in 3 gif scans 0.3MB (added 8-27-6)
SP102 High Impedance Differential Operational Amplifier with a parametric varactor amplifier architecture. This a late 1960's version of the original late 1950's P2, but with a greatly extended output swing to +/-100V, and all silicon design. 6 gif scans 0.6MB (added 8-29-6)
SP102_exterior Differential Operational Amplifier 2 jpg photos contributed by Ad Sprenkels in the Netherlands on 1-5-6
SP102_interior Differential Operational Amplifier 21 jpg photos contributed by Jim Williams. (added 7-11-7)
Series_2_Parametric_DC_OPAMPS 4 scans (added 8-27-6)
SP2A High Impedance Differential Operational Amplifier. Tentative characteristics. 4 gif images 3.3MB Contributed by Jim Williams.
P2 Differential Operational Parametric Amplifier 4 jpg scans 0.7MB
P2 Differential Operational Parametric Amplifier 2 jpg scans 0.7MB with EEM file system reference
P2_and_applications 6 gif scans 1.1MB
P2 internal views 2 jpg images 0.5MB
P2A Differential Operational Amplifier. Preliminary Technical Data. April 1st,1965. 4 gif images 0.7MB Contributed by Jim Williams
P2A_by_Bob_Pease_exterior 9 jpg photos 0.8MB contributed by Ad Sprenkels in the Netherlands on 1-5-6
P12Q_&_PP12Q_Battery_powered_OPAMP 2 gif scans 0.2MB (added 8-28-6)
P18Q_&_PP18Q_Battery_powered_OPAMP 2 gif scans 0.3MB (added 8-28-6)
P25A Tentative characteristics. December 17th 1964. 1 gif images 0.2MB Contributed by Jim Williams
PP25A Tentative characteristics. 2 gif images 0.2MB Contributed by Jim Williams
PP25AU potted Differential Operational Amplifer view 1 jpg image 0.1MB contributed by Eric Tauecchio in the Netherlands
P25AH fet opamp 2 gif scans 0.3MB (added 8-28-6)
Q25AH Hybrid opamp 2 gif scans 0.2MB (added 8-28-6)
P35A Differential Operational Amplifier. Tentative characteristics. 2 gif images 0.4MB Contributed by Jim Williams
PP35A Differential Operational Amplifier. 2 gif images 0.4MB Contributed by Jim Williams
P45A Differential Operational Amplifier. Tentative Data. 2 gif images 0.4MB Contributed by Jim Williams
P45AL Differential Operational Amplifier with High Output Current. Tentative Characteristics. 2 gif images 0.4MB Contributed by Jim Williams
P45AL_High_Current_tentative 2 gif scans (added 8-29-6)
P45A_exterior 2 jpg photos 0.2MB contributed by Ad Sprenkels in the Netherlands on 1-5-6
PP45U potted Differential Amplifier views 2 jpg images 0.1MB contributed by Eric Tauecchio in the Netherlands
PP45L_Large_Output_Current_OPAMP 2 gif scans 0.3MB (added 8-28-6)
P45AL_High_Current_OPAMP 2 gif scans 0.2MB (added 8-28-6)
PP45_tentative 2 gif 0.5MB (added 8-28-6)
PP45LU economy grade opamp 2 gif scans 0.3MB (added 8-29-6)
PP45U_Ultra_Wideband economy grade opamp 2 gif scans 0.3MB (added 8-29-6)
P55 Differential Operational Amplifier internal views 3 jpg images 0.3MB
P55A All Silicon Utility Operational Amplifier.6 gif images 1.2MB Contributed by Jim Williams
PP55A All Silicon Solid State Differential Operational Amplifier. 2 gif images 0.5MB Contributed by Jim Williams
P55A_tentative 4 gif scans 0.4MB (added 8-28-6)
PP55A 2 gif scans (added 8-26-6)
P65A Differential Operational Amplifier 2 gif scans 1.3MB Contributed by Jim Williams
PP65A All Silicon Solid State Differential Operational Amplifier. 2 gif images 0.3MB Contributed by Jim Williams
PP65AU Differential Operational Amplifier potted module 2 gif Data Sheet scans and 2 jpg Photos 0.7MB Contributed by Shingo Sobugawa
P65AU and PP65AU Utility grade economical all-silicon operational amplifiers. 2 gif scans 0.2MB Contributed by Jim Williams
PP65AH All Solid State Differential Operational Amplifier. 2 gif scans 0.3MB Contributed by Jim Williams
P65&P55_schematic_&_kitting_as_recalled_from_memory_by_Bob_Pease in 2006. Includes details of the kitting for these opamps, Bob's cleaned up schematic and the draft tracing version. 4 gif scans 0.5MB Contributed by Bob Pease (added 12-4-6)
PP65AHU potted Differential Operational Amplifer view 1 jpg image 0.1MB contributed by Eric Tauecchio in the Netherlands
P65AHU_exterior metal case 2 jpg photos 0.2MB contributed by Ad Sprenkels in the Netherlands on 1-5-6
P65AU_exterior metal case with socket 4 jpg photos 0.4MB contributed by Ad Sprenkels in the Netherlands on 1-5-6
P65_Preliminary_data includes applications for electrometer amplifier and summing comparator 11 scans 1.8MB Contributed by Doug Coulter (added 5-17-7)
SP656 exterior 2 jpg photos 0.2MB contributed by Ad Sprenkels in the Netherlands on 1-5-6
P75A Differential Operational Amplifier. 2 gif scans 0.5MB Contributed by Jim Williams
PP75A All Silicon Solid State Differential Operational Amplifier. 2 gif scans 0.3MB Contributed by Jim Williams
Series85 solid state opamps 4 jpg&gif scans 1.0MB (added 8-29-6)
P85A Differential Operational Amplifier.2 gif scans 0.3MB Contributed by Jim Williams
PP85A All Silicon Solid State Differential Operational Amplifier. 2 gif scans 0.3MB Contributed by Jim Williams
P85AU metal case in shipping box 9 jpg photos 1.4MB Contributed by Michel Vanden Broeck from Montreal (added 1-1-6)
Q85AH Hybrid High Performance Differential OPAMP 2 gif scans 0.2MB (added 8-29-6)
P85AH High Performance Differential OPAMP 2 gif scans 0.4MB (added 8-29-6)
1006 Micropower FET OPAMP 4jpg scans 1MB Contributed and scanned by Ad Sprenkels (added 5-10-8)
1008 FET OPAMP drives +/-30mA 4jpg scans 0.7MB Contributed and scanned by Ad Sprenkels (added 5-10-8)
1009 FET OPAMP 3uVrms Noise & 5pA bias 4jpg scans 0.8MB Contributed and scanned by Ad Sprenkels (added 5-10-8)
1011 Medium Speed FET OPAMP 4gif scans 0.7MB Contributed and scanned by Ad Sprenkels (added 5-10-8)
1016 Fast High Power OPAMP 3 jpg scans 0.7MB Contributed and scanned by Ad Sprenkels (added 5-10-8)
1021_1023_1026_High Performance FET OPAMP 2 gif scans 0.3MB as requested by Bill Courtright
1402/01/02 Microcircuit FET OPAMP 1 jpg scan 0.3MB Contributed and scanned by Ad Sprenkels (added 5-10-8)
Photo of early IC OPAMP 1 jpeg scan 0.1MB Contributed by Alan Risley.
Q3-A1P_Stabilized_Amplifier "A Philbrick Universal Operational Module. " 8 gif scans 1.2MB (added 8-29-6)
Q3-A2P_Differential_amplifier "A Philbrick Universal Operational Module. " 8 gif scans 1.1MB (added 8-29-6)
Notes: most Philbrick solid state opamps will not function without the external offset trim resistor. The PP prefix means potted module. The P prefix means metal case module.
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Transistor Booster Amplifiers
P5 Current Booster Amplifier 2 gif scans 0.5MB. Contributed by Jim Williams
P66A High Performance Booster Follower.2 gif scans 0.3MB Contributed by Jim Williams
PP66A and PP66 High Performance Booster Followers. 2 gif scans 0.2MB Contributed by Jim Williams
6154-25. 25-Volt Booster Amplifier. Tentative Characteristics. 2 gif scans 0.2MB Contributed by Jim Williams
6154-100/10 Booster Amplifier. Tentative technical Data. 2 gif scans 0.2MB Contributed by Jim Williams
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Transistor Stabilized Amplifiers
SP456 High Speed Universal Stabilized Amplifier. 6 gif scans 0.9MB Contributed by Jim Williams
SP-656_Universal_Stabilized_Amplifier 6 gif scans 0.6MB (added 8-27-6)
SP65A Universal Stabilized Amplifier. Tentative characteristics. 6 gif scans 0.9MB Contributed by Jim Williams
1700 CHOPPER stabilized amplifier 1 jpg scan 0.3MB Contributed and scanned by Ad Sprenkels (added 5-10-8)
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Data Converters
4707_Teledyne-Philbrick_Voltage-to-Frequency converter 6 gif scans 0.8MB from 1982 catalog (added 1-31-6) requested by David Forbes
4130_Teledyne-Philbrick_ADC_series 1jpg 5gif 0.6MB from 1976 catalog (added 3-19-6). jpg Contributed by Ruud Waij from the Netherlands.
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Photos from EBAY auctions
Philbrick Catalog #2779670408 1-16-4
Model 6009 Operational Manifold #5149576648 closed 12-24-4
Dual power supply with 2 Philbrick op amps #5716639081 closed 8-29-4
R100A dual 300V 100mA power supply with K2-SR opamps #5738787584 closed 12-21-4
R100B dual 300V 100mA power supply
R500 dual 300V 500mA power supply #3815453186
K2-W shells #5742629394 closed 1-13-5
K2-X K2-X Op Amp Airpax A-550 Chopper
K2-X_and_K2-P with 172 chopper detail_#5180480366
K2P-P #5158876478 closed 1-20-5
SK2-B K2-P K2-W in partial boxes
PP65AU New Old Stock #3866571761 closed 1-5-5
P2 pair of units #3855086412 closed 11-26-4
K2P_with_box_#5161291412_closed 2-5-5
K2-W and K2-P from Grass Instruments polygraph machineebay auction #5745254649
P2_and_6033C_supply_in_instrument from ebay seller riatla
K2-B1_ebay_8725173837 Tube Buffer amp 5 JPG Photos 0.3MB added 1-5-6
P5_exterior solid state buffer amplifier 2.JPG Photos 0.1MB added 1-5-6
Palimpsest_8741199317 (description in recommended reading) 5 jpg photos 0.3MB added 1-5-6
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Related Patents
Chopper stabilizer US2684999 E. A. Goldberg et al July 27th 1954, 1 pdf 0.4MB
3,562,660 (Improved differential amplifier; 6628.3) by Robert A. Pease 1pdF 0.3MB
3,668,541 - Base current Compensation. (P85C) by Robert A. Pease 1pdF 0.4MB
3,746,968 - V-to-F Converter (Philbrick 4701) by Robert A. Pease 1pdF 0.4MB
3,868,857 - Dosimeter for Audio Stress - ( by Robert A. Pease with Ed Maddox). 1pdF 0.8MB
3,995,304 - Quad Monolithic Bit Switch (Philbrick part No. 55515505) by Robert A. Pease 1pdf 0.4MB - This was not sold separately, but was used in 1975-era DACs and ADCs.
(Bob Pease, thanks for contributing your list of patents at Philbrick!)
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A search at the European Patent Office site listed the following patents by George A. Philbrick (The US patent office site does not offer searches before 1976):
US2360889A1_Controller.pdf (2.9MB) by George A. Philbrick (added 12-5-5)
US2445335A1_Altitude_and_rate_of_change_measuring_device_and_control_for_aircraft.pdf (1.4MB) by George A. Philbrick (added 12-5-5)
US2503213A1_process_and_control_analyser.pdf network.pdf(1.6MB) by George A. Philbrick (added 12-5-5)
US2730679A1_delayed_recovery_electric_filter_ The circuit in this patent provides very clean time response of transients, outperforming a simple AC coupling network. This circuit with 3 resistors and 3 capacitors also has the interesting property of exhibiting voltage gain of 1.2 over a range of frequencies. (0.4MB) by George A. Philbrick (added 12-5-5)
US2783769A1_combined_balanced_pressure_regulator_and_relief_valve.pdf (1.4MB) by George A. Philbrick (added 12-5-5)
US2935260A1_analog_multiplier.pdf (0.5MB) by George A. Philbrick (added 12-5-5)
US3019983A1_multiplier.pdf (1.1MB) by George A. Philbrick (added 12-5-5)
GB1155901A _improvements_to_electronic_amplifiers.pdf (0.4MB) by George A. Philbrick (added 12-5-5)
US3405366 Electronic (Parametric) Amplifier pdf (0.3MB) relates to P2 and P2A by George A. Philbrick. contributed by Ad Sprenkels in the Netherlands on 1-17-6
US3373293 Temperature compensated Function generating circuit pdf (0.3MB). Break points extablished by diodes in piece-wise linear transfer function are stabilized with more diodes. By Peter Hansen and Robert Malter. Assigned too GAP/R. contributed by Ad Sprenkels in the Netherlands on 3-10-8
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Related products from other manufacturers
Z modules from Engineered Electronics Company 6 gif 1.3MB (added 12-14-5)
Full T-113 catalog for early solid state logic modules from Engineered Electronics Company - EECO 1 zipped file with 94 gif scans 18.8MB (added 3-12-7).
Brown_D-7179_chopper_amp with date code of August 3rd 1942. Traced schematic and measurements included. 1 gif, 9 jpg 0.9MB (added 12-22-28)
Former analog computer engineer Ed Lyon had some very interesting comments about the Brown chopper amp.
Kintel model 112a amplifier 6 photos of a chopper stabilized amplifier 0.4MB. Mark Stevens gave me two of these units. Thanks, Mark. (added 1-6-8)
Digitec 201 digital voltmeter This solid state DVM from the 1960's uses a chopper amplifier to achieve offset performance into the microvolt range. This offset performance level is still a challenge today. 10 jpg 1 gif 3 MOV movies 15.1MB (added 1-6-8)
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Pease Porridge, books, book excerpts and other readings.
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Current and future work past the third anniversary of the archive.
www.godaddy.com is the hosting service for the Philbrick Archive
Webmaster and archive owner Joe Sousa.
