lightning Ohm's law calculator, type B
Datecirca 1935
Inventory Number1998-1-1349
ClassificationSlide Rule
Subject
Cultural Region
Place of Origin
Dimensions0.3 × 21.9 × 28.1 cm (1/8 × 8 5/8 × 11 1/16 in.)
Material
Accessoriesfour brochures for the Lightning Calculators, types A - D in library (Lib.4598a-d)
DescriptionThe Lightning Calculator for Ohms law is a cardboard rectangle. There is a dark blue border around the entire rectangle and the interior is white. There is a ruler on each of the long edges, in white lettering on the navy blue border: one side is in inches, from 1 to 10 and the other side is in centimeters from 1 to 25. There are three holes through the right long edge, for placing the calculator in a binder.
There are various scales printed on the circumference of differently-sized concentric cardboard circles or parts of circles and around the circumference of a circle directly on the cardboard backing. The concentric circles are made of white cardboard and are superimposed. There is a metal divot at the shared center that doubles as an axis of rotation for the circles. Some of the scales are written in blue and others in red. There are two transparent, off-white plastic arms that are also attached by the central divot. One of the arms is free at the other end and can rotate overtop of the rotating and fixed circular scales. The other arm extends along the vertical diameter of the circle from the center towards the top of the rectangular backing. It is fixed with another metal divot at the other end. Near the outermost circumference of the circular scales, the "Power" is written in black letters on this fixed arm with an arrow pointing downward. Toward the center of the circle "Resistance" is written in black letters on this arm with an arrow pointing upwards. The various cardboard circles and the loose arm rotate beneath this fixed arm to permit calculations.
The American Radio Relay League catalogue "Lightning Calculators" gives the following description of the scales on the calculator:
"This calculator has six scales:
A power scale from microwatts through 10 kilowatts.
A resistance scale from 0.1 ohms through 10 megaohms.
A current scale from microamperes through 100 amperes.
A voltage scale from microvolts through 100 kilovolts.
A supplementary wire scale from 0 to 40 B. & S."
The back of the lightning calculator has instructions for use printed in black lettering, color codes, and a table of equivalences.
There are various scales printed on the circumference of differently-sized concentric cardboard circles or parts of circles and around the circumference of a circle directly on the cardboard backing. The concentric circles are made of white cardboard and are superimposed. There is a metal divot at the shared center that doubles as an axis of rotation for the circles. Some of the scales are written in blue and others in red. There are two transparent, off-white plastic arms that are also attached by the central divot. One of the arms is free at the other end and can rotate overtop of the rotating and fixed circular scales. The other arm extends along the vertical diameter of the circle from the center towards the top of the rectangular backing. It is fixed with another metal divot at the other end. Near the outermost circumference of the circular scales, the "Power" is written in black letters on this fixed arm with an arrow pointing downward. Toward the center of the circle "Resistance" is written in black letters on this arm with an arrow pointing upwards. The various cardboard circles and the loose arm rotate beneath this fixed arm to permit calculations.
The American Radio Relay League catalogue "Lightning Calculators" gives the following description of the scales on the calculator:
"This calculator has six scales:
A power scale from microwatts through 10 kilowatts.
A resistance scale from 0.1 ohms through 10 megaohms.
A current scale from microamperes through 100 amperes.
A voltage scale from microvolts through 100 kilovolts.
A supplementary wire scale from 0 to 40 B. & S."
The back of the lightning calculator has instructions for use printed in black lettering, color codes, and a table of equivalences.
Signedon front of rule: PUBLISHED BY / THE AMERICAN RADIO RELAY LEAGUE, INC / Under License by W.P. Koechel
on back of rule: Published By THE AMERICAN RADIO RELAY LEAGUE, Inc., West Hartford, Conn. / Copyrighted 1935. American Radio Relay League Inc Printed in U.S.A.
FunctionThe Ohm's Law Lightning Calculator is Type B in a six-type set of slide rules for making fast calculations with Ohm's law. Ohm's law states that I = (V/R) where I is current, measured in amperes, R is the resistance of the conductor in ohms, and V is the potential difference measured across the resistance in volts. The American Radio Relay League's catalogue "Lightning Calculators" describes its function as follows:
"With [its] concentrated collection of tables, calculations may be made involving voltage, current, resistance, and can be made with a single setting of a dial. The power or voltage or current or resistance in any circuit can be found easily if any two are known. The resistance in ohms per thousand feet of copper wire is shown to the limit of the B. & S. wire gauge scale. The power ratio of any two power values expressed in decibels can readily be obtained from the calculator, and instructions are also given for finding the answers when the value is greater than 40 db, the limit of the scale. All answers will be accurate within the tolerances of commercial equipment. $1.00 POSTPAID"
"With [its] concentrated collection of tables, calculations may be made involving voltage, current, resistance, and can be made with a single setting of a dial. The power or voltage or current or resistance in any circuit can be found easily if any two are known. The resistance in ohms per thousand feet of copper wire is shown to the limit of the B. & S. wire gauge scale. The power ratio of any two power values expressed in decibels can readily be obtained from the calculator, and instructions are also given for finding the answers when the value is greater than 40 db, the limit of the scale. All answers will be accurate within the tolerances of commercial equipment. $1.00 POSTPAID"
Date: circa 1932
Accessories: four brochures for the Lightning Calculators, types A - D in library (Lib.4598a-d)
Object number: 1998-1-1374
Date: circa 1935
Accessories: four brochures for the Lightning Calculators, types A - D in library (Lib.4598a-d)
Object number: 1998-1-1375
Date: circa 1935
Accessories: four brochures for the Lightning Calculators, types A - D in library (Lib.4598a-d)
Object number: 1998-1-1377
Date: circa 1935
Accessories: four brochures for the Lightning Calculators, types A - D in library (Lib. 4598a - d)
Object number: 1998-1-1376
Panelvision Corporation
Date: 1984
Accessories: single-board display controller
cable for display (1997-1-0686c)
shipping ticket/ hand carry pass dated June 11, 1997 (in instrument file)
letter to Dr. Richard V. Kollarits from William Andrewes dated June 16, 1997 regarding donation of MiniGraphic display and letter to William Andrewes from Dr. Richard V. Kollarits that accompanied the object upon donation on June 11, 1997 (in instrument file)
four sample color prints made with this display on micro-encapsulated photographic paper. 1. man in business suit, 2. woman crouching next to lawn ornament, 3. two clowns painting a third's face, 4. woman in winter hat and scarf (in instrument file)
copies of two articles by AT&T Bell Laboratories staff (Richard V. Kollarits, William, H. Ninke, David C. Gibbon) on color imaging and printing (in instrument file)
Panelvision pamphlet introducing the MiniGraphic multipurpose flat panel display, including instrument specifications, consumer prices, functioning and features (in instrument file)
1984 article by Panelvision employees (Peter Brody Fang-Chen Luo, Paul Malmberg) on active matrix technology (in instrument file)
Panelvision Corporation Fact Sheet, including details of company history and recent developments (in instrument file)
article about commercial debut of active matrix technology from Design Engineering newspaper, June 18, 1984 (in instrument file)
full circuit diagram and schematic for MiniGraphic Display Controller (in instrument file)
instruction manual and description of MiniGraphic Display Controller (two copies, in instrument file)
circuit diagrams and instruction manuals for the MiniGraphic Display (two booklets, in instrument file)
Object number: 1997-1-0686a
Frank S. Baldwin
Date: 1897-1907
Accessories: instruction manual (in object file); history of instrument (both in very poor condition)
Object number: 1997-1-0246
Jakob Amsler
Date: circa 1906
Accessories: instrument is in four (4) parts; the rail is in own box and is inventory # 2006-1-0002b; letter from Prof. William Brower containing the complete history of ownership and use (missing)
Object number: 2006-1-0002a
Kingson
Date: 1960s-early 1970s
Accessories: leather slide case; single sheet of paper with instructions for use folded and inside the leather case
Object number: 1997-1-1927
