Hawkins Electrical Guide

The Hawkins Electrical Guide was a technical engineering book written by Nehemiah Hawkins, first published in 1914, intended to explain the highly complex principles of the new technology of electricity in a way that could be understood by the common man. The book is notable for the extremely high number of detailed illustrations it contains, and the small softbound size of the volumes.

The book was published by Theodore Audel & Company, and the majority of the illustrative content became the basis of decades of follow-up books published under the Audels brand name. The illustrative content of these books can still be found in Audels books sold new today.

Because the Hawkins Electrical Guide was printed in the United States prior to 1923, the content of the books has passed into the public domain.

Free media access on the Internet

Due to several book digitizing initiatives such as the Gutenberg project, and The Hawkins Electrical Guide Online, many of these older public domain books are becoming available on the Internet. This series of books is currently available for free, non-commercial use from Google Books and each volume can be downloaded as a PDF, though the illustration scan quality is not as good as the ones being added to Wikipedia on this page by Wikipedia contributors.

Google Books Volume Links

As of September 2008, Google Books does not provide a simple, direct means to find each volume of this media set, and appears to include scanned copies of different volumes from different libraries and copyright dates from 1914-1917. Scan quality varies from one volume to the next. For your convenience, links to the available scanned media are provided here:

Illustrations from Volume 1

Chapter 14: The Dynamo: Current Commutation

Page 174, Figure 182
Main Wikipedia article: Gramme machine
Description: Separate excitation of an electric generator. DC generator with commutation is shown, but the principle also applies to AC alternators.
Page 175, Figure 183
Main Wikipedia article: Gramme machine
Description: A one pole, two coil Gramme ring. The second coil is wired in series with the first and the voltage of both is added together.
Page 177, Figure 185
Main Wikipedia article: Gramme machine
Description: A four coil Gramme ring. The coils of A and A' sum together as do the coils of B and B', producing two pulses of power 90 degrees out of phase with each other. When coils A and A' are at maximum output, coils B and B' are at zero output.
Page 178, Figure 186
Main Wikipedia article: Gramme machine
Description: A three pole, six coil Gramme ring, and a graph of the combined three poles, each 120 degrees out of phase from the other and summing together.

Chapter 15: Classes of Dynamo

Page 183
Main Wikipedia article: Excitation (magnetic)
Description: A self-excited shunt-wound DC generator is shown on the left, and a magneto DC generator with permanent field magnets is shown on the right. The shunt-wound generator output varies with the current draw, while the magneto output is steady regardless of load variations.
Page 196
Main Wikipedia article: Excitation (magnetic)
Description: A separately excited DC generator with bipolar field magnets. Separately excited generators like this are commonly used for large-scale power transmission plants. The smaller generator can be either a magneto with permanent field magnets or another self-excited generator.

Chapter 16: Field Magnets

Page 200, Figure 201
Main Wikipedia article: Field coil
Description: Salient pole, bipolar field, series-wound DC generator.
Page 201, Figure 203
Main Wikipedia article: Field coil
Description: Consequent pole, bipolar field, series-wound DC generator.
Page 202, Figure 206
Main Wikipedia article: Field coil
Description: Consequent pole, four-field, shunt-wound DC generator

Chapter 17: The Armature

Page 223
Main Wikipedia article: Gramme machine
Description: Early form of the Gramme ring armature with coils penetrating the interior of the ring.
Page 224
Main Wikipedia article: Gramme machine
Description: Modern design of the Gramme ring, wrapped only around the exterior of the core.
Page 225
Main Wikipedia article: Gramme machine
Description: Diagram of magnetic lines through a Gramme ring, showing the very few magnetic lines of force crossing the center gap.
Page 226
Main Wikipedia article: Gramme machine
Description: Example of a single winding around the exterior of a drum core with no wires penetrating the interior.

Chapter 19: Theory of the Armature

Page 264
Main Wikipedia article: Commutator (electric)
Description: Exaggerated example of how the field is distorted by the rotor.
Page 265
Main Wikipedia article: Commutator (electric)
Description: Iron filings show the distorted field across the rotor.
Page 281
Main Wikipedia article: Field coil
Description: Field lines of a four-pole stator passing through a Gramme ring or drum rotor.

Chapter 20: Commutation and the Commutator

Page 284
Main Wikipedia article: Commutator (electric)
Description: In a dynamo, the contact point of where a pair of brushes touch the commutator is referred to as the commutating plane. In this diagram the commutating plane is shown for just one of the brushes.
Page 285
Main Wikipedia article: Commutator (electric)
Description: Centered position of the commutating plane if there were no field distortion effects.
Page 286
Main Wikipedia article: Commutator (electric)
Description: Actual position of the commutating plane to compensate for field distortion.
Page 301, Figure 328
Main Wikipedia article: Electrical generator
Description: Dynamos are no longer used for power generation due to the size and complexity of the commutator needed for high power applications. This large belt-driven high-current dynamo produced 310 amperes at 7 volts, or 2,170 watts, when spinning at 1400 RPM.

Illustrations from Volume 2

Chapter 35: Operation of Motors

 
Page 669
Main article: Brushed DC electric motor
Description: 1917 DC motor manual starting rheostat, with no-voltage and overload release features.
 

Illustrations from Volume 4

Chapter 46: Alternating Currents

Page 669, Figure 1253
Main article: Two-phase electric power
Description: A simplified diagram of a two-phase alternator
Page 1026, Figure 1260
Main article: Three-phase electric power
Elementary six-wire three-phase alternator, with each phase using a separate pair of transmission wires.
Page 1026, Figure 1261
Main article: Three-phase electric power
Description: Elementary three-wire three-phase alternator, showing how the phases can share only three transmission wires

Illustrations from Volume 6

Chapter 68: Wave Form Measurement

Page 1850, Figure 2957
Main article: Oscilloscope
Description: Diagram of Hospitalier Ondograph
Page 1851, Figure 2958
Main article: Oscilloscope
Description: View of Hospitalier Ondograph
Page 1858, Figure 2607
Main article: Oscilloscope
Description: Duddell Moving Coil Oscilliograph
Page 1865, Figure 2620
Main article: Oscilloscope
Description: Time-index marking generator for use with Duddell moving-coil oscillograph
Page 1866, Figure 2621, 2622, 2623
Main article: Oscilloscope
Description: Interior of cinematograph camera as used on Duddell moving coil oscillograph for obtaining long records.
Page 1867, Figure 2625
Main article: Oscilloscope
Description: Oscilliograph recorded on moving film showing sparking as a high-voltage switch is opened

Illustrations from Volume 7

Chapter 66, Power Stations

Page 1979
Main article: Electric generator
Description: A 50,000 - 100,000 KVA direct-driven power station AC alternator with a separate belt-driven exciter generator.

Notes, References

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