Errata Page
Robot Builder's Bonanza, Second Edition

Errata, comments, and reader suggestions.

Last updated January 15, 2004


Page 75:

Heading: Cleaning supplies; I think you mean 'contact cleaner' not 'contract cleaner.'

Heading: solder vacuum; you say "most stores sell a spool of solder vacuum specifically for removing solder." when I believe you mean 'spool of solder braid'.

Contributed by David M./ElectroTX via e-mail.

Page 148:

LEGO plates are one-third the height of LEGO bricks, not one half, as stated in the text.

Contributed by Tyler and David M./ElectroTX via e-mail.

David M./ElectroTX writes via e-mail:

Beginning with chapter 12, you refer to the connecting mechanism on Lego
pieces as "bumps" or "nubs", when in Lego terminology they are called

On Page 148:
You write "Plates are like bricks but half their height. ..." Lego
plates are actually _one-third_ the height of bricks or beams.

On page 149:

You write "Stud axle. Stud (or "cross") axles come in various lengths,
..." To avoid confusion, they should be called by the Lego standard
"axle" or "cross axle." When you use the term 'stud axle' it is usually
in conjunction with a number, denoting its length, (e.g. 'an 8-stud
axle'), meaning it is as long as an 8 stud beam; 'stud' being the term
for the bumps on a brick.
You also say, "They have a spine of four studs along their length."
Again, to avoid confusion, you might say, 'The axles have four splines
at 90 degrees which mate with the cross-axle holes in gears, pulleys,
bushings, etc.'

Page 238:

Under Operating Voltage, should read: "at more than 30 or 40 percent over its rated voltage"

Contributed by John Piccirillo via e-mail.


Page 241:

Figure 17.5. The figure is misleading. The torque is measured as the force perpendicular to the lever arm.

Contributed by John Piccirillo via e-mail.


Page 243:

"Decreasing the speed of the motor also increases its torque" is confusing. The statement refers to the speed of the motor output after gear reduction.

Contributed by John Piccirillo via e-mail.


Page 260, 263, 266:

Several readers have objected to the H-bridge design on these pages as they use only NPN transistors, instead of NPN/PNP pairs (the circuit on pages 263 and 266 uses N-channel MOSFET devices instead of N- and P-channel pairs). As it states in the text, these designs are suitable for reference, and (as stated on page 262), even better bridges use complimentary transistors. These circuits will work as presented, but note that better designs use complimentary transistor pairs, "voltage pumps," and other techniques to maximize efficiency and power.


Page 287:

The correct part number for the flip-flop IC is 7476 (the top half of the chip is labeled 7576).

Contributed by Jim T on c.r.m.

Also, pins 13 and 5 of the 7476 are reversed. Pin 13 is Gnd; pin 5 is Vcc.

Page 288:

IC2 is mislabelled as 4037 in the parts list table, when it should be 4027.

Contributed by Rich Fox via e-mail.

 Page 289:

The correct part number for the <1 amp transistors in Parts List 19.4 is TIP31 (the TIP32 part is a PNP transistor).

Contributed by tmbg on c.r.m.

Page 298:

Figure 20.3 Some arrows have been misplaced. The top arrow marked "Length of pulse changes to control position of servo" indicates not the length of the pulse but the refresh duration. The arrow on the bottom is marked "same period for all signals" but the doesn't extend to the end of the period.

Contributed by John Piccirillo via e-mail.


Page 366:

Under Using SMA, "Because SMAs expand as they contract..." is confusing. The material will pull from its terminating points, hence the need for secure termination.

Contributed by John Piccirillo via e-mail.

Page 375:

Write Keith McGerald via e-mail:

On page 375, in the second to last paragraph you wrote "pressurize the
air or oil, and values are used to control" but I think you meant
valves not values.

Page 458:

The XOR truth table incorrectly shows an output value of "1" when both input values are "1." The correct value is "0."

Contributed by Dave Sousa via e-mail.

Page 460:

Writes Glenn Anaiscourt via e-mail:

"The Fundamental Approach", paragraph 1, one of the sentences is missing a 'them': "Whether
these features are built into the motherboard or added by plugging in a daughter board, *all of are*
input/output (I/O) ports of one type or another."

Page 466:

 Pin 15 from the parallel port is duplicated. The CR/LF functionality (to IC2) should connect to Pin 14 of the parallel port.

Contributed by Chris Hughes via e-mial.

Page 468:

Use 330 ohm resistors for the Robot Experimenter's Interface test jig.

Page 477:

Figure 30.10 missing specific pin number for top ENABLE line. Any available output pin can be used, but for the sake of example, pin 16 is one possibility.

Contributed by Bill Mania via e-mail.

Page 496:

Figure 31.8 caption talks about capacitors, but none are shown in the figure. However, they are discussed in the text at the top of the page.

Contributed by Glenn Anaiscourt via e-mail.

Page 545:

Resistor R2 has a value of 56 ohms (the "W" is a typographical error due to converting a Windows-based schematic to the Macintosh platform).


Page 550:

Bottom of the page says, "I have specified the use of two high-output infrared LEDs". Here, the word specified means this is the design recommendation.

Contributed by John Piccirillo via e-mail.


Page 562:

The vertical legend in the graph should read: 0, 50, 100, 150, 200, 250, 300.

Contributed by Jason Cozad on c.r.m.


Page 566:

Last paragraph, should refer to pin 13 of 4066, not pin 3. Also, the LED is not shown in Figure 35.10, but instead a generic output for connection to other circuitry.

Contributed by John Piccirillo via e-mail.


Page 581:

The circuit in Figure 36.11 is designed to be used at +5vdc. Using a higher voltage may require altering component values. For ease of use, replace R3/R4 and R6/R7 with 20K potentiometers (connect the wiper of the pot to the appropriate input of the op-amp; connect the other two leads of each pot to +5vdc and ground). Experiment with the value of R8, or omit.

Contributed by Chris Renton and Gerald Coe on c.r.m.


Page 595:

Writes John Piccirillo via e-mail:

Most any alcohol usable for cleaning will suffice. Isopropyl alcohol should not be used if it contains more than 20 percent water ("technical" grade), or another cleaner as an active ingredient.

Page 605:

Writes Glenn Anaiscourt via e-mail:

Paragraph 4, you write, "Note the short pulse that appears at pin 13, the End-of-Conversion (EOC) Output." On the accompanying schematic, the pin is labeled as number 7.


Page 606:

The pinout diagram shown in the circuit is for an ADC0808 analog-to-digital converter (an ADC with eight analog inputs). The ADC0816 is configured similarly, but uses a different pinout diagram, as it supports 16 analog inputs. The pinout diagram for the ADC0816 is available at

Contributed by Jim T on c.r.m.


Page 610:

The correct part number for the static RAM chip is 2112 (the figure caption says 2114).

Contributed by Jim T on c.r.m.


Page 634:

Writes John Piccirillo via e-mail:

Page 638:

Writes John Piccirillo via e-mail:

Page 665:

"…you can get audio amplifiers with wattages of 8, 16 and even more volts…" Volts should be watts.

Contributed by Glenn Anaiscourt via e-mail.

Page 668:

Table 40.4 should read: Parts List for Gain-of-50 Audio Amplifier"

Contributed by John Piccirillo via e-mail.


Page 676:

Writes John Piccirillo via e-mail:

See Appendix E for a recommended generalized circuit.

Resistor R1 in the schematic of Figure 40.11 should be 5K precision trimmer (the parts list in Table 40.7 erroneously lists a 50K trimmer; it is supposed to be listed as a 5.0K precision 3-to 15-turn trimmer potentiometer). For the center frequency designated for the circuit, the trimmer will be at about its center position at 1 kHz.

Page 722:

Writes via e-mail:

"Under the heading Electronics/Mechanical Mail Order:New, Used, and Surplus the website for All Electronics is written as but it should be


Page 742:

Signal out values (HI, LOW) are reversed for the middle and bottom figures. The mislabeled resistor in the middle figure is 4.7K.

Contributed by Brian on c.r.m.



From Shae Reichhart via e-mail:


Under Bumper switches: correct page reference is page 581, not 561.

Contributed by Tristan Heft via e-mail.

From David M.via e-mail:


Send In Your Fixes!

I want to thank those who have provided feedback via e-mail and on the comp.robotics.misc (c.r.m.) newsgroup!

Please forward your bug fixes and comments to gort at