Parallax Boe-Bot Student Manual page 220

Page 206 · Robotics with the Boe-Bot
Common capacitance measurements are:
•
Microfarads:
• Nanofarads:
• Picofarads:
The 103 on the 0.01 µF capacitor's case is a measurement picofarads or (pF). 103 is 10,
with three zeros added, which is 10,000. Here is how to relate 103 to 0.01 µF.
10,000 is 10 × 10
(10 × 10
which is also 0.01 × 10
which is 0.01 µF.
Figure 6-7 shows the schematic symbol for a 0.01 µF capacitor along with a drawing of
the part in your Boe-Bot parts kit. The 103 marking on the capacitor indicates its value.
Parts List:
(2) Photoresistors - CDS
(2) Capacitors – 0.01 µF (103)
(2) Resistors - 220 Ω
(red-red-brown)
(2) Jumper wires
There may also be 0.1 µF capacitors marked 104 in your kit. Do not use them in these
activities.
√ Make sure you have selected the 0.01 µF capacitors (marked 103) for this activity.
The 0.1 µF capacitors can be used in brightly lit areas, but they interfere with the Boe-Bot's
performance in indoor and low lighting activities.
Rebuilding the Photosensitive Eyes
The circuit the BASIC Stamp can use to determine light levels is called a
resistor/capacitor (RC) circuit. Figure 6-8 shows schematics of the Boe-Bot's RC light
detection circuits and Figure 6-9 shows examples wiring diagrams for the Board of
Education and the HomeWork Board.
√ Disconnect power from your board and servos.
√ Build the RC circuits shown in Figure 6-8 using Figure 6-9 as a reference.
(millionths of a Farad), abbreviated µF
(billionths of a Farad), abbreviated nF
(trillionths of a Farad), abbreviated pF
3
.
3 -12 -9
) × (1 × 10 ) F = 10 × 10 F
-6
F
0.01 µF
-6
1 µF = 1×10 F
-9
1 nF = 1×10 F
-12
1 pF = 1×10 F
Figure 6-7
Capacitor
Schematic
Symbol and
Part Drawing