70009 Parallax Inc, 70009 Datasheet - Page 60

• Manufacturer Part Number: 70009
• Description: BOOK UNDERSTANDING SIGNALS
• Manufacturer: Parallax Inc
• Type: Signal Analysisr

Specifications of 70009

• Style: Book
• Title: Understanding Signals
• Contents: Guide to Generate, View and Measure Wave Forms
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Other names: 70009PAR

ACTIVTY #1: VERIFYING THE CALCULATED RESISTOR/CAPACITOR
NETWORK TIME CONSTANT
In this activity we will measure the resistor/capacitor time constant and verify the value
with an OPTAscope measurement.
Required
(1) 220 Ω resistor
(1) 10 µF capacitor
(5) Jumper wires
Building the RCTime Constant Circuit
√
√
P15
P0
Build the circuit as shown in Figure 4-4 and Figure 4-5 , paying attention to the
polarity of the capacitor. If you are using a BASIC Stamp HomeWork Board
leave the 220 Ω resistor out. Use a jumper wire to make the necessary
connection.
Attach the CH1, CH2 and Ground probes as shown in Figure 4-4.
WARNING: The 10 µF capacitor can explode if it is connected improperly!
Always disconnect the power before building or modifying circuits. Carefully check the
polarity of the 10 µF capacitor. The positive terminal (longer leg) must be connected to a
power source pin and the negative terminal (shorter leg) must be connected to Vss (ground).
220
Ω
Vss
10 µF
OPTA
OPTA
OPTA
scope
scope
scope
CH2
CH1
GND
Figure 4-4:
Resistor / capacitor
circuit for RC time
constant
measurement
Note: If you are using
the BASIC Stamp
HomeWork Board,
do not put the 220 Ω
resistor in the circuit
(this resistor is
already surface
mounted onto the
PCB).