28119 Parallax Inc, 28119 Datasheet - Page 64

• Manufacturer Part Number: 28119
• Description: KIT UNDERSTANDING SIGNALS
• Manufacturer: Parallax Inc

Specifications of 28119

• Lead Free Status: Contains lead
• Accessory Type: Oscilloscope
• Interface Type: USB
• For Use With/related Products: BASIC Stamp® 2 and Board of Education
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Now how long does it take for the capacitor to charge to 3.15 V? How long does it take to
fully charge to 5 V?
By increasing the value of the resistor, the TC duration also increases. You can see that
the signal rises much more slowly. If you are using the Board of Education, the TC with a
new 1 kΩ resistor will be calculated as follows.
√
√
√
√
√
Replace the 220 Ω resistor with a 1 kΩ resistor. If you are using the HomeWork
Board, remove the jumper wire you used instead of the 220 Ω resistor, and put
the 1 kΩ resistor in its place.
Set the OPTAscope’s Horizontal dial to 20 ms.
In your program RCTimeConstant.bs2, change both instances of the
command to read
PAUSE 50
Run the modified program.
Take the same measurements with the Paired Bars cursors that you did
previously to determine the first TC of the new curve.
Figure 4-8:
Paired Bars
positioned at
the start of the
capacitor
charge (0V) and
at 3.15 V
PAUSE