122-28176 Parallax Inc, 122-28176 Datasheet - Page 78

• Manufacturer Part Number: 122-28176
• Description: GUIDE STUDENT PROCESS CONTROL
• Manufacturer: Parallax Inc

Specifications of 122-28176

• Accessory Type: Manual
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant

Has the load line for the 1 kΩ resistor changed?
potentiometer is required over the full active region as compared to the 47 kΩ? When R
is reduced, the base current is higher for the same voltages. Because I
higher over a smaller movement range of the potentiometer.
Challenge 3-5: Considerations for a Transistor Switch
Other Considerations in Sizing Resistors
While it may appear that a high value of R
transistor, this is not necessarily the case. The switching speed of the circuit is faster as
the value of R
later chapters we will see this in action. Figure 3-15 is a characteristic curve of rise time
(t
As I
approximately the time required to go from cutoff to saturation. The lower the rise time
value, the faster the transistor can go from cutoff to saturation and vice-versa. Increasing
R
r
C
) vs. I
leads to increased sensitivity but slower switching.
√
√
√
√
1. If the transistor were being used as a digital switch, would a higher or lower
2. What would the DC Load Line look like if a 100 kΩ resistor were used for R
C
C
increases (lower R
Reset the plot and re-acquaint yourself with the results of movement for the
potentiometer.
Replace R
Reset the plot and adjust the potentiometer very slowly to obtain a new plot.
Return R
value of R
Why?
Draw a plot of the Load Line and Power.
readability.
.
C
decreases. The data sheets for the 2N3904 can lend credence to this. In
B
B
C
to a value of 47 kΩ.
with the 10 kΩ resistor.
be desirable based on the DC Load Line and input voltage response?
C
), the rise time of the transistor decreases.
C
is desirable for switching action of a
Scale the plot accordingly for
How much movement of the
B
is higher, I
This is
C
C
is
B
?