122-28176 Parallax Inc, 122-28176 Datasheet - Page 205

• 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

From this equation we can see that a gain of 10 is required and 7 must be subtracted from
the product. There are op-amp configurations that can add or subtract voltages, called
summing amplifiers.
equation of V
This circuit utilizes a two-stage op-amp configuration to perform the equation or transfer
function. Stage 1 provides the gain using an inverting amplifier. The Stage 2 amplifier is
configured as a summing amplifier.
Stage 1:
Stage 2:
Combining the results of the two stages provides the final voltage into the ADC.
5 V = 10(1.2 V) + b
5 V−12 V = b
b = −7 V
y = 10(x) −7 V or VADC = 10(VIN) − 7 V
V
V
V
V
V
V
S1
S1
O
O
O
O
= − (− 10 V
= V
= −V
= −V
= 10 V
= V
= V
= (−R
= − 10 V
= (−100 kΩ/10 kΩ)V
O
= 10(V
S1
S1
S1
S1
S1
(−R
(−10 kΩ/10 kΩ) + 0.7 (−10 kΩ/1 kΩ)
(−1) +0.7 (−10)
f1
−7
−7
I
/R
− 7
f2
i1
I
I
/R
) −7 V.
)V
I
Figure 6-10 illustrates an op-amp circuit which performs the
) − 7
i2
I
) + V
offset
I
(−R
f2
/R
i3
)