122-28176 Parallax Inc, 122-28176 Datasheet - Page 185

• 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

The gain equation is:
or
A special class of a differential amp with no feedback resistor network is called a
comparator and will be explored in Chapter 6.
Digital to Analog Converter
In this section a low-pass active filter was used to develop an analog voltage from the
PWM of the digital controller. Another popular means of producing the same effect is
through the use of a Digital to Analog Converter (DAC). Just as the Analog to Digital
converter allows an analog voltage to be converted to binary and then used by the
controller, the DAC accepts a digital value from the controller and converts it to an
analog voltage.
Solid State Relays
Unlike an electromagnetic relay, which uses an electromagnetic coil to move electrically
isolated contacts to energize a large load, the Solid State Relay (SSR) has no moving
parts and may be controlled with a very small current. The BASIC Stamp controlling a
high voltage load is illustrated in Figure 5-29.
Figure 5-29 Solid State Control of Load
R
V
f
O
/R
= (V
i
I1
−V
I2
)(R
f
/R
i
) = (3 V−2 V)(100 kΩ/10 kΩ) = (1 V)(10) = 10 V