1. Op-Amps and Analog Computers
Analog computers – a number is represented as a single voltage
Differentiator
Summing amplifier
Integrator

2. Digital Computers
Digital computers – numbers are represented by several voltages in “binary code”
128 64 32 16 8 4 2 1
bit
voltage 0V 3V
51 in 8-bit binary code is
Double precision floating-point variable – 64 bits or 8 bytes
Single precision floating-point variable – 32 bits or 4 bytes

3. Parallel vs. Serial Parallel – N wires carry N bits simultaneously
Serial – Single wire, binary data sent as “packets 1
8 bits sent in parallel

4. Digital Data Aquisition
A/D – analog to digital converter
Continuous Analog
Discrete Digital
Discrete Digital
D/A – digital to analog converter (i.e. an iPod)
“Continuous” Analog

5. Sampling Frequency and Nyquist Criterion
Quality of a digital signal depends on the Sampling Frequency fS
Discrete Digital
“Continuous” Analog
Nyquist Criterion – The maximum frequency component that can be resolved is half the sampling frequency

6. Ultrasonic Frequencies
Our ear has poor response to frequencies > 20kHz.

7. Transient Response

8. HAVE A TENDENCY TO OSCILLATE!
Capacitive and Piezoelectric Sensors h
HAVE A TENDENCY TO OSCILLATE! h
Spring mass system
Hook’s law
Accelerometer
Pressure