basic electronic components. crystals equivalent circuit to crystal
TRANSCRIPT
Basic Electronic Components
Crystals
Equivalent Circuit to Crystal
Crystal– Schematic Symbol
Piezoelectric Crystals
“Squeezing” the crystal produces an EMF
Squeeze the x-axis and a voltage difference occurs on the y-axis
Place a voltage difference on the y-axis and the x-axis contracts or expands
Switches
Relays
Relay Consists of two parts: coil and switch
Current flowing through the coil will create magnetic field A strong enough magnetic field will pull the switch When current stops, switch moves back into original position
SPST– Single Post, Single Throw SPDT– Single Post, Double Throw– three switch positions
Light Bulb
Tube Diode
Tube diodes have three elements Filament—Heats up
cathode so it can donate electrons easily
Anode (positively charged plate)– emitter of electrons
Cathode (negatively charged plate)—collector of electrons
Current only flows in one direction from anode to cathode When “reverse biased”,
no current flow
Effect of Diode on AC voltage source
Diode plus capacitor
Triode—Addition of another element called the “grid”
Grid is a metallic mesh (holes to let electrons flow through). How many electrons flow through grid depends on charge
Negatively charged grid repels electrons Positively charged grid attracts electrons
The ratio of the voltage into a triode to the voltage supplied by the triode is called the “gain” (gain=voltage out/ voltage in)
Old School– Cathode Ray Tube (CRT)
Structure of germanium (similar to silicon)
Ge doped with Arsenic (As)
Note the extra electron
Voltage applied to Ge(As)
Ge doped with Indium
Note missing electron
Voltage applied to Ge(In)
A PN junction
Ge(In) + Ge(As)Note more positive charge carriers on
left than right
Applying a positive voltage to the N side (called reverse biased)
A forward biased PN junction
Note that the behavior of a PN junction is exactly like that of a diode
Current can only flow one way
Schematic Diagram of Diode
Other diodes:Light Emitting Diodes (LED)
Give off light as current passes through themDark when forward biased
How Transistors Work
Op-Amps– Equivalent Circuit
Transistor Symbol
Chip Layouts for Op Amps
Schematic and Necessary Inputs to Op Amps
Inverting Amplifiers Output voltage is negative of
input voltage Gain (G) is equal to
G=-R2/R1
Inverting, unity amplifier when R2=R1
If we replace R2 with a capacitor– circuit becomes an integrator
Since G is now a function of w, then lower frequencies are amplified with a greater than 1 gain
Called a “low pass filter” If we replace R1 with a capacitor-
then lower frequencies are attenuated
Called a “high pass filter” Sometimes called a
“differentiator”
Non-inverting Amplifiers
G= 1+ (R2/R1)