Electronics Foundations (Art of Electronics, Ch. 1)

104 flashcards by Chris R.

What is voltage?
What is current?
Ohm's Law — state it.
Total resistance of resistors in series?
Total resistance of two resistors in parallel?
Kirchhoff's Current Law (KCL)?
Kirchhoff's Voltage Law (KVL)?
Three equivalent formulas for power dissipated in a resistor?
Shortcut for two very different resistors in parallel (e.g. 5k ‖ 10k)?
What does "conductance" G mean, and how does it relate to resistance?
What is a voltage divider, and why is it one of the most common circuit fragments?
Voltage divider output formula (R1 on top, R2 to ground)?
Why does a voltage divider's output voltage drop when you attach a load resistor?
State Thévenin's theorem in one sentence.
How do you find the Thévenin voltage V_Th of a circuit?
How do you find the Thévenin resistance R_Th of a circuit?
Rule of thumb to avoid loading down a signal source?
What load resistance maximizes power delivered to the load, for a given fixed source resistance?
How do voltage sources and current sources differ in what they "like" and "hate"?
What is small-signal (dynamic) resistance, and where does it matter (e.g. zener diodes)?
What does a capacitor fundamentally do?
Capacitor current-voltage relationship?
Energy stored in a charged capacitor?
Capacitors in parallel — total capacitance?
Capacitors in series — total capacitance?
What is the "time constant" of an RC circuit, and its units?
After one time constant, an RC discharge has fallen to what fraction of its starting voltage?
Rule of thumb: how many time constants until a capacitor is effectively fully charged/discharged?
What is a blocking (coupling) capacitor used for?
What is a bypass capacitor used for?
How does an RC differentiator work, and what's it useful for?
How does an RC integrator work?
Why doesn't a capacitor dissipate power the way a resistor does?
What does an inductor fundamentally do?
Energy stored in an inductor carrying current I?
Why is suddenly interrupting current through an inductor dangerous (an "inductive kick")?
How do you protect a switch/transistor from inductive kickback (e.g. driving a relay coil)?
What's an RC "snubber" used for?
What does a transformer do?
Why are transformers used in linear power supplies (two main functions)?
What does a diode do?
Typical forward drop: silicon diode vs. Schottky diode?
What is a half-wave rectifier?
What is a full-wave bridge rectifier, and why is it usually preferred?
What does the filter/storage capacitor after a rectifier do, and what's the sizing rule of thumb?
What is "ripple voltage," and roughly how do you estimate it?
What is a zener diode used for?
In what sense does an LED "behave like a diode" electrically?
How do you set an LED's current with a series resistor from a supply voltage V+?
What's a diode clamp/limiter circuit used for?
What's a diode "OR gate" used for (example: battery backup)?
Why put a diode across a relay coil (or any inductive load) driven by a transistor switch?
What are the stages of a simple linear DC power supply, in order?
Why use a voltage regulator IC instead of just a bigger filter capacitor?
What problem do voltage multiplier circuits (doublers, triplers) solve?
What's a "split supply," and why is it useful?
What is "reactance," and how does it differ from resistance?
Capacitor reactance formula?
Inductor reactance formula?
As frequency rises, what happens to a capacitor's impedance vs. an inductor's?
In an RC lowpass filter, where do R and C go?
RC filter breakpoint (−3dB) frequency formula (same for lowpass and highpass)?
In an RC highpass filter, where do R and C go?
What's a typical practical use for a highpass vs. a lowpass RC filter?
Rolloff rate of a simple single-section RC filter, beyond its breakpoint?
What's a "pole" (informally), and how does cascading RC sections change the rolloff?
What's the worst-case input/output impedance of a single RC filter section, and why does it matter?
Why can't you just cascade several identical RC filter sections and multiply their individual responses?
What is a parallel LC "tank" circuit, and what happens to its impedance at resonance?
Resonant frequency formula for an LC circuit?
What is a series LC "notch" or "trap" circuit used for?
What does "Q" (quality factor) describe about a resonant circuit?
Why use an LC filter instead of a simple RC filter in some applications (e.g. RF)?
Two common ways to express an AC signal's magnitude besides plain amplitude?
What is a decibel, and the formula for expressing an amplitude ratio in dB?
What is "rise time," conventionally?
What is "duty cycle"?
How do digital logic levels (HIGH/LOW) differ from a general analog signal?
What do SPST, SPDT, and DPDT describe?
What does "break before make" mean for a switch?
What's a relay, and when would you reach for one instead of a direct switch or transistor?
What's a solid-state relay (SSR), and one advantage over an electromechanical relay?
Why shouldn't you rely on a potentiometer for a precise resistance value in a circuit?
What's a trimmer pot typically used for?
Why does a reference used to bias a diode clamp (or similar circuit) need to be "stiff" (low Thévenin resistance)?
In the classic AM "crystal set" receiver, what do the three main stages do?
Why does a parallel LC circuit at resonance make a good station selector for a radio?
Circuit-lab bridge — rc_lowpass.cir smooths a Raspberry Pi PWM output into an analog voltage. Which chapter-1 concept is that, directly?
Circuit-lab bridge — voltage_divider.cir scales a 5V sensor down for a Pi's 3.3V ADC input. What must you check to avoid measurement error?
Circuit-lab bridge — led_driver.cir sets an LED's current with a series resistor. Which two chapter-1 facts does that depend on?
Circuit-lab bridge — debounce_rc.cir cleans up a noisy mechanical switch signal. Which chapter-1 idea makes that work?
Big picture: name the four passive linear building blocks from this chapter, and what "combining them usefully" mostly means.
How does impedance (Z) differ from resistance (R)? Pick the best description.
You said impedance and resistance are the same thing.
As frequency increases, what happens to a capacitor's reactance Xc = 1/(2πfC)?
You had capacitor reactance backwards.
As frequency increases, what happens to an inductor's reactance XL = 2πfL?
You mixed up inductor and capacitor reactance again.
You want to AC-couple a microphone signal into an amplifier — blocking any DC offset while passing the audio frequencies. Which RC filter topology do you need?
You picked the lowpass topology for a DC-blocking job.
Two capacitors in series — is their combined capacitance bigger or smaller than either one alone, and why?
You added capacitances in series like resistors.
What does a capacitor's capacitance C actually mean, physically?
You described capacitance like it was conductance.