Bad Circuits

Learning from mistakes — on this page we link to plenty of amusing (and educational) circuit blunders.

Passive Circuits

(Chapter 1)

• voltage divider
• full-wave bridge rectifier
• electrician’s 3-way light switch

Transistor Circuits

(Chapter 2)

• ac-coupled emitter follower
• BJT current sink
• high-current BJT switch
• push-pull BJT follower

FETs

(Chapter 3)

• CMOS inverter
• high-side power switch
• JFET switch

Op-amps

(Chapter 4)

• ac-coupled x10 amplifier
• x100 audio amplifier
• JFET hybrid current source
• op-amp clamp circuit
• op-amp current source – 1
• op-amp current source – 2
• positive 15V regulator – 1
• positive-rail booster
• selectable-gain dc amplifier
• triangle-wave generator

Filters

(Chapter 6)

• VCVS bandpass filter

Oscillators and Timers

(Chapter 7)

• voltage-controlled 555 oscillator
• delayed-pulse generator

Low-noise Techniques

(Chapter 8)

• lownoise NF matching

Voltage Regulation and Power Conversion

(Chapter 9)

• simplest 5V regulator
• 3.3V regulator using a 317
• split ±12V supply
• discrete linear regulator

Digital Logic

(Chapter 10)

• wired-OR
• logic-level indicators
• logic to high-power load
• alternate-pulse remover