| D latch | The D latch |
| d'Arsonval meter | What is a meter? |
| D'Arsonval meter movement | Measurements of AC magnitude |
| | AC Voltmeters and Ammeters |
| Darlington pair | The common-collector amplifier |
| data collision | Network protocols |
| dBm | Absolute dB Scales |
| DC | Voltage and current |
| | What is alternating current (AC)? |
| | Introduction |
| DC equivalent | Measurements of AC magnitude |
| DC restorer circuit | Clamper circuits |
| Debounce, switch contact | Contact "bounce" |
| Debouncing circuit | Monostable multivibrators |
| Debouncing, switch | LED sequencer |
| Deca | Metric notation |
| Deci | Metric notation |
| decibel | Decibels |
| Decimal point | Decimal versus binary numeration |
| Deckle | Bit groupings |
| decoder | Decoder |
| | Demultiplexers |
| decoupling capacitor | Low-Pass Filters |
| | Signal coupling |
| defibrillation | Physiological effects of electricity |
| degenerative feedback | Feedback |
| degree vs. radian | AC Inductor Circuits |
| Delay line memory | Historical, nonmechanical memory technologies |
| delay, propagation | Edge-triggered latches: Flip-Flops |
| Delta configuration | Three-Phase Y and Delta Configurations |
| delta-sigma ADC | Delta-Sigma ADC |
| Delta-Y conversion | Delta-Y and Y-Delta Conversions |
| Deltt | Double-Layer Tunneling Transistor |
| DeMorgan's theorem | Boolean Relationships on Venn Diagrams |
| | Minterm vs Maxterm Solution |
| | Digital logic functions |
| | Gate universality |
| demultiplexer | Demultiplexers |
| derivative | Integrator |
| Derivative of e functions | Calculus Reference |
| Derivative of a constant | Calculus Reference |
| Derivative of power and log functions | Calculus Reference |
| Derivative rules | Calculus Reference |
| Derivative, calculus | Capacitors and calculus |
| | Inductors and calculus |
| | Computational circuits |
| | Rate-of-change indicator |
| | Core saturation |
| Design Science License | Copyright |
| Detector, null | Potentiometric voltmeter |
| Determinism, network | Practical considerations |
| DIAC | The DIAC |
| Diamagnetism | Permanent magnets |
| dielectric | Electric fields and capacitance |
| Dielectric "loss" | Capacitor quirks |
| Dielectric constant | Characteristic impedance |
| Dielectric heating | Capacitor quirks |
| Dielectric strength | Insulator breakdown voltage |
| Difference, | Algebra Reference |
| Differential amplifier | Single-ended and differential amplifiers |
| | Differential Amplifier |
| | Simple Op-Amp |
| Differential pair | Operational amplifier models |
| | Differential Amplifier |
| | Simple Op-Amp |
| Differentiation | The "operational" amplifier |
| Differentiation, calculus | Computational circuits |
| | Differentiator and integrator circuits |
| | Rate-of-change indicator |
| Digit | Systems of numeration |
| Digit, decimal | Systems of numeration |
| Digit, significant | Scientific notation |
| Digital | Introduction |
| | Introduction |
| digital multimeter | Voltmeter usage |
| digital network | Networks and busses |
| Digital ramp ADC | Digital ramp ADC |
| diode | Conventional versus electron flow |
| | Other waveshapes |
| | The Shockley Diode |
| | Introduction |
| | Ohmmeter Usage |
| | Tunnel Diodes |
| | pn-Junction as Temperature Sensor |
| Diode check, meter function | Meter check of a transistor |
| | Meter check of a diode |
| diode equation | Current Mirror |
| diode equation, the | Diode Characteristic |
| diode junction capacitance | Diode ratings |
| diode leakage current | Diode ratings |
| diode PIV rating | Diode Characteristic |
| Diode tube | The triode |
| Diode, constant-current | Active mode operation |
| | JFET Current Regulator |
| | Constant-current diodes |
| Diode, steering | The NOT gate |
| | TTL NAND and AND gates |
| Diode, zener | Zener diodes |
| DIP | The "operational" amplifier |
| DIP gate packaging | DIP gate packaging |
| Dipole antenna | Principles of radio |
| direct coupling | Input and output coupling |
| Direct current | Voltage and current |
| | What is alternating current (AC)? |
| | Introduction |
| disallowed state detector | Ring Counters |
| | Johnson Counters |
| disallowed state, Johnson counter | Ring Counters |
| | Johnson Counters |
| Discharge tube | Ionization (gas-filled) tubes |
| discharging | Capacitor Charging and Discharging |
| discharging, capacitor | Electric fields and capacitance |
| Discharging, inductor | Magnetic fields and inductance |
| Disconnect switch | Safe practices |
| discontinuity | A Very Simple Circuit |
| Disk, floppy | Memory with moving parts: "Drives" |
| display tube | Display tubes |
| distortion | Mutual inductance and basic operation |
| | Practical Biasing Techniques |
| distortion, amplifier | Feedback |
| Distortion, crossover | Tubes versus Semiconductors |
| Distributive property | Boolean algebraic properties |
| Divider, current | Current divider |
| Divider, voltage | Voltage divider |
| dmux | Demultiplexers |
| Domain, frequency | Square wave signals |
| Domain, time | Square wave signals |
| don't cares in Karnaugh map | Don't Care cells in the Karnaugh map |
| doping | Doping |
| Dot convention, transformer | Phasing |
| Double insulation | Safe circuit design |
| download | Download and Release History |
| DPDT switch | Contact "normal" state and make/break sequence |
| DPST switch | Contact "normal" state and make/break sequence |
| drift | Drift |
| Drift, calibration | Rheostat range limiting |
| Drop-out current | Relay construction |
| dropout | The Shockley Diode |
| Dual Inline Package | The "operational" amplifier |
| | DIP gate packaging |
| Dual power supply | Single-ended and differential amplifiers |
| Duty cycle | AC Instrumentation Transducers |
| | Biasing techniques |
| | 555 Audio Oscillator |
| Duty cycle, square wave | The "operational" amplifier |
| Dynamic electricity | Conductors, insulators, and electron flow |
| Dynamic RAM | Modern nonmechanical memory |
| dynamometer movement | Wattmeter design |
| Dynner | Bit groupings |
