Amp Nerd https://validator.w3.org/feed/docs/rss2.html Blog A Capacitor Can Hold Charge After Power Is Removed Resistor Wattage Is a Heat Limit, Not the Power It Always Uses Why LEDs Need Current Control Even on a Small Battery A Diode Is Not a Perfect One-Way Valve MOSFET Gate Voltage Can Look Right While the Device Gets Hot Relay Contacts and Relay Coils Have Different Ratings Why Inductive Loads Create a Voltage Spike When Switched Off A Thermistor Changes Resistance with Temperature—But Which Way? Why a Crystal Oscillator Is Accurate but Not Perfect Decoupling Capacitors Help Locally—Placement Changes the Result Home True RMS Matters Most When the Waveform Is Not a Sine Wave Continuity Beeps Do Not Prove a Connection Can Carry Load A Clamp Meter Needs the Right Conductor Inside Its Jaws Auto-Ranging Can Hide a Unit Change in Plain Sight Meter Counts and Digits: What the Display Specification Really Means Non-Contact Voltage Testers Can Miss or Misread a Situation Why Measuring Current Uses a Different Connection Than Voltage Thermal Cameras Can Misread Shiny Metal—Emissivity Is the Catch A Plug-In Power Meter Needs More Than a Big Display Scope Probe Ground Clips Can Create a Short—They Are Not Floating by Default A 12V Adapter Fits the Socket—That Does Not Make It Compatible Can You Use a Higher-Amp Power Adapter? The Load Still Matters Why a Power Supply Clicks On and Off Under Load A Power Supply Measures 12V with Nothing Connected—So Why Does It Fail? Ripple Is Not the Same as the Average DC Voltage Linear vs Switching Power Supplies: The Tradeoff Is Bigger Than Noise Why a Power Supply Needs Minimum Ventilation Even at Half Load Isolation Is an Electrical Barrier, Not a Marketing Synonym for Safe Why a Charger Can Whine at Night When the House Is Quiet Hold-Up Time: The Tiny Energy Reserve That Can Prevent a Reset Motor Startup Current Can Dwarf Running Current—Without a Fault Why a Stalled Motor Can Overheat So Quickly A Fan Speed Controller Is Not Always a Light Dimmer Brushless Motors Still Need Switching—The Brushes Moved into Electronics Why a Small Fan Can Be Loud Even When It Uses Little Power Motor Nameplate RPM Is Not Always the Speed You Measure Why Motor Bearings Can Waste Energy Before They Seize A Capacitor-Start Motor Is Not Storing a Burst of Battery-Like Energy Variable-Speed Drives Save Energy in Some Loads, Not Every Load Why a Motor Can Be Hot Without Being Overloaded A 100W Amplifier Is Not Twice as Loud as a 50W Amplifier Speaker Impedance Says 8 Ohms—Why Does It Change with Frequency? Clipping Can Sound Loud Before It Sounds Good Class D Amplifiers Are Not Automatically Digital A Ground Loop Makes Your Speakers Hum—Do Not Remove the Safety Ground Balanced Audio Cables Reject Noise—But Only with the Right Connections A Subwoofer Needs More Than a Big Watt Number Why Headphone Volume Changes Between Devices