UD5 Toolkit
RC & RL Filter Cutoff Frequency Calculator
Calculate the -3dB cutoff frequency for low‑pass and high‑pass RC and RL filters. Enter resistor and capacitor or inductor values.
Electronics Tools - Circuit Design
22+ toolsResistor Color Code Quiz – Test Your Electronics Knowledge
Practice reading 4‑band and 5‑band resistor color codes. Randomized challenges help you memorize the color‑digit mapping quickly.
dBm to Watts Converter - Online RF Power Unit Calculator
Convert between dBm, milliwatts, and watts. Simple calculator for RF engineers and WiFi signal analysis. Instant local calculation.
Zener Diode Regulator Calculator - Online Series Resistor & Power
Calculate the series resistor and power dissipation for a zener diode voltage regulator. Input voltage, output voltage, load current. Local only.
Ohm's Law Calculator - Online Voltage Current Resistance Power
Enter any two values (voltage, current, resistance, power) and compute the others. Visual triangle helper and formula display. Instant local calculation.
LED Series Resistor Calculator - Online Current Limiting Tool
Calculate the correct series resistor for an LED based on supply voltage, LED forward voltage, and desired current. Circuit diagram shown. Local only.
Resistors in Parallel Calculator - Online Multiple Branch Tool
Calculate the total resistance of up to 10 resistors in parallel. Enter values and see the combined resistance instantly. Local electronics helper.
LED Strip Power Calculator - Online PSU & Controller Sizing
Calculate power supply and controller requirements for any length of LED strip (5050, 2835, WS2812B). Prevents overloading. Local only.
Battery Life Calculator - Online Device Runtime Estimator
Estimate how long a battery will last given capacity (mAh/Wh) and load current. Also computes backup time for power banks. Quick and local.
Crystal Load Capacitance Calculator - Online Pierce Oscillator Tool
Calculate load capacitors for a crystal oscillator given stray capacitance and crystal CL. Essential for microcontroller circuit design. Local.
Voltage Divider Calculator - Online Two Resistor Output Tool
Calculate output voltage from a two-resistor voltage divider. Enter input voltage and resistances to see Vout. Includes circuit schematic. No data sent.
Capacitor Code Calculator - Online 3-Digit to Picofarad & Nanofarad
Convert 3-digit capacitor codes (like 104, 222) to capacitance value in pF, nF, µF. Also converts back. Useful for reading tiny ceramic capacitors.
Voltage Divider Calculator - Online Electronics Resistor Tool
Calculate the output voltage and resistor values for a voltage divider circuit. Includes schematic. Handy for electronics hobbyists and engineers.
Speaker Wire Gauge Calculator - Online Length & Impedance Guide
Find the correct wire gauge for speaker cables based on length and speaker impedance to avoid signal loss. Quick audio reference. Local.
Transistor Biasing Calculator - Online Fixed & Voltage Divider
Calculate resistor values for transistor fixed bias or voltage divider configuration. Quick quiescent point analysis.
Resistor Color Code Calculator - Online Band to Value
Select color bands to decode a resistor's value, tolerance, and temperature coefficient. Essential for anyone working with electronics hardware.
Series & Parallel Resistor Network Solver
Build a combination resistor network by adding series/parallel groups and get total resistance. Visual circuit.
Soldering Temperature Guide – Online Component & Tip Size
Select component type and solder to see recommended iron temperature and tip shape. Avoid cold joints.
Antenna Length Calculator - Online 1/4 Wave & Dipole Tool
Calculate antenna element lengths for a given frequency (or vice versa). Supports 1/4 wave, 1/2 wave, dipole. Useful for ham radio. Local only.
SMD Resistor Code Decoder - Online 3-Digit & EIA-96 Markings
Decode SMD resistor markings (3-digit, 4-digit, EIA-96) to resistance value. Enter code and get ohms instantly. Handy for PCB repair.
Battery Series/Parallel Calculator - Online Voltage & Capacity
Combine multiple identical batteries in series and parallel and see the resulting voltage and total capacity. Electronics helper.
USB Pinout Reference - Online Connector Wiring Guide
Reference diagrams for USB‑A, USB‑C, micro‑USB pinouts. See wire colors and signal descriptions. Hardware hacking helper.