BenchKit vs OhmNote

BenchKit puts four everyday electronics calculations in one focused, offline iPhone app. RESISTOR CODES Decode 3, 4, 5, and 6-band axial resistors by tapping the bands on a drawn resistor, or SMD codes (3-digit, 4-digit, EIA-96, R notation). See the tolerance range, IEC marking code, and standard E-series match, with a warning when a reading is probably reversed. PCB TRACE WIDTH Estimate minimum internal or external copper trace width from current, copper weight, and allowed temperature rise, in millimeters and mils, or the current a given width can carry. Results outside the IPC-2221 chart range are flagged as extrapolations. VOLTAGE DROP Voltage drop, voltage at the load, power lost in the wiring, and the share of supply that reaches the load. Enter the round-trip resistance, or wire gauge (AWG or mm²), length, and conductor temperature. VOLTAGE DIVIDER Ideal unloaded output voltage, divider current, per-resistor dissipation, output resistance, and what an optional load does to the output. Or enter a target voltage and get the closest E24/E96 resistor pairs with their worst-case output. Type values the way engineers write them: 4k7, 2R2, 100m, 3V3; the keyboard has keys for the letters. No account. No ads. No analytics. No network connection. English, Simplified Chinese, and Japanese. BenchKit is a quick estimation tool. Always verify production designs against component datasheets, applicable standards, simulation, and physical validation.

OhmNote is the electronics calculator that finally takes vacuum tubes seriously. Whether you're designing a valve amplifier, winding a transformer, restoring vintage gear, or just learning Ohm's law, OhmNote puts many precise, beautifully crafted tools in your pocket - and it all works completely offline, with no ads and no account. From a quick resistor color-code lookup to plotting a load line and winding your own output transformer, it's the rare toolkit that covers everyday electronics AND the deep tube-amp math most apps ignore. BUILT FOR VACUUM-TUBE ENTHUSIASTS Tube Analyzer - plot the load line, set the Q-point, and read gain, set bias, estimate distortion and more in real time Tube database - specs, operating points and applications for hundreds of tubes Tube pinouts - clear base diagrams at a glance for thousands of tubes Tube substitution - find compatible replacements and equivalents Tester settings - ready-to-use setups for popular tube testers TRANSFORMERS & MAGNETICS Output transformer (OPT) designer - turns ratio, primary inductance, air gap and saturation check Power transformer designer - VA, turns-per-volt, every winding and its wire gauge Gapped-core choke designer for power-supply filtering Air-core inductor (Wheeler) - turns ↔ inductance, both directions Transformer ratio & impedance, plus wire gauge (AWG ↔ SWG ↔ mm) Inductive Reactance of coil or transformer - inductance ↔ impedance ↔ frequency EVERYDAY ELECTRONICS Ohm's law & power - solve for any value Resistor color code (4/5/6-band + SMD) - read or generate Capacitor code decoder, LED resistor, voltage divider Series/parallel resistors, capacitors and inductors Reactance, RC/RL time constants, resonant frequency dB converter, frequency ↔ period POWER & SIGNAL Adjustable regulator (LM317 family) with heat & heatsink check Zener regulator designer Stepped attenuator (log volume control) designer RC/RL passive filters with drawn schematics Resistor & capacitor combination finder Connector pinouts - USB, HDMI, VGA, RS-232 and more WHY YOU'LL LOVE IT Solve forward OR reverse - enter what you know, get what you need Smart SI-unit input - just type 4.7k, 100n, 1M… Instant results as you type Fully offline - no internet required No account, no ads, privacy-first Gorgeous light & dark themes Available in English, Vietnamese, Spanish, French and German OhmNote is made for guitar and hi-fi amp builders, audiophiles, ham radio operators, repair techs, students and working engineers - anyone who wants fast, trustworthy answers without the clutter. Download OhmNote and build with confidence. Terms of Use (EULA): https://ohmnote.com/terms Privacy Policy: https://ohmnote.com/privacy