Supported Features
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Larger Text
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Dark Interface
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Differentiate Without Colour Alone
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Sufficient Contrast
BenchKit: Electronics Tools
Resistor, trace, drop, divider
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Read a 3- to 6-band resistor or an SMD code, size a PCB trace, check a cable drop, pick an E24/E96 divider. Type 4k7 or 3V3 as written. Every result shows its limits.
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.
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
• The answer now sits on top, with its limits right beside the number: IPC-2221 chart range, constant-current drop, ideal unloaded divider.
• Tap a band on a drawn resistor and pick its color; it moves to the next band by itself. 3-band resistors and SMD codes are new.
• Type values the way you write them: 4k7, 2R2, 100m, 3V3. Each tool remembers your last inputs.
• Voltage Divider finds the closest E24/E96 resistor pairs for a target and shows what a load does to the output.
• Voltage Drop works from wire gauge and length; PCB Trace also solves current from width.
• A cleaner icon with dark and tinted versions, and formulas and sources for every tool.
The developer, 明 齐, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
The developer indicated that this app supports the following accessibility features. Learn More
Information
- Provider
- 明 齐
- Size
- 3.4 MB
- Category
- Utilities
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.0 or later.
- iPhone
- Languages
English and 2 more
- English, Japanese, Simplified Chinese
- Age Rating
4+
- 4+
- Copyright
- © Ming Qi