Low Frequency Detector vs Voltage Divider Calc

"Low Frequency Detector" is an acoustic measurement tool for detecting low-frequency sounds that is hard to hear in normal situation. The human ear is not sensitive enough to low-frequency sounds. If you are exposed to noise from nearby construction or factories without realizing it, you may feel discomfort or a sense of pressure. In such cases, you can use this app to check what kind of low-frequency noise is present. Generally, low-frequency sounds is a sound wave ranging from 1Hz to 100Hz. Depending on its frequency component and sound level, the degree of influence on the human body and the noise sensation is different. This app allows you to examine the frequency component of low-frequency sounds by 1/3 octave band analysis and FFT analysis. Features: - Low-frequency power level measurement less than 100Hz (LF Level): Flat characteristic, Updating indication of measurement period 1 sec. - Power level measurement in the audible band (Leq): Flat characteristic, Updating indication of measurement period 200ms. - 1/3 octave band analysis (OCT) - FFT analysis (FFT) - Time course graph (TIME) - Snapshot (Snap) on the measurement display screen. - Report function (Report): Analysis report of a peak LF Level with TIME, OCT and FFT. - Measurement time: up to 60 sec Functions: The measurement analysis is performed in the following step. Be sure to set the measurement conditions in Step-1 once before starting the sound measurement. 1) Calibration (Calibrate): The reference signal (1kHz sine wave) is output to determine the reference noise level for the low-frequency component. If the volume level of iPhone is set to about 20-50%, the calibration will automatically adjust it to the optimum volume level for the reference signal. 2) Measurement (Measure): Analyze a power level of low-frequency sounds. - LF Level (dB): Low-frequency power level less than 100Hz. - Leq (dB): Sound power level with the frequency weight characteristic Z (Flat) of the audible band. 3) Measurement display: It can select either 1/3 octave band frequency analysis, FFT analysis or Time course graph. They are updated in real time. 4) Report: Measurement result report. It is effective when measuring for 10 seconds or more. # Time course graph: TIME - Low-frequency (LF) Level (dB): Time course graph with peak level noise level judgment (RED-very noisy, YELLOW-noisy, GREEN-normal) at the peak level. - LF max (dB): maximum dB value of low frequency. # Frequency response graph: OCT, FFT - OCT Band LF max (dB): maximum dB value in 1/3 octave band at LF max observation. - Max Level Frequency (Hz): peak frequency at LF max observation. Notes: - The sound measurement of the low-frequency range is a level difference with respect to the reference signal, which indicates the relative power level. - The reference signal is output during calibration and sound level measurement. - Do not change the volume level of iPhone after the calibration. - White line in the OCT and FFT modes indicates frequency characteristics in frequency weight correction of G characteristics. - Since iPhone's built-in microphone has a lower sensitivity on the very low frequency range, it is not recommended to measure a huge volume sound near a very loud noise source. - Since it takes a while for the observation value to stabilize immediately after the start of measurement, the maximum value is calculated from about 2 seconds later. - In the case high power of 1kHz component is included in the measured noise source, the precision of measured value by this app largely decreases. - Sudden noise or impulsive sounds are not low frequency noises in general. - The previous calibration information can be maintained internally. - The analysis results may vary due to individual differences in iPhone devices. - The authorization to access built-in microphone and Photos will be confirmed by iOS system at first access. Please visit our iOS app support page for more information.

Voltage Divider Calculator is a practical electronics tool for quickly calculating resistor divider circuits, output voltage, input voltage, and resistor values. Built for students, makers, technicians, and electrical engineers, it helps you solve common voltage divider problems with a clear interface and fast, reliable results. Whether you are designing an Arduino input circuit, scaling a sensor signal, choosing resistor values for a reference voltage, learning basic electronics, or checking a circuit before building it, this app gives you the numbers you need without extra complexity. Calculate voltage divider results from known resistor and voltage values, explore different calculation modes, and work with common resistor units such as ohms, kilo-ohms, and mega-ohms. The app is designed to make everyday electronics calculations easier, especially when switching between units or comparing circuit options. Key features include: • Calculate voltage divider output voltage • Solve for input voltage, R1, or R2 depending on your circuit need • Support for common resistor units • Clean input fields for fast calculation • Presets for commonly used resistor values • Calculation history for reviewing previous results • Circuit diagram view for easier understanding • Educational reference content for learning how voltage dividers work • Locale-aware number input for international users • Simple, focused design for electronics work Voltage dividers are widely used in analog circuits, embedded systems, microcontroller projects, battery monitoring, sensor interfacing, signal scaling, reference voltage generation, and many other electronics applications. This calculator helps reduce manual math and makes it easier to test resistor combinations before committing to a circuit. For students, the app provides a convenient way to understand the relationship between input voltage, output voltage, R1, and R2. For engineers and hobbyists, it works as a fast pocket reference when designing or debugging circuits. Use Voltage Divider Calculator when you need to: • Step down a voltage for a microcontroller input • Estimate sensor output scaling • Choose resistor values for a target voltage • Verify circuit calculations • Compare divider ratios • Learn and apply the voltage divider formula • Save and revisit previous calculations The app focuses on clarity, speed, and accuracy, making it suitable for classroom learning, lab work, electronics repair, prototyping, and PCB design preparation. It keeps the workflow simple: enter your values, choose the calculation mode, review the result, and continue designing. Voltage Divider Calculator is a useful companion for anyone working with electronics, circuit design, electrical engineering, Arduino projects, Raspberry Pi hardware, embedded systems, analog circuits, or resistor networks. Thanks for your support and do visit nitrio.com for more apps for your iOS devices.