Tools

555 astable schematic with R1, R2 and C, above the square-wave output and the capacitor charging between one third and two thirds of Vcc

555 Timer Calculator: Astable, Monostable, PWM, VCO and Ramp Design 555 timer circuits for astable, monostable, PWM, VCO, ramp and latch operation, with practical component limits. Open the tool →

chematic of a three-terminal 78xx regulator with input and output capacitors and a ground symbol, next to the three design checks: dropout, power dissipation and junction temperature.

78xx/79xx Linear Regulator Calculator: Ripple, Dropout, Heat and Noise Calculate 78xx and 79xx linear regulator supplies: rectifier ripple, dropout margin, heatsink sizing, residual noise and protection. Open the tool →

Burette above a flask changing color beside a titration curve and indicator transition band

Acid-Base Titration Indicator Selector: Color Change & Endpoint Error Choose a titration indicator and compare the curve, color transition and endpoint error. Open the tool →

BJT stage biased by an R1-R2 voltage divider, with collector resistor Rc and emitter resistor Re, next to a load line crossing the transistor characteristic at the operating point Q.

BJT Calculator: Biasing, Amplification, and Switching BJT calculator for biasing, Q-point, small-signal gain, load lines, coupling capacitors, cascaded stages, and switching. Open the tool →

Technical cover showing an RLC network, Bode curves, a Nyquist locus and natural-frequency and Q equations.

Bode & Nyquist Analyzer for RC, RL and RLC Filters Analyze first- and second-order RC, RL and RLC filters with Bode and Nyquist plots from the same complex transfer function. Open the tool →

Connected CH3, CH2 and COOR blocks beside an NMR spectrum with multiplet peaks, an integration trace and a ppm scale.

Educational NMR Structure Builder – ¹H and ¹³C Spectra Build a simple structure and generate educational ¹H and ¹³C NMR spectra with integration, splitting and assignments. Open the tool →

Cross-section of an EI shell-type core with its two windows, the centre leg marked Ae and the winding around it, next to a window filled with round wire sections marked Acu and Aw.

EI Laminated Transformer Design Calculator Design EI laminated transformers: calculate core area, turns, wire sizes, window fill, losses, efficiency, and voltage regulation. Open the tool →

Section of an E ferrite core with the primary and secondary windings on the centre leg marked Np and Ns, next to a triangular flux waveform with the peak-to-peak swing marked ΔB.

Ferrite Transformer Design Tool: Push-Pull, Forward and Flyback Interactive tool for designing ferrite transformers for push-pull, forward and flyback converters, including losses, air gap and wire sizing. Open the tool →

RC low-pass schematic and magnitude response showing the −3 dB knee at fc and the −20 dB/decade slope, with the formula fc = 1 / (2π · R · C)

First-Order RC and RL Filter Calculator: Cutoff, Phase and Response Calculate first-order RC and RL filters, cutoff frequency, time constant, E12 values, gain and phase response. Open the tool →

Three-dimensional colored excitation-emission matrix showing fluorescence intensity, a selected excitation wavelength, and the corresponding extracted 2D emission spectrum.

Fluorimetry: 3D EEM and Emission Spectrum Explore a teaching EEM, choose an excitation wavelength and inspect the resulting emission spectrum. Open the tool →

Cover showing a periodic table colored by chemical family and an iron card with Fe symbol and electron configuration.

Interactive periodic table: properties, trends and element cards Interactive periodic table with properties, trends, radii, minerals, reactivity and detailed cards for all 118 chemical elements. Open the tool →

Cover showing connected CH3, CH2 and COOR blocks beside a simulated IR spectrum with absorption bands.

IR Structure Builder and Spectrum Simulator Build molecules from functional-group blocks, connect them and generate an educational IR spectrum with characteristic band assignments. Open the tool →

Schematic of an LM317 with R1 between output and adjust pin, R2 to ground and the adjust bypass capacitor, next to the output voltage formula, the minimum load condition and the power dissipation equation.

LM317/LM337 Adjustable Regulator Calculator: Voltage, Ripple, Current and Heatsink Design LM317 and LM337 supplies: calculate divider values, output tolerance, ripple, dropout, current limits and heatsink size. Open the tool →

Inverting operational amplifier with input resistor R1 and feedback resistor Rf, next to a gain-versus-frequency plot showing the flat gain Av and the roll-off beyond the cut-off frequency.

Operational Amplifiers Calculator Operational amplifier calculator for gain, bandwidth, slew rate, CMRR, offset, bias currents, integrators, and differentiators. Open the tool →

Technical cover showing a pH electrode in pH 7.01 buffer, a burette and an acid-base titration curve.

pH Buffer, Meter Calibration and Acid-Base Titration Tool Educational tool for pH buffers, pH-meter calibration, buffer capacity and interactive acid-base titration curves. Open the tool →

Schematic of a choke-input filter — rectifier, series inductor, shunt capacitor and load — next to the waveform before and after the filter and the equations for output voltage, critical inductance and attenuation.

Power Supply Filters: Choke Input, LC, Pi and RC Filters Calculate LC, pi and RC power supply filters: node voltages, ripple, resonance, critical inductance and startup transients. Open the tool →

Graetz bridge with smoothing capacitor and load, next to the rectified waveform showing the capacitor discharge and the peak-to-peak ripple

Rectifier and Smoothing Capacitor Calculator: Ripple, Diodes and Transformer VA Simulate rectifiers with smoothing capacitors to calculate DC voltage, ripple, diode stress, inrush, harmonics and transformer VA. Open the tool →

Four-band resistor coded yellow-violet-red-gold for 4.7 kΩ ±5%, above a logarithmic decade showing the E12 and E24 preferred values

Resistor Color Code and E-Series Calculator Decode resistor color bands, calculate standard E-series values, tolerances, ranges and the nearest commercial resistance. Open the tool →

Two resistors connected in series and two connected in parallel, with the formulas R = R1 + R2 and 1/R = 1/R1 + 1/R2, next to the resistor, capacitor and inductor symbols.

Series-Parallel Calculators: Resistors, Capacitors, and Inductors Calculate equivalent resistance, capacitance, and inductance for two components connected in series or parallel. Open the tool →

Balance with a solid solute, concentrated-reagent bottle, pipette and volumetric flasks beside mass and stock-concentration equations.

Solution Preparation Calculator Practical calculator for preparing solutions from solids or concentrated reagents using purity, density, assay and final volume. Open the tool →

Chain of three thermal resistances between junction, case, heatsink and air, above a cross-section of a device mounted with an insulator on a finned heatsink, next to the junction temperature and required resistance formulas.

Thermal and Heatsink Calculator: Junction Temperature, Plates and Pulsed Power Calculate heatsinks, junction temperatures, enclosure heating, homemade plates and pulsed thermal impedance for power electronics. Open the tool →

Wound toroidal core with the free hole marked and an inrush-current waveform, over the formula N = V / (4.44 · f · B · Ae)

Toroidal Transformer Design Calculator: Turns, Losses and Inrush Current Design toroidal transformers with turns, wire sizing, losses, regulation, remaining hole and inrush-current calculations. Open the tool →

Power transformer symbol with primary, centre-tapped high-voltage secondary and heater winding, beside a plot of B+ sagging as plate current rises

Tube Amplifier Power Transformer Calculator: B+, Heaters and VA Design a tube-amplifier power transformer from tube complement and B+ requirements, including heaters, rectifier, sag, bias and total VA. Open the tool →

Unmarked transformer with a few test turns and a millivoltmeter, next to a flux-density scale marked at 1.2 T, with the formula V/N = Vtest / Ntest

Unknown Transformer Identification Tool: Turns, Power and Rewinding Identify an unknown transformer safely: estimate turns, voltage ratio, flux density, VA rating, regulation and a new secondary. Open the tool →

UV-Vis spectrophotometer diagram with monochromator, colored beam, cuvette, absorption spectrum and calibration curve.

UV-Vis Spectrophotometry: Beer-Lambert Law and Calibration Curve Explore Beer-Lambert behavior, a UV-Vis spectrum and a calibration curve with wavelength, cuvette and concentration controls. Open the tool →

Zener shunt regulator diagram with series resistor, diode to ground, load and current and power equations

Zener Regulator Calculator: Resistor, Current and Power Calculate Rs for a Zener shunt regulator and check Zener current, Zener power and resistor dissipation across input and load limits. Open the tool →