Calculadoras

Calculadoras de electrónica gratuitas, con la fórmula, un ejemplo resuelto y el esquema: ley de Ohm, resistencia para LED, NE555, filtros y más.

Esenciales

• Component color codesO introduce un valor para obtener los colores (4 bandas):
• Divisor de corrienteTwo parallel resistors split an incoming current in inverse proportion to their resistance — the smaller resistor carries the larger share.
• Resistencia en serie para LEDNadie conecta un solo LED. Cada rama es su propia cadena en serie de LED detrás de su propia resistencia — poner más LED en la cadena aumenta el margen…
• Ley de OhmRellena dos valores cualesquiera — el tercero se completa automáticamente.
• Serie / paraleloSerie:
• Divisor de tensiónA load draws current from the divider's midpoint, which pulls Vout down from the unloaded (ideal) value — the classic "why did my sensor reading change…

Redes de resistencias

• Calculadora de combinaciones de resistenciasNecesitas un valor que la serie E no ofrece. Esta herramienta encuentra la resistencia estándar más cercana y las mejores combinaciones en serie y en…
• Relación de resistencias— or with "Invert" ticked.
• Transformación estrella / triánguloSome networks — a Wheatstone bridge with a load across the middle is the standard one — have no two resistors in plain series or plain parallel, so the…
• Thévenin / NortonAny linear source, however many parts are inside it, behaves at one pair of terminals exactly like a voltage source behind a series resistance — or, just…
• Puente de WheatstoneEach half is its own divider, and the output is the difference between their midpoints:

Componentes

• Resistencia de base de un BJTUn transistor usado como interruptor no es un amplificador — desperdicias su ganancia a propósito. El error es dividir la corriente de carga por la hFE…
• Control de puerta MOSFETA MOSFET draws no steady gate current, so holding it on is free — but every edge has to shovel the whole gate charge in and back out again, and is real…
• Termistor NTCBeta-model resistance of an NTC at any temperature (T in kelvin), plus the divider voltage an ADC would read.
• Resistencia pull-upmantiene el driver dentro de su corriente de absorción nominal, y mantiene la línea liberada por encima del umbral de entrada.
• Decodificador de marcas SMDDos o tres caracteres en un encapsulado de 2 mm de largo, y ningún carrete con el que comprobarlos. El código de una resistencia es aritmética real —…

Filtros y temporización

• Resonancia LCAt that frequency the two reactances are equal — — and the branch currents cancel, so this parallel tank presents its highest impedance.
• Temporizador NE555Red de temporización completamente cableada — los pines están agrupados por función, no por el orden físico del DIP (consulta la entrada del temporizador…
• Filtro RC— el punto de −3 dB, donde la salida ha caído al 70.7 % de la entrada. R en serie, C a tierra: la impedancia de C baja al subir la frecuencia,…
• Reactance (capacitive / inductive)Capacitive: — reactance falls as frequency rises, so a capacitor passes high frequencies.
• Filtro Sallen-KeyA unity-gain second-order low-pass: sets where it turns, sets the shape. Q is peaking, not frequency — 0.707 is flat to the corner, below that the…
• Constante de tiempoRC: — RL: — una constante de tiempo es lo que tarda el circuito en recorrer el 63.2 % de la distancia que le queda hasta su valor final.

Digital y MCU

• Conversor de pasos ADCWhat one count is worth, and how counts and volts map onto each other, using the common Arduino-sketch convention where full scale is the top count,…
• Crystal load capacitorsA crystal's datasheet states its load capacitance Cₗ. The two caps sit in series as seen by the crystal, and the board adds stray capacitance Cₛ (~3–5 pF…
• Bases numéricas y bitsUn mismo valor mostrado a la vez en binario, decimal, hexadecimal y octal, con cada bit pulsable. Leer 0x2A es aritmética; ver 00101010 con los bits 5, 3…
• Resolución PWM / temporizadorA hardware timer counts clock ticks through a prescaler up to TOP, then wraps: . Those TOP + 1 counts are also the duty steps: . Bigger TOP = finer…
• Error de baudios UARTA UART divides the MCU clock by an integer: , where OSR is the oversampling factor chosen below. That rounding is the whole source of the error: under…

Amplificadores, audio y RF

• Conversor de tensión alternaSe supone onda senoidal. — —
• Longitud de antena— the element is then a fraction of that wavelength, trimmed by a shortening factor k: for a quarter-wave. Two things trip people up. A λ/4 whip is…
• Conversor de decibeliosVoltage: — Power: . Power goes as voltage squared, which is the whole reason for the 20 against the 10. A bench dB question is usually absolute, not…
• Amplificador operacionalNon-inverting: — Inverting:
• Slew rate y ancho de bandaFull-power bandwidth: — the highest frequency at which the op-amp can still swing the whole amplitude. Past it the output stops following and simply…
• Speaker crossover (1st order)A series capacitor keeps the lows out of the tweeter; a series inductor keeps the highs out of the woofer. First order = 6 dB/octave each side, crossing…

Fuentes de alimentación y baterías

• Duración de la batería— la eficiencia se introduce como porcentaje y se aplica como fracción.
• Shunt de medida de corriente— but the sense voltage is the real decision, because it alone fixes the heat: , with R cancelling out. 100 mV at 10 A is a full watt no matter which…
• Convertidor DC-DCand . Continuous conduction with ideal switches — a real design lands a few percent higher on duty once the switch and diode drops are counted.
• Decoupling capacitorA reservoir close to the chip supplies the current the rail cannot deliver fast enough: , and the capacitor's own must stay below or it drops the…
• Almacenamiento de energíaCapacitor: — Inductor:
• Snubber RCTwo-measurement method. You are giving the ring as the scope sees it, then again with a known capacitor clipped across the switch. comes out of the two…
• Regulador de tensión— the zener must stay reverse-biased with Iz > 0 to regulate.
• Regulador Zener en derivaciónA zener holds the output at by swallowing whatever current the load leaves behind, so the series resistor is sized by the worst corner and never by the…

PCB, cableado y calor

• AWG ↔ mm²El calibre es geométrico, no una tabla de consulta: mm, y . La resistencia supone cobre a 20 °C.
• Impedancia controladaA trace over a single reference plane, solved backwards from IPC-2141's own closed-form approximation: . Good to a few percent for 0.1 ≤ w/h ≤ 2 — the…
• Disipador / térmica— the heatsink only gets what is left of the budget after the package and the interface have taken theirs.
• Capacidad de corriente de pistas PCBEmpirical IPC-2221 formula — a design estimate, not a manufacturer guarantee.
• Caída de tensión en cables, where for a round trip. The ohms per metre come from the AWG table.