#amplifier

Bipolar-junction-transistor (BJT) circuit maths as an API, computed locally and deterministically. The currents endpoint relates the three terminal currents through the DC current gain β (hFE): the collector current Ic = β·Ib, the emitter current Ie = (β+1)·Ib and the common-base gain α = β/(β+1) ≈ 1, from β and any one current. The bias endpoint analyses the operating point of the classic voltage-divider bias network — from the supply voltage, the two divider resistors, the collector and emitter resistors, β and the base-emitter drop it computes the Thévenin equivalent (Vth = Vcc·R2/(R1+R2), Rth = R1‖R2), the base current Ib = (Vth − Vbe)/(Rth + (β+1)·Re), the collector and emitter currents, the collector-emitter voltage Vce and the node voltages, and classifies the operating region as cutoff, active or saturation. The power endpoint computes the transistor's power dissipation, Pd ≈ Vce·Ic (plus Vbe·Ib), to check it against the rated maximum. Currents are in amperes, resistances in ohms and voltages in volts, with Vbe defaulting to 0.7 V for silicon. Everything is computed locally and deterministically, so it is instant and private. Ideal for electronics, amplifier-design, embedded and hobbyist app developers, biasing and operating-point tools, and electronics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is BJT biasing; for op-amp circuits use an op-amp API and for an LED series resistor an LED-resistor API.

api.oanor.com/transistor-api

Operational-amplifier gain and bandwidth maths as an API, computed locally and deterministically. The gain endpoint computes the closed-loop gain of an inverting (Av = −Rf/Rin) or non-inverting (Av = 1 + Rf/Rin) amplifier from the feedback and input resistors, gives the gain in decibels (20·log₁₀|Av|) and the output voltage for an input, and solves the feedback resistor needed for a target gain. The summing endpoint computes the output of an inverting summing (adder) amplifier, Vout = −Rf·Σ(Vi/Ri), from any number of weighted inputs — the basis of analogue mixers and digital-to-analogue converters. The bandwidth endpoint applies the gain-bandwidth product, GBW = closed-loop gain × bandwidth, and solves any of the three (a 1 MHz op-amp at a gain of 10 has a 100 kHz bandwidth), and computes the full-power bandwidth from the slew rate and the peak output voltage, f = slew_rate/(2π·Vpeak). Everything is computed locally and deterministically, so it is instant and private. Ideal for analogue-electronics and circuit-design tools, amplifier, filter and sensor-conditioning design, audio and instrumentation apps, and electronics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is op-amp amplifier design; for Ohm's law, reactance and resonance use an Ohm's-law API.

api.oanor.com/opamp-api