65 lines
2.2 KiB
JavaScript
65 lines
2.2 KiB
JavaScript
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import { describe, it, expect } from 'vitest';
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import { Circuit, Resistor, VoltageSource, Capacitor } from '../src/index.js';
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describe('RC transient — charging curve', () => {
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it('V(τ) ≈ 63.2% of V_source (R=10k, C=100µF, V=5V)', () => {
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const R = 10000;
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const C = 100e-6;
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const V = 5;
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const tau = R * C; // 1s
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const circuit = new Circuit();
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circuit.addComponent(new VoltageSource('V1', 'vcc', 'gnd', V));
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circuit.addComponent(new Resistor('R1', 'vcc', 'out', R));
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circuit.addComponent(new Capacitor('C1', 'out', 'gnd', C, 0));
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const dt = 0.005; // 5 ms
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const samples = circuit.runTransient(tau * 3, dt, 10);
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// Find sample nearest t = τ
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const target = samples.find(s => Math.abs(s.t - tau) < dt);
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expect(target).toBeDefined();
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const Vt = target.nodeVoltages.out;
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const expected = V * (1 - 1 / Math.E);
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expect(Vt).toBeGreaterThan(expected * 0.95);
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expect(Vt).toBeLessThan(expected * 1.05);
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// Final value ≈ V
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const last = samples[samples.length - 1];
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expect(last.nodeVoltages.out).toBeGreaterThan(V * 0.90);
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});
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it('5τ reaches > 99% of V_source', () => {
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const R = 1000;
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const C = 1e-6;
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const V = 3.3;
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const tau = R * C; // 1 ms
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const circuit = new Circuit();
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circuit.addComponent(new VoltageSource('V1', 'vcc', 'gnd', V));
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circuit.addComponent(new Resistor('R1', 'vcc', 'out', R));
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circuit.addComponent(new Capacitor('C1', 'out', 'gnd', C, 0));
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circuit.runTransient(5 * tau, tau / 200);
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expect(circuit.nodeVoltage('out')).toBeGreaterThan(V * 0.99);
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});
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});
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describe('RC transient — discharge', () => {
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it('capacitor pre-charged to 5V discharges through R', () => {
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const R = 10000;
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const C = 10e-6;
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const tau = R * C; // 0.1 s
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const circuit = new Circuit();
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circuit.addComponent(new Resistor('R1', 'out', 'gnd', R));
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circuit.addComponent(new Capacitor('C1', 'out', 'gnd', C, 5)); // pre-charged
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const samples = circuit.runTransient(3 * tau, tau / 100, 10);
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// V(τ) ≈ 5 · 1/e = 1.84 V
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const atTau = samples.find(s => Math.abs(s.t - tau) < 0.002);
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expect(atTau.nodeVoltages.out).toBeGreaterThan(1.5);
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expect(atTau.nodeVoltages.out).toBeLessThan(2.2);
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});
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});
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