A circuit inspired by the NE555, built entirely with transistors, resistors, capacitors, and diodes, becomes a test bench for the SPICE simulator I am developing on my server.
GX-TXT-v3 testing shows how pulse count affects HOLD-node charging, LED turn-on threshold, and indication time.
GX-TXT-v3 sensitivity and threshold testing, following QIN, HOLD and orange LED behavior across gain and sensitivity settings.
GX-TXT-v3 testing with a virtual photodiode: VIR measurements, preamplifier gain, probe loading and LTspice comparison.
GX-TXT-v3 DC bias measurements, current consumption and NE555 timer verification compared with LTspice simulation.