USR PUBLISHER

Manual fan regulators require physical access and rely on mechanical contacts. This paper presents a low-cost infrared remote-controlled regulator for a tapped single-phase AC fan using two NE555 timers, a CD4017B one-hot counter, a 38 kHz infrared receiver, optotriac isolation, and TRIAC switching. The supplied prototype was re-engineered into a calculation-verified design while preserving its discrete, firmware-free architecture. The transmitter timing network was corrected to R_A = 1 kΩ, R_B = 18 kΩ, and C = 1 nF, which gives a calculated carrier frequency of 38.9 kHz and a duty cycle of 51.4%. Receiver command conditioning uses R = 100 kΩ and C = 10 µF, which gives a 1.10 s pulse. The full-wave supply analysis was corrected for 50 Hz mains, and a 4700 µF reservoir capacitor is recommended to control ripple. The CD4017B provides four deterministic states: OFF, low, medium, and high. Analytical plots quantify carrier detuning, monostable timing variation, and supply ripple. Functional observations in the source report approximately 10 m line-of-sight operation and about 1 s response. The design offers low component cost, electrical isolation, repairability, and no dependence on software or internet services. Its present limitations include the absence of coded addressing, closed-loop speed feedback, harmonic measurements, motor speed data, and long-duration thermal tests.