DIGITAL_CONTROL_OF_PHASE_ANGLE

Published:2009/7/6 1:16:00 Author:May | From:SeekIC

Circuit transforms 5-bit digital control word into phase angle over full range. Resolution is proportional to length of control word. Developed for stage lighting control. Z1C serves as clock oscillator that is periodically synchronized with zero crossings of AC line; R1 and C1 set clock frequency, which for 5-bit control word must be 64 times line frequency or 3.84 kHz. Load requirements determine choice of triac for Q4. Required signal for generating triac drive is produced by D1-D4 and Q1.-R. Tenny, Circuit Provides Digital Phase Control of AC Loads, EDN Magazine. Oct. 5, 1977, p 99-101.



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