CMOS_KEYER_2

Published:2009/7/11 3:22:00 Author:May | From:SeekIC

Gives variable speed, automatic spacing, and self-completing dots and dashes.Gates C, B, and Aform gated MVBR Dot paddle initiates dot by making output of gate D go low, while gate E goes low for dash. Character-shaping section (gates G, H, and F with JK flip-flops FF1 and FF2 takes square pulses from pin 3 of MVBR gate B and gives perfectly spaced dots and dashes. FF1 divides clock pulses by 2, making dot equal to one complete period of MVBR. FF2 divides output of FF1 by 2, and outputs of both flip-flops are logically ORed to provide dashes. K1 is SPST reed relay. Supply can be 9-V battery.-T. R. Crawford, A Low-Power Cosmos Electronic Keyer in Two Versions, CQ, Nov. 1975, p 17-24.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/CMOS_KEYER_2.html

Print this Page | Comments | Reading(3)