CMOS 4047 Digital Clock Circuit

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This circuit provides a digital square wave that can be viewed directly or used to drive other circuits. It used the CMOS 4047 Low-Power Monostable/Astable Multivibrator. As used in Tom Duncan's Adventures with Digital Electronic's Book, to drive CMOS Decade of 4-bit binary counters.

RC = 10M x 100nF = (10x106) x (100x10-9) = 1 Hz

OscOut (Double Frequency of Q)
Q (Inverse of Q)

Q (Square Wave, Frequency RC Hz, 1:1 Mark:Space Ratio)

These 3 outputs can be viewed using an LED and 330R Resitor in series.

Low-power astable/monostable multivibrator 
with oscillator output.

 Cext |1  +--+ 14| VCC
 Rext |2       13| OSC
RCext |3       12| RETRIG
 /AST |4  4047 11| /Q
  AST |5       10| Q
  /TR |6        9| RST
  GND |7        8| TR
Resistor+LED soldered together