Optical Pulse Generator

This little aid was originally designed to test the Shutter Time Meter from the January 2006 issue. This meter was specifically designed for ‘analogue’ SLR cameras.
In order to measure the exposure time of a camera accurately, it will first have to be checked with a well-defined signal first. This circuit was designed for that purpose. But the circuit can also be used if you need a well-defined pulse for some other purpose.

Resistors

R1 = 1k

R2,R3 = 1M

R4 = 10k

R5 = 180

Capacitors

C1,C2 = 33pF

C3 = 10nF

C4,C5,C6 = 100nF ceramic, lead pitch 5mm

Semiconductors

D1 = HSDL-4230

IC1 = 74HC4060

IC2 = 4518

IC3 = 74HC4017

Miscellaneous

S1 = pushbutton, make contact, 6mm

J1,J2 = 3-way pinheader with jumper

X1 = 4.096MHz quartz crystal 1 wire link.

PCB, ref. 064006-1