Main PCB assembly
1.
Solder the diode and all resistors
2.
Solder all three IC sockets
3.
Solder the non elecrolytic capacitors
4.
Solder the 78L05
–
watch the polarity!
5.
Solder the box power header. Make sure the notch lines up with the screenprint
legend. If in doubt, have a look at a power cable, and make sure when inserted into
the header the red stripe lines up with the -12V screenprint.
6.
Solder all electrolytic capacitors and the trimmer
7.
Cut male headers to size and solder them into place. Make sure that they stick out of
the bottom of the PCB.
Main PCB minor modification
Chronograf puts out a reset pulse when Start/Reset is pressed.
We realised that for some applications it would be useful
for Chronograf to also put out a reset pulse when Stop is
pressed. It
’
s an easy mod, just add a 1N4148 diode as shown
to the rear of the PCB. We recommend that you perform this
mod when building your Chronograf. Later versions of the PCB
will include the mod, and will state
‘
No mod needed
’
on the
back of the PCB.