‘FunKlock’
Issue 5 (14 November 2019)
www.pvelectronics.co.uk
- 17 -
4.13 R16, R17 (390 KΩ)
AM, PM (4mm neons)
Use small pieces of the clear insulation provided, on the leads of
the 2 neons to prevent shorts. You can make a test fit of the IN-12
tubes to help you decide the best height from the PCB for them.
The insulation is actually heat-shrinkable, so for a very neat finish
you can gently blow with hot air to shrink the insulation after
soldering the neons in place.
4.14 Tube Test
The clock is now ready for final powering up. Insert 4 IN-12 or
other compatible tubes into the tube sockets. If you look inside the
tubes, you can see the correct orientation of the digits. Insert the 4
tubes and THEN assemble the 2 PCBs together, ensuring the 4
LEDs go into the holes in the tube PCB.
Power up the PCB with a 12V DC supply (centre positive). Take
great care not to touch live parts on the PCB.
If all is well, the tubes should all count 0..1..2......9 repeatedly.
Pressing the SET button will exit from the tube test and the clock
will start showing the time.
If this does not happen, remove power immediately and check your
work carefully.
