resistance which reduces any unwanted voltage drops as return currents travel through the
wiring.
This can be done in a variety of ways but one useful and simple method involves having a
4mm banana socket mounted near each power supply. The banana socket is then connected to
0V, using the dedicated 0V screw terminal, on the PSU board. Use at least 24/0.2 wire to
make this connection.
If both the power supplies have a banana socket then it is a simple matter of patching the two
modular cases together with a banana patch lead. The great thing about bananas is that they
are stackable so it's easy even if you have more than two cases to connect up.
I recommend that you use thick multistrand cable to make your grounding leads and that you
use good quality 4mm banana sockets and plugs.
The dedicated 0V screw terminal on the PSU board has been connected first to a bonding point which
grounds the panel. The bonding point then connects to a 4mm banana socket on the left. Thus both the
metal panel and the banana socket have a good connection to the PSU's 0V.
To reduce electrical noise it is wise to ground the panel on which the power supply is
mounted. In Oakley PSU versions prior to issue 4 the lower left mounting hole of the PCB
was connected to 0V. Simply mounting the board to the panel with metal screws would
connect the PSU's 0V to the panel. Recently I learnt it was necessary to make this connection
more robust and with a lower overall resistance. Thus the issue 4 board removes the grounded
mounting hole and adds the solid screw terminal that connects directly to the 0V close to the
output terminals of the PSU.
To make a bonding point is straightforward. Simply drill a 4mm hole in your panel. Scrape
back around the hole any finish on the inside surface, such as paint or anodising, to reveal the
shiny metal underneath. Fit an M4 screw from the front and pop on a toothed star washer and
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