ADDAC200RM RAILS MONITOR USER’S GUIDE
June.2024
Revision.01
Welcome to:
page 2ADDAC SYSTEM
DESCRIPTION
ADDAC200RM allows a simple and straight forward way to
monitor the voltage of your system. A 0.1% precision analog
voltage meter shows the status of both +12V and -12V rail.
EURORACK ±12V POWER RAILS
Although we all refer to Eurorack PSU voltages as +12V and
-12V this is hardly ever the case, although most systems
operate at close proximity to this ideal reference, there are
situations where the drop from the ideal voltage is large
enough to influence the performance of your system.
PSU CURRENT RATINGS
Running a PSU too close to it’s limits will always cause more
stress to the PSU, a good practice it to use only about 75% of
your PSU maximum ratings, this will greatly extend the PSU
life.
PSU VOLTAGE DROPS
PSUs will show a small voltage drop as current increases
which will drastically increase when pushed closed to it’s
limits. Heat will also influence this drop, heat is related to the
current drawn, as more current is being drawn more heat will
build up on the PSU, heat conditions will reduce the maxi-
mum ammount of current that can be dellivered by the PSU.
While the current consumption drop is somewhat stable and
immediate (as you turn the frame on the current consumption
will stabilize in a few seconds) the heat drop will take some
time to occurr, heat will build up over time until it stabilizes
and only if it has “headroom” to stabilize. If heat dissipation is
not effectice than the drop will continue until it reaches a
balance point which can be several volts below our 12V
reference. At this point your PSU will be under great stress
and the heat generated is prone to leave some permanent
scars.
Heat will start to have an impact at about an ambient
temperature of 50 degrees celsius, at 70 degrees the maxi-
mum current rating will drop by 50%. If your PSU is rated at
2A maximum and it’s running at 70 degrees then it will only
be able to delliver 1A maximum.
For the PSU this is a complex balancing act as current influ-
ences heat and heat influences the maximum ammount of
current available which all together influences the voltage
drop.
This is why it’s so important to keep the PSU load at a
sensible level.
Tech Specs:
4HP
3,5 cm deep
60mA +12V
60mA -12V
Positive Rail
Over Voltage
Problematic Voltage
Acceptable Voltage
Over Voltage
Negative Rail
Problematic Voltage
Low Voltage
Low Voltage
Acceptable Voltage
