Choosing the right sized Power-Brick for your modular system doesn’t need to be hard.
If you aren’t sure how much current your modules will draw, then we recommend allocating approximately 1A of Brick-Current for each row you wish to power. The small sized “Tornado” brick, for example can deliver up to 6A of Brick-Current, so would probably be fine for up to 6 rows.
In the real world different modules draw different amounts of current. Some systems might need 4A Brick-Current per row, whilst others only need 0.4A
To calculate your brick needs, first we need to distinguish the difference between what we will call Brick-Current and Output-Current.
Brick-Current is the current from the 15V Power Brick going into the Busboards.
Output-Current is the current going out of the Busboards at different voltages into your modules (+5V, +12V and -12V).
Brick-Current and Output-Current do not match each other exactly, but Output-Current on the +12V and -12V rails will be approximately equal to their Brick-Current, whilst output current on the +5V rail will be equal to approximately half the Brick-Current.
5.4A on the +12V rails will draw approximately 5.4A Brick-Current
2.5A on the -12V rails will draw approximately 2.5A Brick-Current
1.6A on the +5V rails will draw approximately 0.8A Brick-Current
The total Brick-Current on this system would be approximately 8.7A.
To estimate your total current needs, you can build a virtual rig on Modular Grid which will then tell you the total output current. It’s a good idea to have a brick that can deliver more than what you need.
This will allow your system to remain flexible and reduce heat in your brick.
Please note however that the Hurricane brick needs to put out at least 2A of Brick-Current if you want to avoid busboard vibration. This busboard vibration will be audible as a slight ringing sound physically coming from the busboard them selves, but does not transfer to the audio path in your modules.