Max Amperage from 5V and 12V Molex Connectors

Hi folks,

We’re using both 4 pin molex connectors (I believe M506 and M507 are the correct names), to power other components.

We noticed, we can typically pull more power from one over the other. Are there different limits on these two power supplies? Is there anything that can effect one over the other - ie - too much draw somewhere else, could bring the limits down? In the documentation one was rated at 4A minimum (M506), vs the other (M507) rated a 7A regulated.


M507 is rather ‘isolated’ from impact to our Magni operation as separate regulators are used from main Magni key important power supplies. In a general way you are safest to use the AUX power from M507.

Where things get less specified is with use of the ‘MAIN’ power taps on M506. These powers are used both for MCB 5V and 12V for motor drivers. If you draw a lot from these it increases the risk of impacting MCB (Magni) operation and even causing resets on the Raspberry Pi.

Consider the ‘MAIN’ power outputs as something we included for general usage at a time of lower power Raspberry Pi 3 usage and felt ‘Why not supply this but for lower currents’.

So YES there is higher risk in use of Main Power as it could impact or even reset the raspberry Pi.

We do not have ‘rocket science’ specified max currents for the MAIN power jack as the Pi4 as well as our own Magni motor driver currents vary such a great amount is it next to impossible to ‘spec’ the max currents on the ‘Main’ jack, M506.

The other issue is both the AUX as well as the Main power jacks are fed by separate 5V and 12V on-MCB supplies that are buck converters. Instantaneous high current usage such as from 0 amps to max specified have not been characterized for how much of a drop out you may see.

The place we discuss the currents are as follows:

Should you find errors in any of the above we appreciate any corrections.

Thank You, Mark

Thank you Mark for this response.

I can confirm M506 appears to be the “more” stable power (or at least allows more current to be drawn from), than M507.

Does this make sense?


Sorry for long delay Kris, I have been ‘distracted’.

Offhand I would say AUX power (right jack when looking at top of the MCB, M507) should get you more safe power and again, drawing lots of power especially in a ‘pulsed’ way from M506 (left jack when looking at top of the MCB, M506) on 5V brings a stronger chance of disrupting the Pi host CPU.

Thus your report is not what I would have expected.
If you supply me some numbers for the sort of current you wish to source for each power supply (5V is separate then 12V) this may help.

Also tell me if these MCB boards a very current because we were forced to source a different inductor that is more ‘silver’ and ‘shorter’ than the old black ones due to some supply issues. The silver inductors are about 8mm square and a shorter 5mm tall and are used on both of the 5V power supplies (Main and Aux). Is your concern 12V or 5V mostly? Boards made in 2022 will use identical black symetrical cube inductors saying C472 on top in silver.

A serial number from a board you are seeing ‘weaker’ power delivery capabilities and if it is 12V or 5V would better help me study this issue.