Power consumption question

Hermod+
1

Hi there @squarpadmin !

Great work on the new module. It seems that powering the pyramid via the hermod would yield a combined current draw of 1320mA. Have you tested this on an intelljel stealth case loaded up with modules on the +/-12V rails (purported max of 5V rail on the 80watt TPS supply is 1500mA)? I’m curious if it would introduce any noise, or if power-on spikes are an issue…

Thank you for your work!

2

Hi @tehnir

  1. Are you talking about Hermod or Hermod+ ?
  2. How did you end up with 1350mA? It seems excessive. If we’re only talking about the +12V rail, it should stay well within 1000mA.
  3. Pyramid does not really draw 500mA, it’s just using a regular USB power supply, which specifies a nominal power capacity of 500mA. I don’t have exact numbers to give you, but it should be well below that.
  4. Hermod, particularly with a USB device plugged in, can introduce some noise into the power rail. Your mileage may vary, as it is really dependent on the overall system, other modules, the power supply, etc. Hermod+ has a much more refined power circuitry which greatly reduces this.
  5. USB devices can sometimes cause power-on spikes, yes. Pyramid should be pretty reasonable, and if we’re talking about Hermod+, its power circuitry also helps in that regard.

Let me know if I can be of any more help

1 Like
3

Hi @Thibault - thank you for your reply. My replies inline below:

  1. Hermod+
  2. 500 + 820 (as of tonight), the number currently listed on modgrid
  3. ah I see; thank you for clarifying
  4. "
  5. awesome! ^___^
4

Ah, my bad, on the 5V rail, that is correct.
Using the Intellijel Stealth Case, you might want to stick with using the 12V rail, with has a much higher power budget.

@tehnir You might know the following, I’m just writing this for potential future readers:
For the record, Hermod+ has a switch, which sets the 5V power source. It can either be the 5V rail of the PSU, or using an internal power regulator which uses the +12V rail as input and outputs 5V.

1 Like
5

ah ok, so if I hook up the pyramid to the hermod+ as host with the power switched to +12V rail, does the extra amperage of the pyramid get drawn from the 5V supply of the case, or the generated 5V of the module? I apologize if this question is silly; I just hadn’t understood that modules can generate their own power sources.

6

Not at all!

If the power switch is set to use the +12V rail, the +5V rail won’t ever be used by the module. It might as well not even exist which is the case for some power supplies).

Long story short, the extra power required by Pyramid will be drawn from the +12V rail.
In this configuration, plugging a USB device into the HOST port of Hermod+ should only add up to an extra +200mA consumption on the +12V rail (that is, if the device is compliant with USB power specifications)

1 Like
7

okie! :slight_smile:
I will assume that pyramid mk3 will draw around 200mA and that it is compliant. Good to know this info for other devices I might consider.

8

Sorry to bring up this ghost topic, but this seemed like the most relevant thread.It seems I may have answered my own question already, but maybe this can help someone else, or maybe I’ve answered my own question incorrectly and someone else can chime in and correct me :laughing: .

Question: When running the Hermod+ in 5v mode per the instructions: “Make sure the +5V rail can supply 600mA minimum for powering Hermod+ (and add +500mA maximum when attaching a controller on USB host).” My question is around the phrasing of the second part of the statement for the “controller on USB host”. It was unclear to me if this meant by using the 5v mode if the Hermod+ automatically sets aside 500mA for the usb Host port, or if this just meant it can provide up to 500mA over this port.

I understand the Hermod+ requiring a known 600mA on the 5v rail, but the additional “+500mA maximum” language confused me as this seems like it should be determined based on the specific usb device draw. I now believe what this statement is just trying to convey is that in 5v mode, the Hermod+ can provide up to 500mA to the device being powered/recieving midi from the USB host port, but obviously limited by what your power supply has left after the Hermod+ ~600mA use.

  • The USB device I am using connected directly to the Hermod+ via the host port only draws around 240mA.
  • My power supply specs (Pod26) are:
    -12v: 0.28mA
    +12v: 0.7mA
    +5v: 1.0mA

I opened the Hermod+ while writing this question and realized I had changed it to 5v mode some time ago (before adding the USB device), and it has been running completely fine- which seems to answer my question. I am planning to add another module to my pod case, so knowing I’ve got most of the +12v available solves my potential issue if the Hermod+, usb host, and new module were all sharing the +12v 0.7mA rail.