system advice needed?

[Superdad]

1 hour ago, the_doc735 said:

many thanks for saying that the minimum mA IS NOT 280 (i.e. "NO"). However I am not able to work with your explanation, so I can't work this out correctly. Very Sorry! However your website does state that you supply a 2.9A SMPS with the Iso Regen, so I guess I'll have to work with that figure? Cheers!

 

I guess I am not sure what your confusion is.  The ISO REGEN draws 240mA (that’s 0.24 amps) through its DC input jack.

The USB 2.0 specifications allows for devices (DACs, keyboards, bus-powered drives, headphone amps, whatever) to draw from the host a maximum of 0.5A.

So assuming you had a device attached to the ISO REGEN that drew the full allowed 500mA, then you would need to be powering the ISO REGEN with a supply capable of 740mA (0.74A).  Thus a 1A power supply would be fine.

(We had other reasons for the included SMPS to be one that is rated at 2.9A, but it is not because of current draw.)

I hope that clears things up for you.

Cheers,

—Alex C.

[the_doc735]

18 minutes ago, Superdad said:

 

I guess I am not sure what your confusion is.  The ISO REGEN draws 240mA (that’s 0.24 amps) through its DC input jack.

The USB 2.0 specifications allows for devices (DACs, keyboards, bus-powered drives, headphone amps, whatever) to draw from the host a maximum of 0.5A.

So assuming you had a device attached to the ISO REGEN that drew the full allowed 500mA, then you would need to be powering the ISO REGEN with a supply capable of 740mA (0.74A).  Thus a 1A power supply would be fine.

(We had other reasons for the included SMPS to be one that is rated at 2.9A, but it is not because of current draw.)

I hope that clears things up for you.

Cheers,

—Alex C.

yes! many thanks! ~ I did think that nearly 3A for an Iso Regen seemed a bit too much! (LOL). 1A is much more realistic! Very grateful for your assistance. Best Wishes. Doc.

[barrows]

I also think we should consider some devices which might, in worst case scenarios, be hooked up to a USB output which draw more than 500 mA (despite the USB spec).  For example, the Chord Mojo charges its battery via a USB cable.  When one is charging it, it draws close to 1A!  So although an extreme case, I can see a customer trying this at some point without realizing that it could be a problem.

Yes, that is an extreme and unusual case, but I am sure there are a few customers who may do this.

[Superdad]

2 hours ago, barrows said:

I also think we should consider some devices which might, in worst case scenarios, be hooked up to a USB output which draw more than 500 mA (despite the USB spec).  For example, the Chord Mojo charges its battery via a USB cable.  When one is charging it, it draws close to 1A!

 

Yep.  That’s why the dedicated 5VBUS regulator in the REGENs (and in the Rendus) is a 1A capable part. 

[the_doc735]

6 hours ago, barrows said:

I also think we should consider some devices which might, in worst case scenarios, be hooked up to a USB output which draw more than 500 mA (despite the USB spec).  For example, the Chord Mojo charges its battery via a USB cable.  When one is charging it, it draws close to 1A!  So although an extreme case, I can see a customer trying this at some point without realizing that it could be a problem.

Yes, that is an extreme and unusual case, but I am sure there are a few customers who may do this.

good job I don't have a chord mojo (LOL)

[barrows]

45 minutes ago, the_doc735 said:

good job I don't have a chord mojo (LOL)

Right, but many people read these forums, so it is important to address all possible uses when giving out specs on power draw etc.

[Pietro]

Guys ,

 

I found a battery who is perfect for Chord Mojo !!! The battery is for Olympus foto cameras and is cold BS 5 !!!  Is 2000 mA battery and 7.8 V and is match perfectly inside the Chord Mojo !!!! Best wishes !!!

Pietroj