Help identify power components

[ukspawn]

this is what i see reading what Kellys_Eye said.

 

[Martaine2005]

Yes, you are correct.
I wanted to make sure you understood that the common is very important here. Common and -12V = negative 12V. Common and +12V = positive 12V.
If you only used -12V and +12v you would have 24V.
AAs are 1.5V not 3V. So 8x1.5=12.

Martin

 

[ukspawn]

oh DUR. of course theyre 1.5 lol, i totally understand now lol

Sorry my bad

 

[ukspawn]

i have found another alternative i think. does it matter if the old is a 25w PSU and the NEW is 40w , i assume not as it doesnt with PCs,
the PSU wont "force" more power than is drawn, is that right?


does this meet the correct spec? https://www.mouser.co.uk/datasheet/2/632/DS_AB40S_D-1858813.pdf

Nevermind you have to order 50 of those

 

[Martaine2005]

FWIW, it makes no difference. The device will only use the current it needs.

Martin

 

[ukspawn]

FWIW, it makes no difference. The device will only use the current it needs.

Martin

Yes I thought so, Thanks.

In PC Builds we say go above what you need, so if you need about 500 watts then go for a ~800watt psu.
I dont think you need so much headroom in a component as 'static' as a DAC, i would assume its always the same voltage everywhere except the output voltage. its not even an amplifier, just a DAC and volume control basically. But I did wonder if using a higher rated would be better in terms of a 40 watt PSU is probably built to handle more heat and with more headroom, so running cooler = longer life... but then i considered efficiency and isnt there a sweet spot for PSU to operate efficiently...

Anyway, thanks. just thinking out loud, maybe its interesting

 

[kellys_eye]

Not quite. That will be 24V.
You forgot the 0V centre connection.
But I think you understand.

No, he didn't get it wrong - you misread his post and missed the bit where he stated the common connection would be ground....

to the OP - yes, with two 12V batteries connected as described the common point is the ground and the two 12V posts remaining will be + and - 12V.

 

[kellys_eye]

Please use either current limiting or place an inline fuse in the 12V rails - 2A fuses will suffice. FAilure to do so could result in massive damage if there is a short elsewhere in the circuit.

 

[Martaine2005]

No, he didn't get it wrong - you misread his post

Quite possibly. Certainly wouldn’t be the first time.
But I did clarify in post #42 to make sure the OP understood.

Martin