AC Powersupply

[Screaming_Rabbit]

Hello

I have a few external powersupplies for external LACIE FireWire Harddisks.

Specifications:

DC Output:  5V  2.0A / 12V  2.2A

I think it's regulated, since it's for a HD. How can I find out?

... and is this enough power to run 3 fully equipped MidiBox LCs, or should I better use one for each core/LC module?

Thanks and greets

Roger?

[Steven_C]

measure the output... if it is unregulated, the voltage will be higher than the rated value, when there is no load. When you put a load on it, an unregulated psu's voltage reading will go down. A regulated PSU will always read the rated voltage value, unless you try to draw more current than it is designed for, in which case the voltage will go down.

I use a 1.6A PSU for one midibox LC, and that is barely enough current... but that is powering both the MF circuit, and everything else as well.

Use the 5v, 2A output for two LC cores, din, dout, ain, etc, and the 12V 2.2A output for 16 MF's, maybe, but I think you won't get 24 channels from one PSU without problems.

Maybe share one such PSU between two LC's and the third LC can have it's own! (2 PSU's between 3 boxes total)

BTW, building 3 LC's is no easy task I must warn you! (Originally I wanted to build 2 LC's, but have given up at just 1... lots of work and planning!)

Good luck, from Steve

[Screaming_Rabbit]

Thanks Steve

... for your very informative response! ... and for your warnings.

The 3 LCs are my target. I know it's a lot of work (planning, testing, evaluating and so on) and it won't be easy for a newbie like me. I will start small with a MidiMon. After finishing this I will build me one or more  testing-boards to play and test different setups as well as getting more confortable with the programming (learning by doing).

The realisation is the last step when the boards are working and I'll take my time to do it (I hope MIOS is still working under the PIC 18F452 by then  :-/ )

Did you give up because of the amount of work or caused by problems?

About the Power Supplies:

I have 6 pieces and with your information, I'll take one for every core and MF Module (if they're regulated... have to check first). I'll build the 3 PSUs into a 1U 19" Rack (external) and connect them with a multicore cable. Is it better to connect them isolated (1 PSU for one core/MF module) or can I connect them parallel in the 19" case and take the power again from a distribution point within the controller case?

THX and greets

Roger

[smashtv]

I have a few external powersupplies for external LACIE FireWire Harddisks.

These are usually switching type power supplies, and that is a bad thing for MIDIbox use.

See this thread for a past discussion about switching vs. linear power supplies.

Best!

SmashTV

[Screaming_Rabbit]

Thanks for the input Smash.

Is there a way for a electronics beginner like me to find out about it's a switching type or regulated?

I didn't open the plastic cases yet. Just this much:

It has the sice of a Laptop charger / powersupply and the label has got following printing: 5V  2.0A 10W (between the Voltage and the Amps there is a sign with a line above a second broken (dashed) line).

AC Input is 100-240V / 1.0A

Does the explained sign tell something about the type? If not can anybody tell me what I have to look for, when I open the case?

Greets, Roger

[Screaming_Rabbit]

Ooops... bad news.

Found it on the web:

http://www.gpcpower.com/details.cfm?productid=13

Thanks for your answers anyway

Roger

[Steven_C]

Did you give up because of the amount of work or caused by problems?

Both. But I may pick it up again early next year...

[Screaming_Rabbit]

Is a switching PSU only a problem on the 12V side for the motorfaders or as well on the 5V side? I mean, does the jitter-problem come from the AIN or from the fader motors?

Greets, Roger