12v AC into MFC-101

The MFC comes with its own DC power supply. You supply the MIDI cable. If you want phantom power, buy a 7-pin MIDI cable. If not, use a standard 5-pin MIDI cable and plug the (supplied) power supply directly in to the MFC101.
 
A POD power supply will run the MFC-101

There are enough of those at garage sales and in spare parts bins around here.
 
jnapo said:
Please educate someone new here. Why is this even a question does the controller come with its own power supply?
Click to expand...
My "educated guess" is that aircadet is from Australia, and since IM doesn't have the MFC price yet, it got the MFC from the Yahoo store... but he needs the EU power supply (240V 50Hz) and may be a plug adaptor.
I think the question is interesting, it let me know the MFC is using a switching converter without opening the unit ;) and it can be battery powered for a reasonable amount of time without looking all the other forums (thank you Robboman) :)

jmpatrick said:
The MFC comes with its own DC power supply
Click to expand...
For the sake of clarity the MFC has an AC power supply.
 
terry64 said:
jnapo said:
Please educate someone new here. Why is this even a question does the controller come with its own power supply?
Click to expand...
My "educated guess" is that aircadet is from Australia, and since IM doesn't have the MFC price yet, it got the MFC from the Yahoo store... but he needs the EU power supply (240V 50Hz) and may be a plug adaptor.
I think the question is interesting, it let me know the MFC is using a switching converter without opening the unit ;) and it can be battery powered for a reasonable amount of time without looking all the other forums (thank you Robboman) :)

jmpatrick said:
The MFC comes with its own DC power supply
Click to expand...
For the sake of clarity the MFC has an AC power supply.
Click to expand...

My bad. You are absolutely correct.
 
terry64 said:
jnapo said:
Please educate someone new here. Why is this even a question does the controller come with its own power supply?
Click to expand...
My "educated guess" is that aircadet is from Australia, and since IM doesn't have the MFC price yet, it got the MFC from the Yahoo store... but he needs the EU power supply (240V 50Hz) and may be a plug adaptor.
I think the question is interesting, it let me know the MFC is using a switching converter without opening the unit ;) and it can be battery powered for a reasonable amount of time without looking all the other forums (thank you Robboman) :)

jmpatrick said:
The MFC comes with its own DC power supply
Click to expand...
For the sake of clarity the MFC has an AC power supply.
Click to expand...

Actually I live in the UK & my MFC came with a mainland European PSU because, I think, not enough UK ones were sent with them. I've been using a 12v one with my All Access for 2 years without problem & wanted an official line if the MFC would take it. Any way I since found a 9v AC 500ma in my drawer so I'm using that until the correct one comes. I got stacks of the 12v Ac power supply from work so hoped I hoped I could use them as spares, anyway job done.
Cheers, Paul
 
Out of interest I measured the output voltage of the Fractal 9VAC 1000mA (UK) adapter that came with my MFC. It was reading about 11.3VAC output. I also tested another 9V AC/AC 1000mA adapter I have, and that one was reading about 12.2 VAC output. Does this mean they all generally put out way more tham 9VAC? I have been using the Fractal one for ages, with no signs of trouble. Also I have used a generic 9VDC adapter (that actually does put out 9VDC) with no issues at all. I am no electrical expert, far from it, but It'd be nice to know what's considered 'safe' for use with the MFC.
 
craiguitar said:
Out of interest I measured the output voltage of the Fractal 9VAC 1000mA (UK) adapter that came with my MFC. It was reading about 11.3VAC output. I also tested another 9V AC/AC 1000mA adapter I have, and that one was reading about 12.2 VAC output. Does this mean they all generally put out way more tham 9VAC?
Click to expand...
Are you sure you were measuring AC voltage and not DC voltage? (Though if that were the case, I would expect the meter to show 0, ~5.7, or an error.)
 
craiguitar said:
Out of interest I measured the output voltage of the Fractal 9VAC 1000mA (UK) adapter that came with my MFC. It was reading about 11.3VAC output. I also tested another 9V AC/AC 1000mA adapter I have, and that one was reading about 12.2 VAC output. Does this mean they all generally put out way more tham 9VAC? I have been using the Fractal one for ages, with no signs of trouble. Also I have used a generic 9VDC adapter (that actually does put out 9VDC) with no issues at all. I am no electrical expert, far from it, but It'd be nice to know what's considered 'safe' for use with the MFC.
Click to expand...

You are probably measuring peak AC voltages while real things are spec'ed in RMS (root mean square) voltages because that's more useful as it directly relates to power even with non sine wave signals. A good multimeter will measure "true-RMS" and optionally peak voltages. Cheaper ones only measure peak.

You measure 9 volts on your DC pack because there is only one voltage, peak and RMS are the same at DC, and even a cheap meter measures this right.

Get yourself a Fluke... http://www.fluke.com/Fluke/usen/Digital-Multimeters/Fluke-170.htm?PID=56027

Darryl
 
craiguitar said:
Out of interest I measured the output voltage of the Fractal 9VAC 1000mA (UK) adapter that came with my MFC. It was reading about 11.3VAC output. I also tested another 9V AC/AC 1000mA adapter I have, and that one was reading about 12.2 VAC output. Does this mean they all generally put out way more tham 9VAC?
Click to expand...
"Wall wart" power supplies usually have pretty high impedence (as power supplies go). In other words, they eat up some of their own power, eating more of it as the load increases.

With no load to drive, they put out more voltage than what they're rated for. As you start to draw current, the output voltage drops. When you reach the rated output current, the output voltage should (but doesn't always) drop to the rated voltage. Draw more power still, and the output voltage drops below the rated voltage.
 
Darryl Ramm said:
You are probably measuring peak AC voltages while real things are spec'ed in RMS (root mean square) voltages because that's more useful as it directly relates to power even with non sine wave signals. A good multimeter will measure "true-RMS" and optionally peak voltages. Cheaper ones only measure peak.

You measure 9 volts on your DC pack because there is only one voltage, peak and RMS are the same at DC, and even a cheap meter measures this right.

Get yourself a Fluke... Multimeter | Fluke 170 Series Digital Multimeters - Fluke 179, 177, 175 multimeters

Darryl
Click to expand...

Mine is a Fluke.
 
Rex said:
"Wall wart" power supplies usually have pretty high impedence (as power supplies go). In other words, they eat up some of their own power, eating more of it as the load increases.

With no load to drive, they put out more voltage than what they're rated for. As you start to draw current, the output voltage drops. When you reach the rated output current, the output voltage should (but doesn't always) drop to the rated voltage. Draw more power still, and the output voltage drops below the rated voltage.
Click to expand...

Thanks. I thought it might be something like this. Makes sense.
 
2nd Rex's comment on AC 'wall wart' supplies.


BLUF (Bottom Line Up Front): I would NOT reccomend that you put a 12V AC rated power supply into the MFC unless Fractal says this is acceptable.


Details: Small AC 'Wall Wart' power supplies SAG alot under load (similar to tube DC supplies that are modeled).. When measuring an AC small size transformer, it should be done under load (as specified on the wall wart).. Measuring the open circuit (no load) will give a higher reading (Peak or RMS) and this is why users are reading 12VAC from the Fractal AC supply. Larger transformers (like in a big solid state power amplifier) do not SAG much at all (lots of iron and big thick windings). When the AC wall wart is under load, it would be (not measured) near 9V. A '12VAC' rated AC wall wart may actually put out a much higher peak voltage (the Fractal MFC one is ~12v as measured under no-load).

Note also that Cliff's comment is for a DC (battery) supply for the 12V (DC) acceptability (I'm not speaking for Cliff/Fractal). 12V AC is a different animal. 12V AC is typically the RMS (the effective DC equivalent voltage for the same heating/power into a resistive load), and the peak voltage would be at least 1.414x the AC RMS value (17V peak = 1.414 * 12 VDC). Normal 'RMS' reading Volt/Ohm Meters assume that the signal is a SINE wave and apply the 1.414 correction to the measured peak value, other 'True RMS' VOMs evaluate the signal waveform to give corrected RMS value. The 17V from a 12VAC wall wart exceeds the 12VAC intial startup voltage from the Fractal MFC supply, so this would exceed any presently stated ability. Another issue is that the AC signal is both positive and negative (that is OK for the MFC as it is an AC powered device, not OK for regular stomp boxes..).

As for the MFC power supply, it is a switching power supply (internal to the MFC) and like normal desktop PC supplies it tends to make the load a constant power as a function of input voltage. The MFC is specified at 10 Watts (manual), so 9VAC or 12VAC it will still generally be about 10 Watts.

SIDE NOTE: How does a 'universal DC power supply work'?
A common desktop PC or many laptop power 'brick' will be rated for operation from 90VAC through 240VAC for 'universal' application. These power supplies work by doing 3 things in series.

1. Convert the input AC voltage to an internal DC supply. 90VAC * 1.4 = 127VDC and 240VAC *1.4 = 340VDC. This output will vary anywhere within this range (but that is ok).

2. Convert the high voltage DC into useful low voltage output(s). A single (or multiple parallel) switching converters 'switch' this high voltage DC into a small sized transformer (or other simpler single inductor) to charge a low voltage filter capacitor (electrolytic) at the near output DC level needed for the load. This switching is done at very high frequencies (200kHz to 1MHz) and this allows the transformer to be very small and light (vs 60Hz ones in a tube power amplfier).

3. Regulate this output voltage(s) to the specified required DC voltage. The internal regulator measures the output DC voltage and adjusts the switching 'duty cycle or charge time' to maintain the DC output voltage.

Key to these systems is knowing the range of load variation (output) and line changes (90-240VAC). These types of power supplies are very efficient (80 to 98% efficient) so don't put off alot of waste heat. Normal AC wall warts (AC or DC output) typically get warm as they normally are 60 Hz small format transformers (poor efficiency)..

End diatribe....
 
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