Walrus
Well-known member
These work perfectly.....
https://www.mouser.co.uk/ProductDetail/XP-Power/ECE05US48?qs=w/v1CP2dgqppNtKJJpT2uQ==
https://www.mouser.co.uk/ProductDetail/XP-Power/ECE05US48?qs=w/v1CP2dgqppNtKJJpT2uQ==
The constant current source has a defined current while the voltage across it is not defined and depends on the load. A real current source has a limit of that "floating" voltage and in this case it is 48V. This also means that the output voltage at the CC source will be 48V for all loads less than 350mA in this case. This is not a normal work area for CC source but an end point, for which this SMPS is not actually designed. And very often that voltage is not accurate and can fluctuate.
Note that this is not isolated. So you cannot "stack" these. But for 48V, it might be ok. They're so small I would be weary and study the noise performance intently before committing. But they are so small it is very attractive.These work perfectly.....
ECE05US48
CC because they don't put as much effort into regulating the voltage
You select a number of series and parallel LEDs to make some voltage, like say 40V
Note that this is not isolated.
That's not what I have observed. The output voltage is in fact a steady 48V. So below the rated current, voltage is regulated. It's only when you reach the rated current that current becomes regulated.The voltage is not regulated at all, the current is regulated.
They must. There are no individual LEDs that use 350mA. Power LEDs now are multiple individual LEDs on one "chip" that are wired in series and parallel. Older models did not divide current perfectly and you could sometimes see variations in brightness of individual LEDs. Newer "chip" LEDs are actually pretty well matched even at low currents.I doubt you would use parallel strings, because you have no way to guarantee that the current divides evenly between the strings.
I have used 5 different CC MeanWell SMPS and 4 different models. I can't recall testing each one like I did the APC-16-350, but my recollection is that they all worked the same way.It seems to me that if a particular constant current supply works out OK when running at the limit voltage, it is a matter of luck, since the operation is not specified at all in that region. A different model may behave differently, or different revisions of the same model may behave differently since the manufacturer makes no claims at all about behavior at the limit. I would not want to press my luck that way when you can just by supplies that are designed to regulate the output voltage.
True. Good point.Of course it is isolated, it is AC input.
Right at the top of the datasheet: "Isolation • 4000 VAC Input to Output"
Hi Kevin,..I have built a few stereo mic amps now with these. Just add a common mode choke and
capacitance multiplyer and the jobs a good'n!
That's not what I have observed. The output voltage is in fact a steady 48V. So below the rated current, voltage is regulated. It's only when you reach the rated current that current becomes regulated.
Of course it is isolated, it is AC input.
Right at the top of the datasheet: "Isolation • 4000 VAC Input to Output"
Hi Richard, yes it will work fine for a 3 channel mic pre as the absolute maximum current through available through two 6.8 kOhm phantom resistors is only 14mA, so if all three pres had shorted inputs the max will be 42mA.Hi Kevin,
I need to build a 48 volt supply for a three channel mic pre. Would this device provide enough current for that? Would you have an example of the circuit using this with a capacitance multiplyer and common mode choke, or know where to point me to one?
- Richard
Hi Kevin,Hi Richard, yes it will work fine for a 3 channel mic pre as the absolute maximum current through available through two 6.8 kOhm phantom resistors is only 14mA, so if all three pres had shorted inputs the max will be 42mA.
The circuit I used for filtering is at work, I’ll try to remember to look it up Monday.
Here is the circuit I used. The choke was from RS Components order number 863-3807. It may not be the best one, but it does reduce the switchiong noiuse considerably.Hi Kevin,
That's very kind of you - much obliged,
Richard
The datasheet says: max. output current is between 21mA and 25mA. With your 42mA you are out of specs.Hi Richard, yes it will work fine for a 3 channel mic pre as the absolute maximum current through available through two 6.8 kOhm phantom resistors is only 14mA, so if all three pres had shorted inputs the max will be 42mA.
The circuit I used for filtering is at work, I’ll try to remember to look it up Monday
Hello I´ve looked for the 10 Watt model.Which data sheet are you looking at?
View attachment 99377
??? The datasheet is clear, 0.1A at 48V. It should be capable of powering at least 10 mics (or supporting 7 shorted connections).For a 3 channel mic pre these ranges aren´t so good, beecause the power isn´t enough.
I would very carefully test a new SMPS module under low load for sure. I would not be shocked if the noise floor changed and you got whistling in the audio range under light load. The datasheets are sparse on details like that but it does say the non-5V models have a max ripple of 1% which in this case would be 480mVpp which is quite high.I would just be a little concerned about how it behaves with a very light load, which would happen with only 1 mic connected. However, the datasheet says: "No minimum load required", so it should be a non-issue.
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