Too expensive and not ok for 74A.
A MeanWell RS-15-3.3 with the stanby mode is less expensive.
http://www.mouser.fr/ProductDetail/...=/ha2pyFadui/CsClz4Ycutd82McfmGoDBRukcADmJFM=
The tolerance of the Vout is a tad low... 2.9V
You should use the RS-15-5 instead.
http://www.mouser.fr/ProductDetail/Mean-Well/RS-15-5/?qs=sGAEpiMZZMuSK2mCDyT9ctxxenF4WJtP
So how does the timing work? The small power supply comes on quickly enough to send the large power supply to standby mode before it can draw the surge current? I understand that once it is plugged in you would use a smaller switch to control the small supply to toggle the standby input, but what about initial connection? I suppose they've thought of that, I just can't find where it's listed.
Mistake ! (again😀) the tolerance is 3% (3.2V) both RS15-3.3 and RS15-5 are quite good for your application !
The small power supply inrush current is 65A... but they don't specify the time duration of this peak, as Hypex.
I was not aware of that huge power peaks with SMPS PSUs, you can use ballast resistors to limit the inrush current with a linear PSU.
IMHO you should not use resistors with a switching PSU and i was expecting that these PSUs were equipped with a internal soft start.
So... the Meanwell RS15-3.3 and the Hypex SMPS1200 are permanentely connected to the AC... and you put a small (or big) switch on the output of the Meanwell RS15-3.3 to feed (or not) the standby pin of the Hypex SMPS1200 in order to switch it on of off.
"Applying an external DC voltage to the Amp Standby pin will put the amplifier in standby."
PS: if the swich is closed at a the cold start... i don't know what may occur 😕
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I think I'll just go ahead and wire one up hard to the 20A switch I have and measure the real surge current. If the spike above 20A is too brief for my ammeter to measure, it probably won't cause any harm to the switch. What would the failure mode be, anyway? I'm guessing that it would weld the contacts, not cause some sort of catastrophic failure that would send pieces flying and energize the case.
On the one hand I'm surprised that the manufacturers don't spell this out better, but on the other hand it might be the sort of thing that's so basic to the electrical people that they don't bother mentioning it. I'm coming at it from the mechanical side, and I know that there are all kinds of things that don't get listed in a mechanical description because they just don't matter.
On the one hand I'm surprised that the manufacturers don't spell this out better, but on the other hand it might be the sort of thing that's so basic to the electrical people that they don't bother mentioning it. I'm coming at it from the mechanical side, and I know that there are all kinds of things that don't get listed in a mechanical description because they just don't matter.
There's this one, but the rating looks like I would need two of them. It would be great if I could find a way to turn these on safely without placing another $100 international order.
https://www.hypexshop.com/DetailServlet?detailID=1474
https://www.hypexshop.com/DetailServlet?detailID=1474
Manufacturer informations are quite good, the SMPS input rush current is enormous, your 20A switch will work but with a reduced life expectancy.
There is a small 10A switch on the back on the computers PSUs, but it is not designed for a daily use at all. (life expectancy seem very very short)
This soft start is designed for hypex toroidal transformers, don't use it with an SMPS, it should harm or destroy it.
The big advantage of linear PSU with that kind of circuit is that you can charge the capacitor very slowly and extend drastically their durability.
High quality caps can last forever when they are not brutalized.
"Transformer inrush current limiter"
You can't use it with a switched mode PSU.
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All you need is cheap low voltage power supply, like I said, mobile phone charger at 5V is perfect and a NC (normally closed) switch, current rating irrelevant for this application, led illuminated antivandal switches are nice.
Kind regards
Marko
You are right but the problem is exactly the same, his answer was about the synchronisation of the two PSU.
You must connect the standby trigger PSU before the SMPS PSU... apparentely.
I couldn't immagine a 2000$ high end 8 channels digital amp in a big high quality massive aluminium enclosure with a small cappy wallplug PSU plugged in it 24h/365D to keep it off... irresisitible
What think about a cheap wallplug PSU for an 24h/365D application ?
If it fails your amp goes on... without your permission.
If it goes under 3.3V it don't goes on.
If it exceed 5.5V it overheat the SMPS internal components.
You are right but the problem is exactly the same, his answer was about the synchronisation of the two PSU.
You must connect the standby trigger PSU before the SMPS PSU... apparentely.
I couldn't immagine a 2000$ high end 8 channels digital amp in a big high quality massive aluminium enclosure with a small cappy wallplug PSU plugged in it 24h/365D to keep it off... irresisitible
What think about a cheap wallplug PSU for an 24h/365D application ?
If it fails your amp goes on... without your permission.
If it goes under 3.3V it don't goes on.
If it exceed 5.5V it overheat the SMPS internal components.
Sync is easy, I am using one mobile charger for two hypex smps, just split the wires, AC side of wallplug goes via switch.
I am using this solution for two years on a daily basis, so you can guess my opinion.
Regards
Marko
Use an AC/DC power converter to pull up the standby trigger. They cost about $15, and can be mounted internally inside the cabinet. They're avalable as through hole and SMD components as well as standalone components that can be mounted internally in the enclosure.
RAC04-05SC/W Recom Power | Power Supplies - External/Internal (Off-Board) | DigiKey
Johan-Kr
RAC04-05SC/W Recom Power | Power Supplies - External/Internal (Off-Board) | DigiKey
An externally hosted image should be here but it was not working when we last tested it.
Johan-Kr
Yes, but the question was "how can i wire the two PSUs inside the cabinet and what occur if these two PSU start a the same time?"
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mkusan, you should be very sympathetic if you try to plug your mobile charger and your hypex SMPS on the same AC power distributor and plug this distributor on the AC to see what occur when the two PSUs are connected simultaneously !
In all likelihood Hypex has a short delay in the SMPS1200 before the full surge current, giving a small parallel connected supply to come up and put it into standby, but it would need to be measured for confirmation because it's not on any spec sheet that I see.
This thread is getting weirder and weirder, and I am not sure if it is a language barrier or you are pulling my leg. This is how it should be connected. I was lazy to look at the manual for real pinout but it should be obvious what to connect where, amp will be off when you connect IEC receptable to the mains. If you have trouble using cheap mobile charger for the purpose, use 4,5V battery, I am sure it will last a long time in that position.
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Joe, congratulations on your purchase, you bought state of the art PSU.
Now stop over thinking this and do as Hypex engineers designed the PSU to be used and started.
There is a NTC resistor which protects against inrush over-current. On VSSA threads some users even replaced it with a wire as a modding exercise, along with caps change.
Kind regards
Marko
Where does it say how they designed it to be started? I'm sorry, I seriously can't find a schematic on their site that says "wire it like this". I'm sifting through the forums and researching as I can, but I feel like I'm still in the dark here.
Further research: it appears that TV5 and TV8 rated switches are intended to survive the inrush current that we might be dealing with here, although they all seem to be rocker style switches with rectangular cutouts.
http://www.mouser.com/ds/2/295/JW-31100.pdf
http://www.mouser.com/ds/2/295/JW-31100.pdf
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