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Dieser Beitrag wurde bereits 1 mal editiert, zuletzt von »Gus« (17. März 2020, 23:35)
Hi!
According to the user manual for the aquaero 6 XT the power supply voltage is 12V DC plusminus 5% (and 5V DC plusminus 5%). Both voltages are supplied to the controller using a 4 pin female Molex plug.
Most users of this device probably just plug it to the computer PSU - but I'm not into computers. I don't even have one. I will be using the aquaero to control four fans in my homebuilt heating system on my sailboat. The boat electrical system is 24V DC so I intend to use a DC/DC converter to reduce the voltage from 24V to 12V (and another DC/DC converter for the 5V) before feeding it to the controller. However, many converters for marine use will provide between 13,2V and 14,2V (output voltage).
Since 12V+5% is 12,6V I will have an excess voltage of 0,6V to 1,6V.
Question 1: Will this damage the controller?
Question 2: If yes, is there a smart way to reduce the voltage from 13,2V-14,2V to 12V?
Any help would be highly appreciated!
Dieser Beitrag wurde bereits 1 mal editiert, zuletzt von »caronen« (18. März 2020, 13:58)
Thanx Caronen for a most informative reply!
Conclusion 1:I will stabilise!
I intend to use 8 fans: be quiet! SILENT WINGS 3 PWM (140 mm, 1000 rpm, 59,5 CFM)
According to their website the Current consumption is 0,06A and the Safety current - whatever that is? - is 0,3 A. On the fan it says 0,3A.
8 x 0,3 A = 2,4 A
If I decide in the future to change one or two of the fans to the high speed version (consumption 0,5 A) I will still be within 3 A.
Zitat
Unfortunately the 24 V source is not very stable. When the service battery bank is fully charged the voltage is above 25V. And when the battery charger runs the voltage is sometimes above 28V. However, I just found out that I allready have a few DC/DC converters installed in the boat. One is a Mascot Type 9460 24/12V. I measured the output voltage to 13,15V.
Conclusion 2: I will put a LT1083-12 (with one 10μF tantalum capacitor on each side) between the Mascot DC/DC converter and the Aquaero.
Zitat
Question 3: Where do I buy the LT1083? There seems to be several different models. What about this?:
https://www.ebay.com/itm/Ultra-Low-Noise…uUAAOSwtnpXlJSl
Zitat
Question 4: What about cooling? How do I achieve proper cooling?
Zitat
Question 5: Why are there two different ground pins in the 4 pin Molex plug? I understand that one is for the 12V and one for the 5V - but is it ok to connect them to the same ground? If the Traco and the Mascot are connected to the same ground on the input side, then there should not be any difference in ground level on the output side, right?
Zitat
I'd love to measure the temperature at a number of different locations in the boat, but the temp sensing cables supplied with the Aquaero are only 70 cm long.
Question 6: Is there any way to lengthen these cables without getting bad readings? In the manual there is a list of compatible sensors, so I guess any modification would not qualify. But this isn't magic right, it's electronics, and either way you seem to be a wizard, so perhaps there is a way?
The distance from the Aquaero to the fans vary between 7,5 and 9 meters. I intend to use shielded copper cable (Veriflex CY LSZH 4 x 0,75mm2) which would give a voltage drop of only 0,129V.
Aint that smart?
Zitat
Well, first of all I’ve looked to the Mascot 9460 datasheet and it is
actually a stabilized converter with 13,2 V output voltage. So, this is
kinda good news. Then, the datasheet says “output voltage internally
adjustable 9,0-14,5 V” - usually there is some sort of a knob to be
turned with a screwdriver, but I do not see any on the photo.
Unfortunately the manual says nothing about it being user-adjustable. In
fact, the manual barely says anything useful, but You could perhaps
contact Mascot – this would solve all your problems…
Of course, setting the Mascot to 12 V is a solution only if You don’t need it to provide 13,2 V something else.
Zitat
Well, first of all I’ve looked to the Mascot 9460 datasheet and it is
actually a stabilized converter with 13,2 V output voltage. So, this is
kinda good news. Then, the datasheet says “output voltage internally
adjustable 9,0-14,5 V” - usually there is some sort of a knob to be
turned with a screwdriver, but I do not see any on the photo.
Unfortunately the manual says nothing about it being user-adjustable. In
fact, the manual barely says anything useful, but You could perhaps
contact Mascot – this would solve all your problems…
Of course, setting the Mascot to 12 V is a solution only if You don’t need it to provide 13,2 V something else.
Please stand by for Mascot investigation
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This thread is rapidly deviating from my initial Aquaero related topic, namely if the Auaero 6XT would handle my overvoltage powersource, and the discussion may not be of interest to anyone in this forum but me? Is it advisable to continue in some other format, e. g. email?
Ok. May I ask you to tell me how to post a picture here. I'm asked to type the picture URL. Does the picture have to be published on internet to get an URL?Zitat
As You wish, in my opinion no need, it can be useful for more than one person.
Zitat
Please stand by for Mascot investigation
Based on your comment above, and before connecting the Aquaero I figured it would be a wise thing to measure the voltage between input and output ground on the Mascot and the Traco. It turned out that there was no difference between input and output ground on the Mascot. On the Traco however the output ground was 0,54V above input ground. Needless to say I didn't connect the Aquaero.Zitat
As always there is a long story behind. Basically, both wires are
supposed to be same potential (ground) and there are two of them in
order to increase current carrying capacity. Sometimes these are
internally also connected on a device.
However, if you use a LT1083 module with rectifier diode bridge
connected directly to the 24 V source, You have to be careful as the
output ground sits 0,7 V above input ground. Traco is an isolated
converter so it will work but You must connect output grounds from
LT1083 and Traco and avoid any connection to the mains (24 V) ground.
And still, it is not an elegant solution, I would rather get rid of this rectifier bridge all along.
Pls clarify. What do you mean? Is there any way I can use the Traco and the Mascot to power the Aquaero?Zitat
Traco is an isolated
converter so it will work
Ok. May I ask you to tell me how to post a picture here. I'm asked to type the picture URL. Does the picture have to be published on internet to get an URL?
Zitat
I opened the Mascot converter and found an adjustable knob. I managed to set the output voltage to 11,99V. So far so good.
Zitat
Based on your comment above, and before connecting the Aquaero I figured it would be a wise thing to measure the voltage between input and output ground on the Mascot and the Traco. It turned out that there was no difference between input and output ground on the Mascot. On the Traco however the output ground was 0,54V above input ground. Needless to say I didn't connect the Aquaero.
Pls clarify. What do you mean? Is there any way I can use the Traco and the Mascot to power the Aquaero?Zitat
Traco is an isolated
converter so it will work
Dieser Beitrag wurde bereits 10 mal editiert, zuletzt von »caronen« (29. März 2020, 19:30)
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