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Ac to DC power converter recommendation

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10 replies to this topic

#1 KungFood

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Posted 26 January 2022 - 04:03 PM

I posted this in the equipment/mounts forum but got no traction, so I'll try here.

 

I recently got a Pegasus power box, and to my surprise found that my AC>DC power supply was providing 15+ volts, far too much. So much in fact that the power box refused to boot, giving me an over-voltage warning. So I tried two others that I had, both supplied less than 12v, one was 11.5, the other 11.3v. I ordered another, and dang it, 11.7 down to 11.5 with the dew heaters on. I've read that the EQ6 really really doesn't like to be undervolted, and that being in the 13v range is preferable. I don't however want to order 20 more inverters to find one good one. Can anyone recommend an AC to DC inverter, 12v+ 10amp, U.S. plug with the cigarette lighter socket? Really hoping to only buy one more and have it work. I run on wall power both at home and at the dark site, so looking for a plug in solution, not a battery.

 

Looking for recommendations from folks who have seen actual delivered voltage measured in some way.

 

A secondary question, how much undervolting is considered too much, is 11.5v too low? Am I splitting hairs?

 

P.s. inverter, converter, power supply? which is the correct term?


Edited by KungFood, 26 January 2022 - 04:05 PM.


#2 fuadramsey

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Posted 26 January 2022 - 04:14 PM

I use this one that costs only 20 bucks.

 

BINZET AC to DC 12V 10A 120W Power Supply Adapter Converter Regulator, 5.5mm x 2.1mm DC Plug, 12Volt 10Amp Wall Power Plug for DC12V 5050 5630 Flexible LED Strip Lights

 

https://www.amazon.c...e?ie=UTF8&psc=1



#3 bobzeq25

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Posted 26 January 2022 - 04:15 PM

I'm skeptical about the reports that the EQ6-R doesn't like 12.0 V.  I wonder if that's measured at the source, and there's power drop due to marginal wiring.

 

So, if you want reliable power that the Pegasus will be happy with, consider a computer power supply.   5V available, as well as 12, that may be convenient.

 

I use a 12V lead acid battery charged by a solar cell.  Starts the night at 13+volts, everything works fine right down to 12.0V, maybe a bit farther.

 

I have taken pains to be sure my wiring and connections is/are robust.  Old car racer.  Anderson Powerpoles to 12 gauge wires to Wago lever operated connectors to 16 gauge equipment wiring with factory assembled plugs.  I would not dream of using a cigarette lighter plug past the initial connection (if I had to plug it into a car).


Edited by bobzeq25, 26 January 2022 - 04:17 PM.


#4 Alex McConahay

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Posted 26 January 2022 - 04:15 PM

It is not unusual that a 12 volt power supply supplies 13.8 to 14 volts. (I mean, the standard 12 volt car battery is at 12.8-13.?)

 

Would that set off warnings on your Pegasus?

 

Alex



#5 pedxing

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Posted 26 January 2022 - 04:26 PM

You might consider a DC-DC buck/boost converter on your output so you can set the output voltage to whatever you want it to be.

 

I do this with my batteries. It's not as big of a deal with LiFePO, but when I was on Lead-Acid, this really helped with the varying output voltage. Same would be the case with a AC to DC power supply.


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#6 Midnight Dan

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Posted 26 January 2022 - 04:43 PM

I use a Powerwerx supply for my observatory.  I've tried cheap supplies available from Amazon, but they tend to have a lot of high frequency noise.  The Powerwerx supplies delivery solid, reliable, clean power, but they're not cheap.

 

Fixed 14.1V/30A supply: https://powerwerx.co...upply-powerpole

Variable V/30A supply: https://powerwerx.co...l-meters-30ampĀ 

 

The connections are the rear are simple screw/banana type terminals, but it's easy enough to connect a cigarette lighter outlet to those if that's what you prefer.

 

-Dan



#7 TelescopeGreg

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Posted 26 January 2022 - 04:47 PM

What Pedxing said.  If you already have a supply with sufficient power capacity (just the wrong voltage), the best path might be to get a "buck/boost module" to convert the whatever-input voltage to a consistent 13.8v (or whatever) output.  There are many available, with a range of power capacities.


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#8 bobzeq25

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Posted 26 January 2022 - 05:04 PM

You might consider a DC-DC buck/boost converter on your output so you can set the output voltage to whatever you want it to be.

 

I do this with my batteries. It's not as big of a deal with LiFePO, but when I was on Lead-Acid, this really helped with the varying output voltage. Same would be the case with a AC to DC power supply.

 Which one do you use?  Current capacity can be an issue.  Noisy output can be an issue.



#9 starrycanuck

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Posted 26 January 2022 - 05:22 PM

If you are wall powering, have you considered the Pegasus AC supply that made for the PowerBoxes (with different DC cords based on the particular Pegasus box)?

 

I have the Powerbox Advanced and power it via the Pegasus AC supply; it, in turn, powers an HEQ5 Pro, Asiair Pro, ASI120 mini, and a couple dew heaters (my Z7II runs off its own battery for now).



#10 pedxing

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Posted 26 January 2022 - 05:28 PM

Which one do you use?  Current capacity can be an issue.  Noisy output can be an issue.

I use a DROK 15A step-up step-down converter (just looked on Amazon, not currently in stock), there are many others.

 

You have to make sure you have enough current capacity for sure.

 

I looked at the output on an oscilloscope, looked very clean at the (admittedly low) frequencies I looked at, I also put a big RF choke on the output just to be sure about the higher frequencies.


Edited by pedxing, 26 January 2022 - 05:29 PM.

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#11 KungFood

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Posted 27 January 2022 - 05:47 PM

Thanks all for the recommendations. I've ordered a new power supply and a buck thingy, we'll see how it goes!


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