Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 08-02-2014, 13:03   #16
Registered User
 
nimblemotors's Avatar

Join Date: Apr 2011
Location: Sacramento, California
Boat: Solar 40ft Cat :)
Posts: 1,557
Re: How exact do electronics need 12 volts?

Quote:
Originally Posted by MarkJ View Post
Hi,

I bought a non-marine computer modem with a 120/220 volt power plug that converts it to 12 volts 1.67 amps. The actual modem input says 12 volts 1.66 amps.

I want to cut the power plug off and connect it into my 12 volt system which goes up to 14.4 volts day time.

Should the extra 2 volts be OK? Or will it blow the bloody thing to Kingdom Come?
There are usually two kinds of AC adapters, a simple transformer or a true regulated power supply. If you have the simple transformer one, the modem probably has its own regulation, and you'll be ok to connect directly to your 12v house power. If its a regulated 12v adapter, the modem might depend on that and have cheaper electronics itself, and then you need a dc-dc converter to clean up the power, or it might blow-up, or worse, work fine for weeks or months, and then fail.
__________________

__________________
JackB
MiniMPPT Solar Controller
nimblemotors is offline   Reply With Quote
Old 08-02-2014, 13:22   #17
Long Range Cruiser
 
MarkJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2007
Location: Australian living on "Sea Life" currently in England.
Boat: Beneteau 393 "Sea Life"
Posts: 12,828
Images: 25
Re: How exact do electronics need 12 volts?

Quote:
Originally Posted by nimblemotors View Post
If its a regulated 12v adapter, the modem might depend on that and have cheaper electronics itself, and then you need a dc-dc converter to clean up the power, or it might blow-up, or worse, work fine for weeks or months, and then fail.
The adapter data sheet at PSAA20R-120
http://www.phihong.com/assets/pdf/PSAA20R.pdf

Says Line Regulation 5% and Load Regulation 5% so that means its Regulated?

Thank for your help
__________________

__________________
Notes on a Circumnavigation.
OurLifeAtSea.com

Somalia Pirates and our Convoy
MarkJ is offline   Reply With Quote
Old 08-02-2014, 13:31   #18
Registered User
 
nimblemotors's Avatar

Join Date: Apr 2011
Location: Sacramento, California
Boat: Solar 40ft Cat :)
Posts: 1,557
Re: How exact do electronics need 12 volts?

Quote:
Originally Posted by MarkJ View Post
The adapter data sheet at PSAA20R-120
http://www.phihong.com/assets/pdf/PSAA20R.pdf

Says Line Regulation 5% and Load Regulation 5% so that means its Regulated?

Thank for your help
Yep, that is switching regulated power supply, and not just a transformer, so chances are you could blow up the modem with the 12v house power.
__________________
JackB
MiniMPPT Solar Controller
nimblemotors is offline   Reply With Quote
Old 08-02-2014, 13:41   #19
Long Range Cruiser
 
MarkJ's Avatar

Cruisers Forum Supporter

Join Date: Dec 2007
Location: Australian living on "Sea Life" currently in England.
Boat: Beneteau 393 "Sea Life"
Posts: 12,828
Images: 25
Re: How exact do electronics need 12 volts?

Quote:
Originally Posted by nimblemotors View Post
Yep, that is switching regulated power supply, and not just a transformer, so chances are you could blow up the modem with the 12v house power.
Thanks.

OK off to the shop Monday.
No Ebay, or Amazon in the Caribbean!


Mark
__________________
Notes on a Circumnavigation.
OurLifeAtSea.com

Somalia Pirates and our Convoy
MarkJ is offline   Reply With Quote
Old 08-02-2014, 13:57   #20
Registered User
 
bill good's Avatar

Join Date: Oct 2006
Location: Brisbane Australia
Boat: sold
Posts: 721
Re: How exact do electronics need 12 volts?

G'Day Mark, It will work BUT ensure you get the + right way as it is not always + to tip.

Regards
__________________
bill good is offline   Reply With Quote
Old 08-02-2014, 15:21   #21
Registered User
 
sparrowhawk1's Avatar

Join Date: Jan 2014
Location: Miami Beach Fl
Boat: Colombia Cc 11.8
Posts: 1,252
Quote:
Originally Posted by conachair View Post

Good idea
These are the ones I've used..
http://www.amazon.com/Converter-3-5-...ref=pd_sim_e_6
Reliable so far, buy few, very handy.
Thanks for the link. It's worth it to have them always at the set voltage, even if my batteries are low my anchor light will be bright
__________________
sparrowhawk1 is offline   Reply With Quote
Old 08-02-2014, 16:01   #22
Registered User
 
sparrowhawk1's Avatar

Join Date: Jan 2014
Location: Miami Beach Fl
Boat: Colombia Cc 11.8
Posts: 1,252
Quote:
Originally Posted by MarkJ View Post

Thanks.

OK off to the shop Monday.
No Ebay, or Amazon in the Caribbean!

Mark
I thought Amazon shipped worldwide
__________________
sparrowhawk1 is offline   Reply With Quote
Old 08-02-2014, 16:51   #23
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: How exact do electronics need 12 volts?

Quote:
Originally Posted by MarkJ View Post

Should the extra 2 volts be OK? Or will it blow the bloody thing to Kingdom Come?
In most cases it will be fine, but you don't know till you try it.

It is worth measuring the voltage of the supplied brick often it is over 12v which gives me more confidence. A simple solution is add one, or even a couple of diodes in series.this is very easy to do when you wire up the plug. Each one of these takes of about 0.6 v so one takes the battery voltage from say 12.3-14.4v to 11.7-13.8v which is usually better.
Make sure it is disconected for an equalisation cycle.

Anything for automotive use is usually designed to run off 13.8v (even if it says 12v) so has a little more leeway.
__________________
noelex 77 is offline   Reply With Quote
Old 08-02-2014, 21:21   #24
Registered User

Join Date: Nov 2007
Location: Probably in an anchorage or a boatyard..
Boat: Ebbtide 33' steel cutter
Posts: 3,537
Re: How exact do electronics need 12 volts?

Quote:
Originally Posted by sparrowhawk1 View Post
I thought Amazon shipped worldwide
Like Gandhi said about democracy, overnight deliveries would be a good idea
Unfortunately what a next day delivery in much of the world actually ends up like is trying to guess which particular shack operating as an office your parcel might end up sitting on a shelf in and going to all of these every day for several weeks, also hoping you don't get stung for import tax because it's cloudy that day.
Next day deliveries are more an exercise in optimism than a system to transport goods.
__________________

__________________
conachair is offline   Reply With Quote
Reply

Tags
electronics

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:13.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.