Circuit or device to smooth voltage drop
Norman Hirsch
I have a electronics box mounted to my hardtop on my Grady White. I
have Raytheon Loran and ChartPlotter and these plus my AM/FM radio and
my night lights are all coming from the same 12V feed. It looks like
a decent sized wire, nevertheless I have two problems. First is that
there is noise on the radio. I think I can fix that by a noise
filter and separating the Raytheon equipment from the radio.
The problem I'm seeking help on is that when I turn on the night
lights, the Raytheon Chartplotter (Model 600) loses power.
Apparently there is a voltage drop enough to shut it off. Raytheon
advises that if the voltage drops below 11V, the unit will drop shut
off. If I put the unit back on with the lights on, the ChartPlotter
will stay on and work fine. The problem is I have to wait, and then
reset it to my position, etc.
I was wondering if anyone knows of a device or circuit diagram which I
can put together myself such as with a capacitor that would smooth the
voltage drop when I turn on the lights so the ChartPlotter won't go
out. I don't want to run another power line and I don't want to use
my other battery which is solely responsible for making sure the
engines will start if I've shut them down for awhile and used up the
power in the other battery.
---
Norman Hirsch Fax: 212-304-9759
NH&A BBS: 212-304-9759,,,,,,,3
577 Isham St. # 2-B CompuServe: 72115,661
New York, NY 10034 USA Internet: nhi...@nha.com
Phone: 212-304-9660 URL: http://www.nha.com
Howard V. Coley
nhi...@nha.com,NewsGroups writes:
>I was wondering if anyone knows of a device or circuit diagram which I
>can put together myself such as with a capacitor that would smooth the
>voltage drop when I turn on the lights
Go to your local highend stereo shop and get one of the big capacitors
that they use for the same think will the big power amps this will keep
the voltage up for a short period.
hope this is helpful,
Howard
Lawrence
In article <3417b984...@news.panix.com>, nhi...@nha.com says...
>
>I was wondering if anyone knows of a device or circuit diagram which I
>can put together myself such as with a capacitor that would smooth the
>out. I don't want to run another power line and I don't want to use
>my other battery which is solely responsible for making sure the
>engines will start if I've shut them down for awhile and used up the
>power in the other battery.
I'd nose around in the audio stuff. There are some filters with big
caps for the super hipowered audio folks designed to help with voltage
drops in the supply side on these multi hundred watt car amps that are
so popular these days. I'd think one of those might help you. A new
dedicated large gauge supply line from the battery would be cheaper
though. I doubt the voltage is dropping at the battery.
Russell A. McAllister
In article <5v3nt0$m...@drn.zippo.com>
Lawrence writes:
> >I was wondering if anyone knows of a device or circuit diagram which I
> >can put together myself such as with a capacitor that would smooth the
> >voltage drop when I turn on the lights so the ChartPlotter won't go
> >out. I don't want to run another power line and I don't want to use
> >my other battery which is solely responsible for making sure the
> >engines will start if I've shut them down for awhile and used up the
> >power in the other battery.
>Go to your local highend stereo shop and get one of the big capacitors.....
You shouldn't need capacitors if your wiring is ok. Perhaps there is a
bad
connection in the circuit. Go over all the crimped connectors and
terminals.
You may even see or feel overheated connections when the lights are on.
A voltmeter will tell you where the voltage is being lost. If all the
connections are ok, then the wire might be too small a guage for the
load.
Another possibility is that the battery is almost dead, or bad.
I rewired a boat this summer, and used #6 wires from the battery to
the
instrument panel, one for hot and one for ground. The hot wire has a
breaker
close to the battery. The #6 hot wire goes to the fuse block, and then
the
voltage then goes to switches, etc. The ground #6 wire goes to a
multi-screw
grounding block. Each circuit's ground returns to this block. I don't
have
any voltage drop problems.
You must have a terrific voltage drop to cause that unit to kick out.
Good luck.
Russ
rmci...@lsil.com
>I was wondering if anyone knows of a device or circuit diagram which I
>can put together myself such as with a capacitor that would smooth the
>voltage drop when I turn on the lights so the ChartPlotter won't go
>out. I don't want to run another power line and I don't want to use
>my other battery which is solely responsible for making sure the
>engines will start if I've shut them down for awhile and used up the
>power in the other battery.
A capacitor stores a charge, which can be used to absorb voltage peaks and
supply power during voltag lows. It works OK for low current power supplies
where the highs and lows are alternating at 60 (or 120) cycles per second.
When you turn on the lights, you have a different situation. The filaments of
the bulbs are cold, and thus represent a very low resistance load. The initial
inrush current to the lights can be very high, and last for a fairly long time.
As the current heats the filaments, the resistance goes up, and the current goes
down. This is why you can restart the chart plotter once the lights are on.\
I am afraid that a capacitor large enough to supply the initial filament heating
(current times time) would be VERY large.
If the need is relatively short (a few minutes) you might consider adding a
small battery right at the chartplotter. You can purchase small gel cell
batteries for not too much, and they would provide a few amp-hours of storage.
Connect the the house battery to the gel cell/chart plotter through a diode.
The diode drop will protect the gell cell (which wants a slightly lower charging
voltate) and will keep the gel cell from trying to power the entire boat. Make
sure that the diode is rated for the load of the chartplotter plus about 10% of
the battery amp-hour capacity.
Another option would be to buy/built a DC-DC converter. Buying one might be
difficult, as there are not many applications that want to take 12 volts and
make 12 volts. Building one would be an option only if you are reasonably adept
at constructing electronic circuits. A resonable switching supply is pretty
much a cookbook type design, the only trick being getting the necessary
inductors.
You might also want to consider rewireing the lights (I assume from your post
that you have more than one) so that you turn on each light individually,
instead of all of them at once. This will reduce the inrush current, and
perhaps solve the problem.
You could also change the lights to florescent, which wouldn't have the inrush
current problem (but could cause additional radio interference problems).
Rod McInnis
Bad_Child
In article <3417b984...@news.panix.com>, nhi...@nha.com wrote:
>I have a electronics box mounted to my hardtop on my Grady White. I
>have Raytheon Loran and ChartPlotter and these plus my AM/FM radio and
>my night lights are all coming from the same 12V feed. It looks like
>a decent sized wire, nevertheless I have two problems. First is that
>there is noise on the radio. I think I can fix that by a noise
>filter and separating the Raytheon equipment from the radio.
>
>The problem I'm seeking help on is that when I turn on the night
>lights, the Raytheon Chartplotter (Model 600) loses power.
>Apparently there is a voltage drop enough to shut it off. Raytheon
>advises that if the voltage drops below 11V, the unit will drop shut
>off. If I put the unit back on with the lights on, the ChartPlotter
>will stay on and work fine. The problem is I have to wait, and then
>reset it to my position, etc.
>
>can put together myself such as with a capacitor that would smooth the
>voltage drop when I turn on the lights so the ChartPlotter won't go
>out. I don't want to run another power line and I don't want to use
>my other battery which is solely responsible for making sure the
>engines will start if I've shut them down for awhile and used up the
>power in the other battery.
>Norman Hirsch Fax: 212-304-9759
>NH&A BBS: 212-304-9759,,,,,,,3
>577 Isham St. # 2-B CompuServe: 72115,661
>New York, NY 10034 USA Internet: nhi...@nha.com
>Phone: 212-304-9660 URL: http://www.nha.com
Unfortunately, to fix the problem permanently, you'll need to run a dedicated
6 ga wire from the battery to the lights. The battery cells will smooth out
voltage fluctuations, and probably keep your chart plotter on. An electrolytic
capacitor large enough to store 10A at 12v for 2 seconds would be about the
size of a wastebasket. A second battery in Parralell will probably work also.
Steve
Rob Scott
I too have a GW with hardtop and had the same problem. What I found out by
studying the manual is their should be two power feeds to the hardtop
wired directly back to the battery and on their own circuit breaker. One
is dedicated for your radio and the other for the spreader lights and
accessories. Both are 10GA circuits. When my dealer installed the hardtop
they took the cheap and easy way out and simply wired one of the circuits
to the helm station fuse block. Big time drop especially when you turn
those spreader lights on.
I yanked out the crap my dealer did and ran the two power feeds per the
hardtop wiring diagram in the manual. I then installed a Newmar power
filter on one circuit and used this for my VHF, AM/FM radio, and
GPS/fishfinder. The other circuit is used for the spreader lights and dome
light. Theoretically, you should dedicate one circuit solely for the VHF,
but there is no way you could run any electronics on the spreader light
circuit and three power feeds just would not fit up the pipes.
Since my AM/FM radio operates a power amp elsewhere on the boat, it and the
GPS/fishfinder are not significant power draws and do not interfere with my
VHF. The only problem I have encountered is the fishfinder ping does
couple into the AM band (a slight click) on the radio. Since I never
listen to AM I have not installed another filter between them.
I then complained to GW about what my dealer had done and received proper
compensation from them.
Don't bother trying to get one circuit to operate everything. You just
can't do it - trying to use capacitors, filters and/or DC-to-DC converters
is not the way. You need the two separate feeds right back to the battery
the way GW designed it...
I would call GW customer service at: (919) 752-2111, and ask for Jeff. I
am sure he would be happy to send you the wiring diagram.
Rob
Norman Hirsch <nhi...@nha.com> wrote in article
<3417b984...@news.panix.com>...
coo...@capital.net
Just to add "My 2 cents worth"
You can never have a supply line to large.
(Up to the equal physical size of the battery post or connection tab).
With over 30 years of "fixin electric stuff " you would be surprised
how many times I have found small gauge wires in series with large gauge
wires feeding equipment with a high current draw.
Don't neglect the actual battery terminals." Make em bright and shiny"
with a wire brush and don't forget to give the "Ring terminals" a little
brush also. If a post type battery use one of the post and cable
connection wire brush tools, they work well. If a bolt tightened "Split
clamp" type connection, make sure the bolt is in good shape and will
clamp around the post nice and tight yielding a good low resistance
mechanical connection. Come on guys use a wrench! Not Channel Locks
(This means you can't twist it off with a pair of pliers.
Then coat connections with bat. connection corrosion inhibitor. The
little treated felt rings work great also. Both are best.
Check that any wire crimps are tight. When in doubt "Change em Out".
Replace and recrimp or solder with rosin flux solder and clean
thoroughly after soldering.
.Also check for loose or corroded connections on terminal strips.
Don't use solid wire with crimp on terms. Note: Good quality marine
grade wire has a better coating, more and finer strands of wire for the
same gauge (makes it more flexible) and a coating on the strands
themselves to negate corrosion. Yes there is a difference. Get the good
stuff..
Be sure to check the other half of the circuit The ground return line.
It handles just as much current as the hot side.
This might be a great time to check all your bounding and make yourself
a nice fat ground system with BIG WIRE return busses run to selected
areas.
Read up on bonding and make sure your shaft is included. "This is a
whole nuther topic."
f you don't consider this you will be subject to Pitting of your Cutless
bearings and other expensive stuff..
Check any fuses and holders for loss of tension and if a glass type
fuse looks sagged, replace it. It might be acting as a nice current
limiting resistor and the sneaky devil is thinking of "Blowing out
anyway" at the worst time...
This type of problem is evident whenever lights dim when the galley pump
is running and things like the VDO Tach's, hour meter clicking another
tenth and all the instruments on the panel jump. (The reason turned out
to be the ground return was jumpered from from bracket to bracket to
bracket fed with #16 wire.)
I ran # 14 from each inst. to a ground bus and all is well...
Although this approach will not solve all problems, you will see great
improvement.
When it comes to current flow and good connections.
Like the old lady said while her husband was drowning, "Every Little Bit
Helps"
Class Dismissed!
David "Cooter Vrablic (Keeper Of The Holy Place)
MT36DC MYLO V ( My Last One # 5)