24v to 13.8v DC/DC converter

[KD2GOE]

when i was camping i was having power trouble running my TS-450sat on 1 12v deep cyl battery Manley audio was not sounding good at full power but sounds fine when running off my 13.8 PSU this was verified at home. keeping the car running is not an option...
i was thinking of ganging up 2 smaller 12v deep cyl battery's and running a steep down converter....
has some one done this?
and what converter did you use? i am going to guess this may have the same trouble as a bad switch mode PSU with hash if it is junk.

i was even thinking of running a power inverter but there is the same trouble with hash on them

 

[Captain Kilowatt]

All you need is a simple linear type regulator with some pass transistors on a heat sink. An LM317 regulator adjusted to 13.8 volts feeding several 2N3055 pass transistors will be 100% noise free because it is a liner type device and not digital switching. Each pass transistor will handle 7-8 amps easily but you need a good chunk of heatsink. This is easy to do but highly inefficient as the excess power consumed is simply converted to heat. Might want to add over voltage protection however as a shorted pass transistors puts the full 24 volts into the rig.

 

[Beetle]

I'd put the batteries (2 or more good ones) in parallel rather than in series. The voltage won't drop as severely as with just one, and the available current will of course increase with each battery.

 

[KD2GOE]

All you need is a simple linear type regulator with some pass transistors on a heat sink. An LM317 regulator adjusted to 13.8 volts feeding several 2N3055 pass transistors will be 100% noise free because it is a liner type device and not digital switching. Each pass transistor will handle 7-8 amps easily but you need a good chunk of heatsink. This is easy to do but highly inefficient as the excess power consumed is simply converted to heat. Might want to add over voltage protection however as a shorted pass transistors puts the full 24 volts into the rig.

I did think of doing this but put it on the side due to how inefficient it is..

 

[Singularity35]

I'd put the batteries (2 or more good ones) in parallel rather than in series. The voltage won't drop as severely as with just one, and the available current will of course increase with each battery.

Agree that parallel is the way to go. Same voltage, more current.

 

[Captain Kilowatt]

I'd put the batteries (2 or more good ones) in parallel rather than in series. The voltage won't drop as severely as with just one, and the available current will of course increase with each battery.

I thought of that too but depending on the state of charge and the voltage tolerance of the radio plus voltage drop in the wiring he may not get as much extra operating time as you would think. Since he is looking at two batteries anyway he should just try it and see if it lasts as long as he wants and if it does great and if not then look at the alternatives.

 

[DainBramage]

I thought of that too but depending on the state of charge and the voltage tolerance of the radio plus voltage drop in the wiring he may not get as much extra operating time as you would think.....

heck, just get one of those small Honda generators, use a batt charger/power supply.

they are CHEAP , you can barely hear them when they run, and.... they will power an elec coffee pot too.

 

[binrat]

heck, just get one of those small Honda generators, use a batt charger/power supply.

they are CHEAP , you can barely hear them when they run, and.... they will power an elec coffee pot too.

MMMM coffee.
DB, if you would have posted this last week I would have not believed the idea. But during field day there was a Honda running around the corner about 25' away from my station. Never heard it while I was operating and only slightly when not.

 

[KD2GOE]

well i guess my way of thinking was dropping 24v down to 13.8 would be way more stable.

 

[KD2GOE]

heck, just get one of those small Honda generators, use a batt charger/power supply.

they are CHEAP , you can barely hear them when they run, and.... they will power an elec coffee pot too.

i was thinking of that to but it needs to be dead quiet ill i would need is 1,000 watts or less and coffee sounds good!
i was looking at some of the Honda generator $1.000 that's a lot of money ill have to save up for that... or fined one used.

 

[tba02]

Mayberry's usually has the best price around if ordering new.
http://www.mayberrys.com/Honda/generators/eu2000.aspx
Wise sales is the other major seller.
I love all 3 (yes 3) of mine.

ETA: the price difference between the EU1000 and EU2000 is 100 bucks, and is worth it.

 

[KD2GOE]

Mayberry's usually has the best price around if ordering new.
http://www.mayberrys.com/Honda/generators/eu2000.aspx
Wise sales is the other major seller.
I love all 3 (yes 3) of mine.

ETA: the price difference between the EU1000 and EU2000 is 100 bucks, and is worth it.

we get a lot of snow here in the winter and the power has grown out sooo.... i maybe able to convince the Wife this is a good idea

 

[binrat]

If you get a larger sized Honda, they have an eco mode which is very quiet and at "idle" puts out 500 watts, when the draw is higher the engine increases rpm's for the draw.

 

[DainBramage]

we get a lot of snow here in the winter and the power has grown out sooo.... i maybe able to convince the Wife this is a good idea

I had power go out for over a week, it does happen.

how many $$ do you have in your freezer?

 

[Captain Kilowatt]

Those small EC1000/2000 are indeed quite expensive. For a small generator the inverter type are the best as they run quiet and have nice VERY clean power. I think the EC1000/2000 may be the inverter type but not sure.

I agree with the quality of the Honda engines and generators. I have a generator built by an Ontario company called Wallenstein. They make all sorts of generators and gas powered pressure washers etc. They use Honda engines on all their products. My generator is a 6500 watt continuous/7200 watt surge unit with a 13 Hp. Honda electric start engine. It was expensive but quality is. The engine alone costs more to replace than a complete Champion brand generator unit of the same supposed rating. I say supposed because the rating is the same but it has a smaller engine and alternator unit.