DC Rectifier

Work on a workboat. Installed as our 24 volt DC system for control and lighting is a 240 VAC input / 24 VDC 120A output rectifier with battery backup. The rectifier has failed. Was a home built job from nearly 20 years ago. The builder I believe (Lynden) has since passed on. Would appreciate it if someone could recommend a company in Australia that could supply something similar. Many thanks. TR.

Reply to
TR
Loading thread data ...

"TR"

** So "Lynden" is/was a bloke's name ??
** Similar to what ??

A home made unit that only the OP knows anything about ??

Who can see the absurdity here ??

Maybe the OP can get his arse in gear enough to post a pic of the original.

..... Phil

Reply to
Phil Allison

"TR" schreef in bericht news:0aSdnWTpM7jeTTnXnZ2dnUVZ snipped-for-privacy@netspace.net.au...

Some Googling may help finding

formatting link
for instance. This one is in the USA but Google on.

petrus bitbyter

Reply to
petrus bitbyter

Its nothing new. You are always absurd.

--
You can\'t have a sense of humor, if you have no sense!
Reply to
Michael A. Terrell

I'm not in Oz, but I would see what is availible for motorhomes or RVs. They are common items in the USA. The first thing you need to do is find out what output current you need.

Some older supplies were nothing more than a transformer and a pair of high current diodes. They are unfiltered, but rorked OK with lights and pumps.

--
You can\'t have a sense of humor, if you have no sense!
Reply to
Michael A. Terrell

Better quality battery charger? Plenty of 240V to 24V power supply manufacturers around. how much power are you talking about? where does the 240V come from in the first place?

Reply to
terryc

:where does the 240V come from in the first place? :

The workboat will have its own 240Vac generator operating from the diesel motor...

Reply to
Ross Herbert

:Work on a workboat. Installed as our 24 volt DC system for control and :lighting is a 240 VAC input / 24 VDC 120A output rectifier with battery :backup. The rectifier has failed. Was a home built job from nearly 20 years :ago. The builder I believe (Lynden) has since passed on. Would appreciate it :if someone could recommend a company in Australia that could supply :something similar. :Many thanks. :TR. :

The system you describe is essentially the same as would be used for a telecommunications network power supply with a float charged battery.

Typical power supplies of this type are quite expensive but I would suggest a 3U version might fit your application. The 50-200A 3U version might be suitable.

formatting link

Reply to
Ross Herbert

Err, why? what are you running off this that needs 240Vac? Wouldn't it be easier to just run a 24V(battery bank voltage) generator off the motor and save all the problems of bringing it down again?

If it is small current 240V, then 24V to 240v inverters are common and cheap.

Reply to
terryc

Hi there,

Try Woods Electric. They specialise in large chargers like you are looking for.

Check out this link for the Neptune range of chargers. it may be just what you want.

formatting link

Hope this helps. Mark.

Reply to
Art Vanderlay

:On Tue, 08 Sep 2009 02:40:53 +0000, Ross Herbert wrote: : :> On Tue, 8 Sep 2009 01:27:52 +0000 (UTC), terryc :> wrote: :> :> :> :where does the 240V come from in the first place? : :> :> The workboat will have its own 240Vac generator operating from the :> diesel motor... : :Err, why? what are you running off this that needs 240Vac? :Wouldn't it be easier to just run a 24V(battery bank voltage) generator :off the motor and save all the problems of bringing it down again? : :If it is small current 240V, then 24V to 240v inverters are common and :cheap.

Boats which are out to sea for more than a week at a time need facilities to make for a more comfortable work environment. Access to everyday electrical appliances help make this possible. It is much cheaper to equip the boat with

240V appliances than to buy lower voltage units generally designed for caravan and RV use.

I admit I don't know whether the OP's workboat has a 240Vc generator but I have done work on a fishing boat which did have this capability. 10 years ago it was common to have a 240V generator added when the boat was being built but I think that on more modern boats there is a trend towards using large capacity DC-AC inverters rather than a rotating alternator to produce the 240Vac.

Reply to
Ross Herbert

Aah, work boat in the sense of a fisherman working on a fishing trawler or similar, rather than a portable workshop boat.

As you point out, the devil is in the detail and how the power is used for what purpose.

Reply to
terryc

stick welder?, but you can get 35amp rectifiers from jaycar or dick smith. you can join 5 of them together in parallel which would give you 175 amp, they would probably cost $5 each? approx Just a thought! John

--
Posted at www.usenet.com.au
Reply to
moffie

Wouldn't work. The one with the lowest Vf would explode, then next lowest, & so on.

--
    W
  . | ,. w ,   "Some people are alive only because
 Click to see the full signature
Reply to
Bob Larter

"The one with the lowest Vf would explode, then next lowest, & so on"

Which should give you a clue on how to proceed down that path - add a very low ohm resistor in series with each bridge (something in the order of the hundredths of ohms range) so that the worst current hog only gets a maximum of 35 amps. At this current the resistors are still going to be physically big or very numerous.

or you could try this:

formatting link

but seriously, if you have any doubts you should get someone to look at the thing for you.

Reply to
David Eather

Nuh, the resistors have to be in series with each individual diode.

Reply to
Bruce Varley

I've got to say I don't agree.

Reply to
David Eather

y

years

ate it

old

th. you

So match the Vf's best as possible using a test rig. If one diode junction heats up due to extra current, its Vf rises a bit, and then the other diodes would share the extra current. Its self equalising.

The best solution is actually to use one suitably rated diode.

Reply to
glenbadd

glenbadd wrote in news: snipped-for-privacy@g1g2000vbr.googlegro ups.com:

Exactly wrong, Vf drops with temperature.

Reply to
GeoffC

Exactly.

--
    W
  . | ,. w ,   "Some people are alive only because
 Click to see the full signature
Reply to
Bob Larter

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.