DC Rectifier

"TR"

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

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

Some Googling may help finding

petrus bitbyter

Its nothing new. You are always absurd.

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.

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?

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

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

: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.

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.

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.

Hope this helps. Mark.

: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

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.

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.

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

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

"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:

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

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

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

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.

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

Exactly wrong, Vf drops with temperature.

Exactly.