Ballast

[Guest clownfish4]

How do you make a 250w ballast?  I heard they are pretty easy but have no idea where to begin.

[krish]

Clownfish,

There are 2 types of ballasts.

a) Magnetic

b) Electronic

 

The magnetic ballast comprises of 2 types - the Probe Start

and the Pulse start type.

The magnetic ballasts are essentially an Auto Transformer

with either 1 or 2 capacitors.

 

The pulse start has higher voltage to fire certain types of

lamps.

 

The electronic ballast is solid state circuitry and is more

efficient due to its high frequency pulses and

provide a higher duty cycle. Don't even bother messing with

one, since it has high voltages and might require good heat

sinks to dissipate heat and may be test equipment as well.

This is if you want to build the circuitry from parts.

 

If you want to wind your own auto-transformer, then that

is an entirely different story.

 

You can however purchase the transformer/Capacitor as

a kit from say http://www.hidirect.com.

 

But on top of the purchase, you will need sockets, wires,

cabinet, screws/nuts, tools to rig it up and more important

time.

 

You can other wise go to say http://www.diyreef.com and

purchase one of their complete kit.

 

I went the DIY route for my first 250W dual ballast.

But for the

3rd one, i just bought the pre-built . The reason was

the price difference. When all you save is about say 20/30

bucks, it is not worth the time it takes to put one together.

 

However, my DIY ballast has fuses and Fan built into the

cabinet and the one purchased from the DIYReef does not

come with those extras.

 

Let me know if you have questions.

 

tnx

krish

[Guest tgallo]

wow krish, i think you coverd it well:) .

[michaelg]

There is a third type of ballast.

[ErikS]

The type Michael is referring to is called an "F" can. It's basically the coil & cap in a single unit.

irregardless

Psssst.....not a word. Sorry, couldn't resist.  :D

[michaelg]

thanks eric, for the F-can....  

Those things are real heavy, but nice and compact with far less exposed than a standard ballast.

 

I fixed my gramar above  

[ErikS]

definately do-able.

A quote from one of my posts, guess I win the "glass houses shouldn't throw stones" award  :D  :D

[pez]

F-Can ballasts are made for less-than-benign environments, as they are completely sealed (potted).  Again, they are generally tar ballasts in a sealed enclosure.  You might be able to get a potted electronic ballast, but I have never seen one for MH lamps.

 

Any electrical supply store will sell you a "can and core" ballast, from which you can fire mogul-based MH lamps.  You need to buy a special "HQI" ballast to fire the double-ended MH lamps.  I think standard MH ballasts are M-59; don't recall what the ballast is for a DE lamp.

 

-Tom

[krish]

If at all possible, it is better to mount the ballast away in a

location free of salt water splash.

Salt and electrical stuff, it is just a matter of time for things to

go wrong.

For a probe start ballast, you can keep it around say 6ft away.

The cord from the ballast to lamp needs to be around 6ft.

For a pulse start, it can be around 10ft.

One can look up the specs on http://www.hidirect.com for

the distance of the cord.

 

-krish