Salvo Question...

[Twinsetmad]

Hi.. I'm interested too... and have some questions, to ask the experts.

Looking at the Havoc and Rebel lights, the only differences I can see is with the Havoc, is the Ballast is in the battery housing where as in the Rebel both the ingniter and ballast are in the torch head.

Firstly.... whats a ballast..? and what benefits does one have over the other...?

Thanks...

[pieater]

A Ballast does "things" to the current from the battery. Don't know what, but you need a suitable "ballast" with a HID.

IMHO, the more ballast you can get in the canister the better as the lighthead you have to hold will be smaller.

[Reikimaster]

Originally Posted by Twinsetmad

Firstly.... whats a ballast..? and what benefits does one have over the other...?

Thanks...

good question, and i will wait for the correct answer, my assumption has always been that its a capacitor type think that regulates the output to the bulb, thus preventing burning the bulb out with surges.

[wreckweasel]

Your bulb is an arc lamp, to make it arc you need a voltage in the thousands of volts range. The ballast steps up the 12 or so volts from the battery.

[weazelz]

Electrical ballast - Wikipedia, the free encyclopedia

[pauldiving]

a ballast creates enough charge to strike the bulb and regulate constant voltage to the hid bulb,

there are two types, electronic and wire magnet like a transformer

brightstar made in china supply a lot of these units as well as making good hid bulbs...

[Rookie]

Guessing here, but does the ballast in the head mean you can swap the head for a different type buld, e.g.LED??? Ballast in the canister would prevent this I guess.

Phil

[robf]

The main purpose of the ballast is as a current limiting device. When the light is off there is no physical connection between the electrodes in the bulb. To strike an arc takes a couple kV as an earlier poster said. Once a plasma is established (i.e. bulb is producing light) to all intents and purposes there is now a 'connection' between the electrodes. Without a ballast this is basically a short circuit and the current will keep trying to increase and increase - eventually knackering the battery, bulb and wiring. The ballast controls the current and keeps it steady. The simplest type of ballast is a resistor - but they are very inefficient and get very hot. The ballasts in these types of light are electronic ones IIRC and are a lot more efficient....

Ballast is specific to the type and rating of the bulb - so you can't swap to LED and use the same ballast as for HID. Do LED even use ballast....?

Right.....enough of that. Off to the pub for lunch and then drive to Weymouth

Rob

[pauldiving]

i flooded mine last weekend!

going to splash my cash to phil for a new one, pick ya phone up phil!!

[Sparky750]

Originally Posted by robf

The main purpose of the ballast is as a current limiting device. When the light is off there is no physical connection between the electrodes in the bulb. To strike an arc takes a couple kV as an earlier poster said. Once a plasma is established (i.e. bulb is producing light) to all intents and purposes there is now a 'connection' between the electrodes. Without a ballast this is basically a short circuit and the current will keep trying to increase and increase - eventually knackering the battery, bulb and wiring. The ballast controls the current and keeps it steady. The simplest type of ballast is a resistor - but they are very inefficient and get very hot. The ballasts in these types of light are electronic ones IIRC and are a lot more efficient....

Ballast is specific to the type and rating of the bulb - so you can't swap to LED and use the same ballast as for HID. Do LED even use ballast....?

Right.....enough of that. Off to the pub for lunch and then drive to Weymouth

Rob

What he said