Metal Halide Lamp Ignitor

Have you looked on Google?

Sir,

What you actually mean by IGNITOR.

MH lamps start when their ballast supplies a high starting voltage higher than those normally supplied to the lamp electrodes through a gas mixture in the arc tube. The gas in the MH arc tube must be ionized before current can flow and start the lamp. In addition to supplying the correct starting voltage, the ballast also regulates the lamp starting current and lamp operating current. (See "What types of ballasts are available to use with metal halide lamps?").

Are you referring to BALLASTS. Please clarify

my question is about the ignitors in metal halide lamps and not about the ballasts . i know solid state ballasts are different but i am talking about the ignitors being used with electromagnetic ballasts ( chokes) . i want to know how the ignitors give pulse to the ballast to give the inductive kick needed for the lamp to fire

is there any thermal bimetallic strip found in the starters of fluorescent lamps or is it something else. there is a tickling sound coming from ignitors indicating there is a make break mechanism inside........ wht exactly is that

.practically if someone can help, it would be great. i have googled it already but only theory there nothing practical explanatin.

There are two schemes for HID igniters that I am familiar with. Note though, that where I live we have 240V mains, and so the ballasts for HID lamps are almost always a simple choke/coil, whereas in countries with 115V mains the ballasts are usually transformer-types.

The old-school igniters relied on a tapped ballast, with the tap closer to the supply end of the choke. The igniter draws current through the tap and then breaks the current, and the choke functions as an autotransformer to produce a starting pulse to the lamp.

The more modern approach is the superimposed pulse igniter. This wires in between lamp and ballast and contains all of the electronics, pulse transformer etc to create the ignition pulse independently of the ballast. I have seen two styles of these - one has just two terminals, one goes to neutral and one goes to the lamp/ballast connection. The other has 3 terminals, neutral, ballast and lamp.

thanks paul for your info.... but i wanted to know about the internal construction of an ignitor.... what sort of electronic circuit it uses, or if not electronic, what sort of mechanical arrangement is used inside...... relay/ bimetal strip... what exactly. if someone has broken an ignitor or knows the practical circuit.... can answer my query.

actual components of an ignitor needs to be known rather than its working theory

paul i have voted one good answer for you. thanks again.

Most of the igniters that I have seen have been potted which makes them next-to-impossible to dismantle for a look inside. I do, however, have a few educated guesses as to what is inside them.

There is usually some sort of pulse transformer that supplies the ignition pulse, and some electronics which control the pulse generation. Usually there is some control built in to sense if there is a lamp present and if it has ignited, so that the igniter does not try to ignite and empty lamp socket or an already-lit lamp tube.

Some of the 3-terminal igniters seem to be matched to a particular lamp size, and measure lamp current, switch off if the wrong size lamp tube is fitted.

thanks again paul, i am searching exactly for the same............ anatomy of an ignitor... failed to find any good link .

i wish i could get to know the internal components of an ignitor....