I'm heard from Ash that superimposed ignitors are connected to the ballast at the same way as 750V two wires parallel ignitors that designed to ignite the american probestart MH lamps with the European mercury ballasts and the Philips HPI-T and HPI-BU (That can also ignited with any type of HV ignitor being a pulse start lamp, but can also with a 750 parallel 2 wires ignitor because of the neon-argon that lowers the lamp starting voltage) but produces 4-5KV instead of 750V.
Is this is true that superimposed and 2 wires parallel ignitors are the same type of ignitors, except the different pulse peak voltage (4-5KV of superimposed vs 750KV of the 2 wire parallel ignitor), and that superimposed is actually a type of a 2 wires parallel ignitor?
Since in Israel, 750V two wire parallel ignitors aren't available, and probestart MH lamps (Either Venture Euro lamps or the US Osram Powerstar HQI-T 400W/N/SI or generic chinese MH lamps) enjoys huge popularity in Israel in installation that designed for pulse-start MH lamps, is this possible to start a probestart MH lamp with a mercury ballast and a superimposed ignitor without distroying the starting probe, because the ignitor is parallel? (Passive semi-parallel ignitors, will for sure distroy the starting probe)

Superimposed ignitors are something really different than the parallel and semiparallel ignitors.
However some superimposed ignitors may be connected and work as parallel ones ("Lamp" output to the phase wire to the lamp, "Neutral" to the lamp neutral and the "Ballast" input keep open), this connection mean the pulse voltage would be somewhat lower than in the superimposed connection, but not as much (so still able to cause unwanted discharge in the outer in lamps not designed for such high voltage ignition pulses).

With the probe start lamps and ignitors:
I do not see any reason, why the probe should be in any risk with any type of high voltage ignitor: Ignitor is nothing more, than rather high impedance high voltage source. So when the lamp ignite on 200V, there would never be more than 200V, even with 65kV instant restrike ignitor, as the lamp simply clamp the voltage. And this is valid not only for simple lamp with two electrodes (= pulse start), but as well with lamps with auxiliary probes (= probe start).
The problem is somewhere else: When the lamp arctube have higher ignition voltage (e.g. it is hot), the voltage from the ignitor reach either the ignitor's pulse OCV (= unsuccessful ignition) or the breakdown voltage of that hot lamp (it at least start flashing, eventually ignite the arc). So an MV probe start arctube with 2kV ignitor would actually form hot restrike setup (but other components of the lamp would be in danger).
But in the normal commercial lamp design, the arctube is placed in an outer bulb. And the outer bulb have some gas inside, as well as some metallic conductors. All the arrangement is designed so, the dielectric strength is above the maximum expected voltage from the ballast in all situations.

But applying voltages exceeding the dielectric strength form a make-shift discharge as well. But unlike the arctube inner cavity, the outer is not designed to host the discharge, so it usually lead to lamp destruction.
So the whole system should be designed so, such discharge in the outer could not happen in any state (so include the hot restrike attempt) during whole lamp life (after the EOL nobody care about the lamp functionality, as it already does not work), so it should not rely on the lamp limiting the voltage. The weakest spot does not have to be inside the outer, but e.g. in the common socket design (therefore HCI-TS need special sockets to work with hot restrike 25+kV ignitors)
So here is important, what starting given lamps are designed for:
- Tubular, double contact lamps are designed for >30kV, allowing hot restrike gear
- E27 or similar pulse start lamps are limited to few kV, so they could handle the ppulses of regular HV ignitors, but not anymore the "hot restrike" gear
- Most probe start lamps are designed to ignite with low voltage (<1kV) only, so their outer is usually not designed to handle the HV pulse, therefore you should never use them with the HV ignitor (any type, include the superimposed wired as parallel)

Medved: Thanks.

here in US the american probstart MH ballast is similar to the mercury ballast the only different between tbe probstart MH is it have higher OCV than regular MV ballast

that one reason probstart ballast is dual rated for MH and MV. MV ballast have lower OCV to strike the lamp
if you are using a choke ballast for MV I dont think you would have a problem ignighting the probstart MH
lamps since it OCV the line voltage.

funkybulb: 230V isn't enough to strike a probestart MH lamp reliably and instantly with a mercury choke ballast.
Sometimes a probestart MH lamp will strike directly from the 230V, but this is more an exception than a rule, and the lamp will lose the ability to strike with the 230V as it blackens. So this is a reason why when operating a probestart MH lamps with a mercury choke ballast, a 750V parallel ignitor should be used to ensure that the lamp will reach their expected lifetime and always strike in the first try.
The Philips HPI-BUS, on the other hand can freely be striked directly from the 230V mains with a MV choke, as in addition to the starting probe, the arctube gas filling is the neon-argon penning, which further lowers its striking voltage to that of the mains 230V frequency.
Also, unlike autotransformer ballasts (HX, CWA) which have variable OCVs, The OCV of all chokes is the same as the mains voltage.

The superimposed ignitor is caused "series ignitor". Thats for a reason : In a typical superimposed igntor with terminals LA, D, N the high voltage output is between LA and D. Those are wired in series with the ballast and lamp

The 750V ignitor is called parallel ignitor, as it is in parallel to the lamp. (a glow starter is another form of parallel ignitor). It does not by itself output any high voltage. All it does is to close and open a circuit through the ballast, causing inductive kick as the circuit opens

What you confused here, and you confused it in our discussion in the 1st place as well. is the difference between series and parallel connetion, leading to confusion between the "series ignitor" and "parallel ignitor". When i told you that series ignitor is the same as superimposed ignitor, you somehow confused it with the parallel ignitor being the same as superimposed



Any ignitor out there (superimposed, semiparallel and parallel) have 2 wires (LA and N) connected in parallel with the lamp. In all of them, the voltage is measured across the lamp to determine if it is lighting (so ignitor is inactive) or not ighting (so ignitor have to start it)

But the main path of current for either type of ignitor is what really determines its type :

Superimposed ignitor outputs high voltage between LA and D when it is actve, or presents a short between LA and D in other times. It is wired in series to the lamp and ballast - When it is active the high voltage circuit is formed on the same series circuit with the ballast and lamp

Semiparallel ignitor contains a capacitor which is charged in parallel with the lamp circuit, then discharged into part of the ballast coil. The ballast coil then acts as step up transformer to amplify the pulse. Its current path is parallel to part of the circuit, but not simply parallel to the lamp, and not series to anything, so it is called semiparallel

Parallel ignitor connects parallel to the lamp - The current through the "shorted" ignitor is going through the ballast, then the ignitor which is parallel to the lamp



Connection of superimposed ignotor is : LA (red in Eltam ignitors) - lamp, D (white in Eltam ignitors) - ballast output, N (blue in Eltam ignitors) - neutral

Connection of semiparallel ignotor is : LA (red in Eltam ignitors) - lamp and ballast output, D (white in Eltam ignitors) - tap in ballast, N (blue in Eltam ignitors) - neutral

Connection of parallel ignitor is just parallel to the lamp

Ash: Ah. I thought that parallel is טורי and not מקבילי, and series is מקבילי and not טורי.
Thanks.
Wonders why Eltam don't produces parallel ignitors generally. They are required for operating the current Eurolux MH lamps (Which are probestart MH lamps), the US Osram HQI-T 400W/N/SI and the Venture Euro lamps.
Otherwise, autoregulator ballast is the only option for them.

Anywhere the parallel ignitor can be used, the superimposed can be used as well (same ballast, different connection) and run Pulse Start lamp

So there are little or no uses where the parallel ignitor is the only option

Many Probe Start lamps (meant for CWA or parallel ignitor) are in fact used on inappropriate Pulse Start gear here, though i never seen this to cause a problem (maybe besides lamp life)

Ash: When operating a probestart MH lamp that its frame aren't designed for HV and its atmosphere have sufficient low voltage to ionise, with a superimposed and semi-parallel ignitors, an unwanted external discharge may be developed in the lamp envelope during a hot restrike, what leads to lamp distruction.

This is what they say, but i never actually seen it happen

Probe lamp with HV ignitor: With normal operation (=starting only cold lamps) the discharge does not develop in the outer, as the arctube ignition prevent the voltage from building up.

Parallel vs semiparallel vs superimposed (or serial, if you want):
All of them could be made for any required pulse voltage, provided the ballast could handle that voltage.
I've seen 5kV parallel ignitors, what use C-D multiplier string using the lamp connection via a separation resistor to charge the capacitors to the high voltage, when the auxiliary spark gap triggered, it connected the charged capacitors to the same lamp connection.

Superimposed ballasts use the capacitor precharged by a resistor, then discharged to the pulse transformer primary. The ballast winding may be used as the pulse transformer, so a tap is required. But this require the tap to be on very short section - about in 5% to get >3kV on 230V (so with 200V available on the capacitor) and the energy or pulsing frequency is rather limited (otherwise the charging resistor would dissipate too much). I have seen this concept only with US ballasts (use the ballast winding as a pulse transformer) and in superimposed ignitors (use separated pulse transformer). All chokes intended for semiparallel ignitors have the tap in 20% of the winding, what would yield only 1kV pulse with this concept, so (at least with the chokes I've seen) not used on 230V.

Then many ignitors use the resonance effects to charge capacitor to higher voltage and so generate the pulses. It is implemented as a capacitor in series with a triac, all that connected behind an inductance (either full ballast length for parallel, or the 20% section of the semiparallel ignitors). It work as follows:
- During the mains peak the triac fire, connecting the capacitor to the mains via the inductance. An LC circuit is formed, making a 1/2 period on it's resonance frequency - as the triac turn OFF when the current crosses zero. But at he same time the capacitor become charged to twice the mains peak voltage (the mains peak + the difference between the mains peak and the capacitor voltage before the triac triggered, so after first pulse another mains peak value). So the capacitor remain charged for twice the mains peak voltage, so about 600V for 230V mains. At the same time, this 600V appear as pulse on the connection to the ballast (tap for semiparallel, the lamp on the parallel), sometimes already igniting the lamp. But now assume the lamp does not ignite.
- Then text mains half cycle the triac fire again in (or near) it's peak value. This time the difference between the capacitor and mains voltage is -300 - 600V = -900V, so this get reflected around the -300V of the mains, so the circuit could yield -1200V (so quadruple the mains peak voltage). With semiparallel ballasts the 900V is then eventually seen by the "20%" ballast section, so the ballast output pulse could be then 300+5x900=4.8kV.
- If this would continue, the pulse values (on the igniter, not transformed by the ballast, so on only parallel ignitor) would follow as +1.8kV, -2.4kV, +3kV, -3.6kV, +4.2kV,... (assume all the components could handle the voltages).
In real life, as the capacitor voltage increase, the triac triggering is advanced so, the pulse amplitude is stabilized on the predefined value (so e.g. 700V with SN57, so 5kV pulses when transformed by the ballast coil turn ratio).
This method charge the capacitor without any major losses (compare to the charging resistor of the superimposed ones), so the energy there is virtually not limited, so it is used for long range ignitors.
But as it require quite high inductance (to build up the voltage across the capacitor), it is not practical in the superimposed ignitor form.
And generating the HV directly (so as a parallel ignitor) would require multi kV rating of both the triac, as well as the capacitor, so not practical either.
So this is used mainly in the semiparallel form for HV lamps (e.g. SN57) or parallel form for LV (so below 1kV) ignition pulse lamps.

The only ignitors using the flyback voltage pulse (generated by interrupting a switch after the ballast) I've seen or read about are either the thermomechanical switches (either glowbottles used in Osram selfstarting HPS, or bimetal switches Tesla used in ther selfstarting lamps), most frequently as internal ignitors (but sometimes used even as external ignition devices)

And there is one other method (used solely by the Iwasaki): Using highly nonlinear capacitor parallel to the lamp:
Below some voltage level the capacitor have high capacitance (10's of nF), but when the voltage exceed some level, the capacitance suddenly drop to a fraction. When this is connected in series with an inductor (= the ballast choke, when the lamp is not yet lit), the capacitor create a current required to charge it. But when reaching the critical voltage (~200V for lamps intended for 230V mains with series choke), the capacitance drop, so the curent disappear. This sudden drop in the current then create a HV spike on the ballast inductance, igniting the lamp. The nonlinearity in the capacitance is achieved by using material, that could saturate it's electrical dipoles by electric field all at the same moment and way prior to it's breakdown, so described as a "ferroelectric" material (name borrowed from the "ferromagnetic", but unlike the magnetic, it have nothing common with the iron).
I think this is patented by Iwasaki (for sure it was, but I don't know, if the patents are still alive today) and as the ferroelectric elements degrade, it is usable only as internal ignitors. Well, Iwasaki use it only as internal ignitors, as it could be made in the form of rather small ceramic disc, so encloasing it into the vacuum outer is easier than to protect it against elements in the form of a separate ignitor.