Unfortunately I don't...
I may be able to get my hands on 2 magnetic ballasts with suitable specs but the downside is that they will be able to drive multiple fluorescent lamps. I guess I could look at those and posts the specs before I buy them.

The whole idea behind this is that I am looking for find an alternative ballast for a certain amount of vintage Euro-fixtures (Philips/Schreder/Hogro etc.) I collected over the years. Most of them came with 80 Watt MV bulbs + magnetic ballasts.
I can get those ballats to work using a step up converter (120 to 220 Volt converters). However I find this very inconvenient and do not know how this is going to work in the long run.
I know I could simply replace the lamp socket and and bulbs + ballasts for American spec ones but I'd like to keep them original especially sinds all bulbs still work and I love the 80 MV bulbs.
Also, I love the challenge to finding a suitable solution for this

Ballasts that have wires for the lamp separate from the power input pose a challenge (there is possibility to short the internal heating coil, so to avoid that you must check which one of the same-colored wires connects to which end of it in the ballast - a lot of multimeter work, and if you dont find out then you won't be able to use the ballasts)

But i think it should be possible to find, and in that case you may be able to use eg 2 ballasts for 2x40w each to power 2 80w lamps (each lamp is connected to the outputs of 2 ballasts in parallel, eg 1 lamp takes the blue from both ballasts and 1 the red from both ballasts), so if you can wire 2 lanterns to the same ballast box then this may be advantage for you

So long as you use 120-240 converters of sufficient capacity (with some safety margins for the lamps higher power use during warm up etc) it should be ok, the lamps will just be a bit underpowered due to the 50-60 Hz difference but i hope they wont be underpowered too far (and maybe you can use 130v etc or 240v instead of 220v converters to up the voltage as much as you can to compensate)

Or you can (i dont know if it is ok by the code, but tbh i dont know if the ballast hacks are ok either) just use 240v from 2 phases (again this will cause a bit underpowering due to the 60 Hz, hopefully not too bad). If you have access to 277v you can try that - power it up and measure the current after warm up, see if it is right

If you go on using the lanterns with their orignal gear on 240v 60 Hz you'll probably have to disconnect the PFC capacitors if there are any, youll need lower capacity for proper power factor correction on 60 Hz anyway, and the original ones might not be rated for 60 Hz though i dont expect them to get damaged even on 60 Hz but i dont know what their design margin is (for the highre current that will be at 60 Hz). On 277v you'll definitely have to disconnect them as they are not built to hold 277v

ok I will look for 2 ballasts (in case I can't find the single ones) that can power 2 lamps each 40 watts.

As for the 120-240 converters, here are some numbers.

I wired up my Philips 80 Watt MV ballast + bulb.
After it fully started up, the ballast was drawing 79 watts with 0.74 A from the 120-240 converter (at 245 Volts).

I have no idea how much the ballast draws from a proper 240 - 50 hz outlet, probably more. This must be the underpowering you were referring to?

Just wondering, can I connect my 220/240 - 50 hz rated ballast to the outlet my dryer is connected to (a 240 Volts outlet)?

The undrepowering at 240v happens due to the ballast "ballasting more" at 60 HZ than at 50 Hz. It is intended to give about 800mA at 50 Hz and ideally will give 666mA at 60 Hz, actually it will probably give a bit more

If you get 740mA with the converter thats great, it sufficint power. You can keep using that

With the dryer socket you'll get about the same as with the converter (correct voltage but underpowered due to 60 Hz) if the voltage is lower than the 245 you got from the converter then it will underpower more. I think as long as its above 650-700mA is good (damage to the lamp happens if it is stuck in medium power mode and fails to complete its warm up, but if it warmed up well on the reduced power there is no problem)

ok thanks! So I cannot damage the original Euro- ballast by using either the converter or 240 dryer outlet (due to the fact its on 60 hz)?
As long as that's fine I will give it a try (connecting the 240-50hz rated ballast to my dryer outlet to see how much it will draw).

Yeah I measured 740mA that was drawn by the ballast when I used the converter. Mind you, this was measured using a kill-a-watt type of meter. So the setup was that I had my lamp connected to the Euro ballast, the ballast was plugged into my kill-a-watt meter, and the meter was plugged into the 120-240 converter.
I am not sure if this would be equivalent to what the lamp is actually getting (740 mA)? If this isn't the case, how can I measure that using a multi-meter (what settings do I need to use on the meter, and where do I place the measuring wires)?

Sorry for that question, I've only used a multimeter once to measure the Amps of my car battery..  


The funny thing is, that when I measured how much the converter is actually drawing from my 120 Volt outlet, I get very different numbers:

120 Watts
1.74 A

So the converter is drawing quite a bit more. I guess this is to compensate?
So here is the schema how I wired things up:




Thanks again, you've helped me big time already... and I learned a lot!

The ballast you cant damage for sure. The 60 Hz will cause lower current in it (so underpowering the lamp) and nothing else

PFC capacitors (if installed) will be a bit overdriven (at higher current) and actually "over correct" the power factor, creating bad power factor again in the other direction (leading), ideally you would want lower value capacitors for 60 Hz for proper PFC. So long as the existing capacitors are rated for 60 Hz thats ok for the capacitor (then you only have the bad power factor but it is not a cause for damage). If not rated for 60 Hz actually i still dont expect anything to happen, but there is no guarantee since you do run the capacitor out of spec "to the bad side". If unsure disconnect the PFC capacitor

Lamp can be damaged if run out of spec at too high current (that won't happen in our case), or if run at way too low current for long periods (minor underpowering is not a problem)



Here is a quick multimeter guide for you :


And what mistakes can blow up the multimeter and should be avoided :

 - In most multimeters the red wire is moved to another socket to measure current (in the 10A range or in all ranges depending on model). Be sure that the wire is pluged in the right socket on the multimeter before measuring current on voltage

 - Do not measure current across terminals of voltage source - you are making short circuit (sounds like you allready tried this one)

 - Do not measure current higher than the range selected on the multimeter

 - The test wires of most multimneters are thin - Do not measure currents of few A and more for too long as the wires can heat up and melt the isolation

 - Beware of voltages higher than the multimeter is rated for - Besides blowing the multimeter, the isolation of test wires is not rated for it either and you can get a shock. In lighting circuits such voltage is present in HPS and MH lamps which have ignitor

 - Do not measure resistance in circuit with voltage present (from power source, battery, charged capacitors etc)



Update for your edit :

The converter is an autotransformer (transformer with part of the coil shared between both primary and secondary sides), but the basics for it are same as a tramsformer, so the rules of "normal" transformers mostly hold for it as well

The transformer factor is defined as the factor between number of turns in the coils. Ex. IF the transformer have 80 turns primary and 160 turns secondary then its factor is 1:2

The voltage will be scaled by the same factor 120v --> 1:2 transformer --> 240v (more turns in coil make higher voltage for the same magnetic field)

The current is scaled by the same factor in reverse 3A --> 1:2 transformer --> 1.5A (more turns in coil make the current divide by the amount of turns for the same magnetic field, so lower current)

This is consistent with the role of the transformer : It converts power but it does not create power (no fre infinite electricity....) and (assuming it have no losses) it does not destroy power either. In our example the transformer is indeed getting 120v*3A = 360VA in and 240v*1.5A = 360VA out

This is consistent with what you get there, in fact you get numbers a bit off since the transofrmer does have losses so it takes a bit more power on the input which is wasted as heat

Thanks very much for that guide, that is very handy!

My bloody multimeter cannot measure AC Current I just noticed...