Good step up converter?

[Jason_Tan_]

Can anyone recomend me a reliable and inexpensive step up voltage converter? (110v to 240v) I will be using it for a lamp so its not going to draw that much power. Thanks in advance!

[mariushm]

If it's just for a lamp, you should first think if you really need a converter.

 

Most lamps using incandescent light bulbs simply use a small classic transformer to take 230v+/-5% AC (or 240v as you say it) down to 12v AC or whatever the voltage of the lightbulb is. In this case, you may be able to simply replace the transformer with a 110v to 12v one (or whatever the voltage of the bulb is).

I currently have a very common desk lamp that uses 12v 20w light bulbs and there's just one basic transformer in the base of the lamp, with just the right amount of weight to make the lamp feel right..

You may not even have to buy a different transformer , you lamp may be built with a transformer that may have two 110v AC primary windings connected in series ... by connecting the windings in parallel, you'd convert your 230v transformer to a 110v transformer - this is often done by companies selling products in various countries..

 

If the lamp is using a LED based bulb, then 99% of the time the lamp has a led driver inside which takes the AC voltage, converts it to DC and then a switching regulator type led driver circuit board makes sure the LED always receives the proper voltage and current.

Most such led drivers if they're the kind that runs directly from mains voltage, generally support a wide range of voltage at the input, so they may support 110v AC as well.

Sometimes, the lamps use led drivers which can handle only a low amount of voltage at the input, let's say 80v AC ... in such cases, sometimes manufacturers use cheap ways to reduce the AC voltage down to something like capacitive droppers (a capacitor and a resistor, see   https://bobparadiso.com/2015/02/03/capacitive-dropper/ ) to take the 240v AC down to under 80v AC and then the led driver would produce the right voltage for the lamp.

In such case, it would be as simple as replacing the capacitor with another value capacitor and/or changing the resistor

 

You should open the lamp and see the circuit and maybe take some pictures and / or post them here , write here how the lamp is made.

 

It may be possible to make it work on 110v with just a few small hacks instead of forcing you to buy some cheap and low quality inverter/voltage booster

 

 

[Jason_Tan_]

On 2/16/2017 at 10:45 AM, mariushm said:

If it's just for a lamp, you should first think if you really need a converter.

 

Most lamps using incandescent light bulbs simply use a small classic transformer to take 230v+/-5% AC (or 240v as you say it) down to 12v AC or whatever the voltage of the lightbulb is. In this case, you may be able to simply replace the transformer with a 110v to 12v one (or whatever the voltage of the bulb is).

I currently have a very common desk lamp that uses 12v 20w light bulbs and there's just one basic transformer in the base of the lamp, with just the right amount of weight to make the lamp feel right..

You may not even have to buy a different transformer , you lamp may be built with a transformer that may have two 110v AC primary windings connected in series ... by connecting the windings in parallel, you'd convert your 230v transformer to a 110v transformer - this is often done by companies selling products in various countries..

 

If the lamp is using a LED based bulb, then 99% of the time the lamp has a led driver inside which takes the AC voltage, converts it to DC and then a switching regulator type led driver circuit board makes sure the LED always receives the proper voltage and current.

Most such led drivers if they're the kind that runs directly from mains voltage, generally support a wide range of voltage at the input, so they may support 110v AC as well.

Sometimes, the lamps use led drivers which can handle only a low amount of voltage at the input, let's say 80v AC ... in such cases, sometimes manufacturers use cheap ways to reduce the AC voltage down to something like capacitive droppers (a capacitor and a resistor, see   https://bobparadiso.com/2015/02/03/capacitive-dropper/ ) to take the 240v AC down to under 80v AC and then the led driver would produce the right voltage for the lamp.

In such case, it would be as simple as replacing the capacitor with another value capacitor and/or changing the resistor

 

You should open the lamp and see the circuit and maybe take some pictures and / or post them here , write here how the lamp is made.

 

It may be possible to make it work on 110v with just a few small hacks instead of forcing you to buy some cheap and low quality inverter/voltage booster

 

 

The lamp I own is a very basic one, and I dont believe that are any of these circuits inside. It uses a normal light bulb but I actually want it to work with my Phillips Hue light bulbs from Europe. The bridge works fine here with the voltage difference, however the light bulbs dont work at all. What could I do?

[Silverwolf_7]

What kind of lamp runs off of 240VAC(I'm assuming its AC not DC)? Use a step up transformer. Just remember that if voltage is increased,current will decrease to keep an equal amout of power on each coil of the transformer(no free energy).  Alot of electric dryers run of 240VAC so one of those outlets may work. Or if don't have a 240VAC outlet you can get a 2-pole 240v circuit breaker for your electrical panel to pull 240VAC from it. Panels divide incoming voltage onto 2 busbars which are 110-120 VAC each, recombining the voltage gives you 240 volts again. Just don't go poking around your electrical panel unless you know what you are doing.

[Jason_Tan_]

30 minutes ago, Silverwolf_7 said:

What kind of lamp runs off of 240VAC(I'm assuming its AC not DC)? Use a step up transformer. Just remember that if voltage is increased,current will decrease to keep an equal amout of power on each coil of the transformer(no free energy).  Alot of electric dryers run of 240VAC so one of those outlets may work. Or if don't have a 240VAC outlet you can get a 2-pole 240v circuit breaker for your electrical panel to pull 240VAC from it. Panels divide incoming voltage onto 2 busbars which are 110-120 VAC each, recombining the voltage gives you 240 volts again. Just don't go poking around your electrical panel unless you know what you are doing.

Yes, it is an AC lamp. I will not be able to connect it to the dryer outlet so then I guess that in order for it to work I will need to get a 240v circuit breaker? I am not experienced in this at all and dont really know what I am doing. Is there a guide or something that I could follow?

[Silverwolf_7]

Can you show us the lamp. I've never heard of a lamp that runs off 240volts. 240 is usually reserved for high power devices to get the same power without drawing alot of current.

 

[Jason_Tan_]

14 hours ago, Silverwolf_7 said:

Can you show us the lamp. I've never heard of a lamp that runs off 240volts. 240 is usually reserved for high power devices to get the same power without drawing alot of current.

 

This is the lamp that I am using. I tried using the hue bulbs inside this lamp and in the light socket for the room and they don't work with either. Sorry for my lack of understanding

[Silverwolf_7]

If this is related to your previous post about the UK phillips hue bulbs not working in the US then I'd say to just get new fixtures in the US that run on 120VAC. Jury rigging electric devices that will be plugged in for the majority of their life isn't a good idea. In the long run it will be cheaper to just get new lights rather than have your house burn down because you didn't wire something properly or the new part fails for some reason. In addition any outlet cannot according to code, be converted from 120 to 240. Additional wire of the proper gauge and receptacles rated for 240VAC must be installed to safely carry the higher voltage. Some devices may have a switch (such as pc power supplies) that allows the user to select the voltage being used. 

 

[Jason_Tan_]

2 minutes ago, Silverwolf_7 said:

If this is related to your previous post about the UK phillips hue bulbs not working in the US then I'd say to just get new fixtures in the US that run on 120VAC. Jury rigging electric devices that will be plugged in for the majority of their life isn't a good idea. In the long run it will be cheaper to just get new lights rather than have your house burn down because you didn't wire something properly or the new part fails for some reason. In addition any outlet cannot according to code, be converted from 120 to 240. Additional wire of the proper gauge and receptacles rated for 240VAC must be installed to safely carry the higher voltage. Some devices may have a switch (such as pc power supplies) that allows the user to select the voltage being used. 

 

I was searching online and found this on amazon: 

https://www.amazon.com/VCT-VT-100UK-Converter-Transformer-Products/dp/B000N54DGO/ref=cm_cr_arp_d_product_top?ie=UTF8 

The lamp that I have here was purchased in Europe will work with the different voltage. Do you think that this converter will work as it would be cheaper than buying new lights?

[Silverwolf_7]

It should but it has a 100watt peak maximum capacity so assuming your light consumes less than 80-90watts it should work.

[mariushm]

Technically, the incandescent light bulb is in the same category as those appliances that are mentioned in the description... it's a constant load.

Also, those converters produce a "choppy" output, which luckily is filtered by switching power supplies of devices they recommend that product to be used with (chargers, shavers etc) but with a light, you may see flickering and the bulb may die prematurely.

 

The safest would be to use a regular (isolation) transformer. You can buy one that has a 230v primary or two 110v primaries (which you'd connect in series to get 230v) and 110v on the secondary side... and you'd simply use it in reverse, treating the secondary side as primary feeding 110v AC in it, so you'd get 230v on the other side.

 

Here's a bunch of them - filtered all that can do 50VA  or above (50w for lamps, less for other devices). Just have to pick one that has a  1:2 ratio between the sides, as in one side can be configured to 110v or 120v and the other side to 220-230v . Then you'd only need a plastic box, a mains plug and a cable and a wall socket to screw on the plastic box (or a power strip to cut the plug from it and connect the cable directly to the transformer)

[Jason_Tan_]

On 2/18/2017 at 11:07 PM, mariushm said:

Technically, the incandescent light bulb is in the same category as those appliances that are mentioned in the description... it's a constant load.

Also, those converters produce a "choppy" output, which luckily is filtered by switching power supplies of devices they recommend that product to be used with (chargers, shavers etc) but with a light, you may see flickering and the bulb may die prematurely.

 

The safest would be to use a regular (isolation) transformer. You can buy one that has a 230v primary or two 110v primaries (which you'd connect in series to get 230v) and 110v on the secondary side... and you'd simply use it in reverse, treating the secondary side as primary feeding 110v AC in it, so you'd get 230v on the other side.

 

Here's a bunch of them - filtered all that can do 50VA  or above (50w for lamps, less for other devices). Just have to pick one that has a  1:2 ratio between the sides, as in one side can be configured to 110v or 120v and the other side to 220-230v . Then you'd only need a plastic box, a mains plug and a cable and a wall socket to screw on the plastic box (or a power strip to cut the plug from it and connect the cable directly to the transformer)

https://www.amazon.com/gp/product/B017R17YQC/ref=s9_acsd_top_hd_bw_b5zITlz_c_x_w?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=merchandised-search-2&pf_rd_r=729269VXK8F2MZJ1DCD2&pf_rd_r=729269VXK8F2MZJ1DCD2&pf_rd_t=101&pf_rd_p=0f765e45-5d2c-4e0f-84b1-8455e483fe49&pf_rd_p=0f765e45-5d2c-4e0f-84b1-8455e483fe49&pf_rd_i=5486425011

 

Is this something what you are talking about? Could you possibly find me something like that on amazon as I dont know what mouser.com is? 

[mariushm]

No, that's a basic switching power supply (not actually a led "driver" as the label says). It takes in 110v or something like that, and produces 12v DC, up to 3A.  It doesn't produce 230v.

 

Before switching power supplies started to be used extensively, people used isolation transformers (some people call them power transformers). They're no longer used that much outside some areas (medical instruments and audio products) because they're much heavier and much bigger.

 

A transformer takes in some AC voltage and outputs another AC voltage, at some ratio.  For example, if the transformer is 1:2 , that means whatever comes in on one side is halved on the other side.  So for example, if you put 230v AC on one side, you get 115v AC on the other side... but there's no rule saying you can't just turn around the transformer and put in 110v AC and get 230v AC at the output.

 

mouser.com is an online store that sells electronic components (chips, components that make up electronic products etc, the stuff that's in things you buy from Amazon)

 

Anyway... it feels like you're too much of a noob when it comes to this and you're looking for the cheapest crap ... you won't get what you need at 20-30$.

 

 

[JokerProduction]

just get something like http://www.world-import.com/tc-500a-u-d.htm#sthash.wZfnGaHi.dpbs  (I've never used this company specifically)  They sell them in any wattage you need.  each bulb pulls around 7w so just pick a size that's appropriate for how many bulbs you plan on running. 

 

And to be clear that product I linked is essentially a transformer(not isolotaion) just in a nice pre wired safe enclosure.

 

Its really you only financially feasible option or just buy appropriate bulbs for the country you live in.

 

15 hours ago, mariushm said:

Before switching power supplies started to be used extensively, people used isolation transformers (some people call them power transformers). They're no longer used that much outside some areas (medical instruments and audio products) because they're much heavier and much bigger.

 

This is kind of OT but I think it bugs me as this is not completely correct.

 

An isolation transformer is a specific use of a power transformer.  Its used like you said for sensitive or critical equipment.  using a isolation transformer in the OP case would defiantly be a misapplication of a isolation transformer (and against electrical code in some countries)

 

Furthermore any transformer (*with the exception of a autotransformer) can be used as a isolation transformer there is no difference physically between the two.  The difference comes in how they are set up.  Normally you would ground the secondary side of the transformer to the same ground that the primary voltage is referenced from.  In a isolation transformer this connection does not exist and its own separate (electrically isolated) ground is ran to the device from the transformer.

 

Sure he could order all the parts separately from mouser and build something that will work but it will be much more expensive than just getting a device like what I linked above.