on May 11, 2015
"Simran SMF-200 Deluxe 200 Watts Step Down Voltage Converter for International Travel to AC 220V/240V Countries". I bought this product for a trip to Spain, needed to run my laptops and to recharge phone, camera, laptop batteries, etc.
Note that the power supply for my laptop is rated as having a 120-240V input. Many power supply "bricks" are thus rated, in principle letting them plug directly into a 240 volt supply (Spain). Thus in theory, I could have plugged my laptop directly into the Spanish outlets. However, reality does not always respect theory, so despite its nominal 120-240V input, I had concerns about my power supply overheating or burning out if I plugged directly into the Spanish receptacles. So instead, I plugged the Simran SMF-200 into the 240V wall, then my laptop power supply into the SMF-200, knowing that if anything blew out, it would be the SMF-200 converter, but my laptop and its adapter would be safe. Some of my other devices, such as my camera battery charger, have only a 120V input rating, so the stepdown converter was mandatory.
To use this device, I plugged it into the Spanish wall receptacles. I then plugged my PC power supply (2-prong American) into the outlet on the SMF-200. To use or charge several devices at once, I first plugged a portable multi-outlet power strip into the SMF-200. My peak usage was to simultaneously run my main laptop, charge the battery on my secondary laptop, charge a camera battery, and charge a smartphone.
For my needs, this product worked perfectly. If your needs are the same, then this review is a "recommend".
Reviews on Amazon are mixed, only 52% 5-star, and 20% 1 & 2-star. The common negative thread seems to be the device not working after a while, smoking or fizzling out. It seems like many (but not all) complaints came after using hair dryers or other "appliances". I think these comments reflect the limitations of this device and inadequacies of the product description. It is good for certain uses, not good for others. Buy it and use it for the wrong purpose, and it will break and seem like a worthless purchase.
Here is what I noticed. When plugged in but not charging or running anything, the SMF-200 was slightly warm (as expected, like any transformer or power brick). When running my laptop, it was even warmer, more so than expected for a normal power brick running off of 120V, but consistent with expectations for a voltage down-converter. However, it was not unusually or dangerously hot, and I never sensed that it was overheating. However, I would worry that if trying to run a hair dryer or some other non-digital crude electrical device, that it would get excessively hot.
This device cost $13.65 from Amazon - cheap. That does not imply that it is cheaply made, just that it is a minimally engineered item made with a minimum of inexpensive parts. It is solid and heavy, the outer case sturdy and well fit. Inside, I imagine it is just another power brick, a simple transformer with a 240V input and a 120V output. Among electrical devices, it is about as low tech, basic, and inexpensive as anything there is. This is not a pejorative "you get what you pay for". You get exactly what you pay for as long as you understand what you paid for, a bare bones no frills transformer that probably delivers its nominal specs but with no margin or safety factor.
Two things to keep in mind: (1) Hair dryers and other devices with crude electric motors create power spikes that might overwhelm the nominal specs of the SMF-200. (2) A transformer generates waste heat, and as you put more load on it, it gets hotter. Cheap transformers generate more heat (efficient low loss transformers are more expensive). Furthermore, if the device is not designed to dissipate waste heat, it can overheat, damaging insulation or other coatings, then smoking then shorting out dead, even before reaching its nominal power rating. That would seem to be the case with the SMF-200. Running a hair dryer for 5 minutes on this thing will probably cook it, as reported in the many negative reviews.
This device is not meant to run hair dryers and other "appliances", nothing with a heating element or an AC motor, nothing that exceeds the power rating of the SMF-200. I would suggest that you keep net power draw to no more than 80% of rated capacity (200 x 0.80 = 160 watts). Also, when I used it, I plugged in then promptly unplugged it when not in use. I had it plugged in for many hours at a time, but never just for standby or because I had forgotten it (which can burn out cheaply made transformers or bricks).
One Amazon review mentioned dismantling the item to find that "ground" on the three-prong receptacle was not attached to anything. Spanish receptacles seem to have only two prongs, so it is not surprising that the third prong slot is a "dead end". However, it does serve the purpose that if the plug on your device has a third prong, then you can at least plug it in and get power (plugging a three-prong male plug into a two prong female receptacle just isn't possible). However, if your device was designed with a third prong ground, there was probably an important safety reason for doing so, so electric shock safety is another factor for not using higher power crude electrical devices with the SMF-200 or anything that has a three prong plug.
For me, this product worked properly, without fault or concern, for the purposes I used it for - running a high performance laptop and charging other items. It got me through my trip worry free, my devices and my work sessions unhampered due to lack of electricity. Furthermore, I had confidence that my devices and their primary power supplies were protected. If your needs are the same, I think this product will work equally well. If you need to use electrical rather than electronic devices (hair dryer for instance) or else high power electronic devices such as a desktop PC, then you are taxing the limits of this device. If you overload the SMF-200 by approaching its nominal power rating or by using crude electrical appliances, either your devices will "brown out" or else the SMF-200 will overheat then burn out.
If you need to use electrical or higher power devices, you should probably heed the advice of the negative reviewers and look for another more expensive item. Its performance for my needs was 5-star. The marginal product description and documentation (and lack of a clear explanation of what it can and cannot do) do not invalidate what it can do, but it all creates unnecessary hardship for those who buy the SMF-200 with false expectations, so that knocks it down to 3-star. They could have added a circuit breaker or thermal overload switch to protect the device and thereby the investment of those who buy it, but in the end, it is just a cheap device that works well within its limited range but will disappoint many people who have other needs. If you are reasonable in your usage, I think it averages out to a 4-star rating.