The 200V rating is fine for 110V mains, but will surely blow if used at 220V mains. The whole power supply circuit it’s already designed for universal 110V-230V usage, except for the input capacitor after the rectifying diodes, which is a 47uF 200V electrolytic. The Roomba power supply is a standard switching power supply, based on the TopSwitch Top245Y chip.
That need to be modified in different ways:ġ) Roomba power supply first revision (model number 10556)Ģ) Roomba power supply second revision: it differs from the previous because it has a Zinc Oxide Varistor named VR1 or RV1 (see pictures below)ģ) Scooba power supply (model number 13143)ġ) Mod for Roomba power supply first revision (model number 10556) If you find a power supply with more than 2Amp it would be perfectly fine, considering that the recharging circuits are inside the Roomba/Scooba, not in the power supply, nor in the Roomba base. Usually you can find this kind of power supply as replacement parts for laptop, with prices ranging from 40 to over 100 Euros. If you don’t want or if you feel that you don’t have enough experience & knowledge for this kind of modifications, it is better to use a good 220V AC to 22V DC 2Amp minimum power supply, rather than a 220V -> 110V converter.
Maybe these are the reasons why it is expressely specified in the Roomba manual not to use external converters.īefore continuing in reading the rest of the article, please read carefully the following notes:ġ) The modification of the Roomba fast charger will certainly void your warrantyĢ) Once you open the fast charger casing, you are exposed to lethal high voltagesģ) Any mistake in the modification can lead to components exploding & causing fireĤ) If you are not an experienced electronics technician, don’t even try to open the charger caseĥ) Electrolytic capacitors have polarity, are mechanically sensitive and may easily blowĦ) If you want to proceed with the mod you will take the responsibility for any problem that could arise This condition (60Volts AC mains) would never happen in real life, but with an external 220V -> 110V converter it could be possible. It seems there is a bug at the design of the power supply and at undervoltage conditions, the TOP245 can behave in a wrong way. The other problem is that if you fed the original Roomba fast charger with a voltage below 80V AC you can have an output voltage over the rated 22V DC.įor exapmle feeding the fast charger with 60Volts AC, it’s output would be at 40V DC and any connected Roomba/Scooba will be destroyed.Īccording to the TOP245 (TOP246 for Scooba) datasheet, the 1Mohm and 1.3Mohm resistors R1 and R2 (on the power supply board) at the Line Sense pin of the TOP245/TOP246 should shut it down if the input voltage falls below 100 VDC at the filter capacitor, but this does not happen. In this case the converter would certainly blow the Roomba/Scooba power supply (please note that the peak voltage cannot be measured with a standard digital multimeter, but only with an oscilloscope). If your converter outputs 110V RMS, this doesn’t mean that the peak voltage will be less than the maximum allowed (155 Volts) of the original power supply.įor example, with a Remington 220V -> 110V electronic converter, which outputs 110Volts RMS, the peak output voltage is more than 200V (without any load).
The first problem you encounter if you use an external 220V -> 110V converter to power the original Roomba/Scooba power supply is the output voltage quality (the 50/60 Hz rating is not critical). Let’s understand why it’s not possible to use external converters! It’s not possible to use an external 220V -> 110V converter since it is explicitly prohibited in the iRobot documentation, it wont work and it may destroy the power supply (and eventually the Roomba/Scooba internal recharging circuits).
If have bought or want to buy a iRobot Roomba Discovery series (second generation: Discovery, Scheduler, etc) or Scooba 5800/5900 in the US and want to use it in Europe, you need to modify the included power supply that works only with 110 Volts mains.