How to modify Roomba 560 Power Supply for 220V/240V outlet ?

[eddise]

Heyeah,

I just brought Roomba 560, the Charger that comes-with is 17062 (110V). My country power outlet is 220v/240v. I found few urls documented the modding of its Power Supply Unit, PSU (17062) to work on 220v/240v. I seems to be almost ready but need to confirm on a FUSE !

Summarising, to convert the PSU for 220/240v, 3 or 2 parts needs to be replaced/removed:
1. A capacitor C1, replace to 47uF/400V (from 47uF,200V org)
2. A Varistor RV1, replace to 14D361K or 14D391K (from 10D271K rated max VAC 175v). Remove RV1 is alright too
? 3. A Fuse F1, replace to 1.6A 250V (from T3.15A 125v)

For more backgrounds, here are some documentations (leave the fuse intact) :

http://www.schneordesign.com/Avi/irobot/roomba_mod1.htm
viewtopic.php?f=4&t=294&start=180
viewtopic.php?f=4&t=294&start=120
viewtopic.php?f=4&t=294&start=140

While some recommends the FUSE to be replaced:
http://abecemod.blogspot.com/2008/02/ir ... 0240v.html

As of now, I had:
- replaced the Capacitor C1 to a 47uF,400V, electrolytic;
- Had replaced the Varistor with a 14KD391 (that is, 391).
- Alas... I had brought the wrong kind of fuse.... I can still get hold of the right fuse, but, it is the outcome I am concern.

Go or NG for the fuse ? I am con-FUSE-d !

Any advice from you will be appreciated.

Thanks in advance

[Gordon]

modding of its Power Supply Unit, PSU (17062) to work on 220v/240v. I seems to be almost ready but need to confirm on a FUSE ! ...
? 3. A Fuse F1, replace to 1.6A 250V (from T3.15A 125v)

If I were doing the work on my own PSU, I would leave the T3.15A untouched. See this post (a post in one of your referent threads): viewtopic.php?p=46555#p46555
read the subsequent success story, and follow the link to rj5555's post. rj5555 has EE credentials.

BTW, installing a "1.6A 250V" fuse would be a gross mistake; since it lacks the time-delay feature. The "T" prefixing 3.15A stands for time delay.

BTW2: You may be overlooking a diode that might have to be upgraded. Its PCB mark is "D11". Look for it at the low-voltage end of the PCB. You should do an "Advanced search" for Author = red_sword_fish, then read his posts on this matter.

Never mind, I searched for you. Start here: viewtopic.php?p=67069#p67069
Use care to note which PSU is being discussed, because Roomba PSUs posts are mixed with Scooba-PSU posts. Use PSU_PCA pictures to match with your 560's PSU_PCA, so you have assurance the information applies to your unit.

[eddise]

Hi Gordon,

Thanks for the respond, appreciate that. Hopefully you could further advice few of my doubts.

As of now, my understanding is :
- Replace C1 to 47uF/400V (done) ;
- use the orginal Time Delay fuse T3.15,125V (done) ;
- (BTW, Is my varistor fine 391KD14 ok? )
?- And, there is another Diode, D11 to replace -> target is 1N4007 (any in the 1N4001 to 1N4007 family). Does this replacing this diode has anything to do with a regulator 78L05?

I have query on this diode is because, Having read viewtopic.php?p=67069#p67069 ,saw its pics. I discovered , my PSU does not use the 78L05 regulator.


My Roomba PSU label (forget to take pics of the cover):
Model Number: 17062
Input: 120VAC 60Hz 0.68A
Input Power: 33W
Iuput: 22.5VDC 1.25A

Here are the Pics of my Roomba 560 PCB :
Note1: non-existence of 78L05 regulator
Note2: On PCBs with 78L05, around the 78L05 there are 2 transitors-looking-components. But for my pics, there is only 1(see details).

(Below) The PCB:


(Below) The back:


(Below) The location 'where 78L05 is suppose to be' :




(Below) Other pics around the board :








Thanks for everything.

[Gordon]

Hi Gordon, Thanks for the respond, appreciate that. Hopefully you could further advice few of my doubts.

Yes, and thank you for a great set of PSU pix.

...- (BTW, Is my varistor fine 391KD14 ok? )?-

As I recall, the "391" equates to an onset voltage of 390V, and if so, you want to compare the peak mains voltage to 390V, making sure that Vpk is less than Vonset. Vpk = SQroot2 * 240V = 1.41 * 240 = 339V, so you have 390 - 339 = 51V of margin voltage to accommodate brief surges and voltage spikes which normally occur on the mains.

And, there is another Diode, D11 to replace -> target is 1N4007 (any in the 1N4001 to 1N4007 family). Does this replacing this diode has anything to do with a regulator 78L05?

I have no personal experience with it, but, as you read, red_sword_fish has confirmed that relationship. But, some members have reported no fault with their PSU by not changing D11.

I have query on this diode is because, Having read viewtopic.php?p=67069#p67069 ,saw its pics. I discovered , my PSU does not use the 78L05 regulator. ...

Actually it does use the 78L05. Look at this blow-up from one of your pix:

I can't see a board marker (Uxx) for that regulator, but its in the same relative position to C11 & C18 as on r_s_f's PCA. Notice the marked dates on your PCB and on r_s_f's; his is three years older, and some components have been shifted (careful inspection would be needed to detect whether some have been deleted and or replaced by new devices -- slight circuit changes may have been done) over those years. Upgrading D11 (to 1N400x) will not harm anything, and right now the work can easily be done.

[eddise]

Hi Gordon,

Thanks for your helping hand again

With all your confirmation, I am confident to go ahead with these changes :
1. Change capacitor C1 (previously done) ;
2. Change Varistor RV1 (previously done) ;
3. Change D11 to 1N4007 (just done) ;
4. Let the original time delay fuse (T3.15, 125V) remains.

However, I couldn't get locate my finer soldering flux and had to do with a bigger diameter one. Wasn't too careful while working on D11.... the solder 'spreads' - to 'touch' R21 (as seen on the reverse of the PCB).

I was panic enough to refer back to all those pics I had taken - not too detail. After zooming in and out I can only bank on R21is linked with D11 since the PCB route seems to be .....

So I went ahead to fire it up ..... Outcome was seemingly sucessful (see pics) --> the voltage was 22.4 (Roomba PSU rating was 22.5VDC). I hear hissing(or hizzing) sound from the PSU (this was also encounter by some other modder).

I share let the PSU runs without roomba for half a day or so (before feeding its current to Roomba).

I will come back to update again.

Thanks Mike

[eddise]

... I had already use the charger for a few charging cycles, it is doing fine and roomba is alright too.

[bcarpenter]

The Roomba's power supply is just an AC to DC transformer. What's wrong with wandering into Dick Smith & buying a transformer with the same output voltage, power & plug size?

[Gordon]

The Roomba's power supply is just an AC to DC transformer. What's wrong with wandering into Dick Smith & buying a transformer with the same output voltage, power & plug size?

Answer:

1) iRobot's charging PSUs are not "just an AC to DC transformer" type of PSU.
2) Not all operating characteristics are listed on iRobot's PSUs; hence, you would not know how to specify "just an AC to DC transformer" PSU to the clerk.
3) Likely, you would pay more for an equivalent "just an AC to DC transformer" type PSU that would perform same as an iRobot PSU. It would also be heavier by several factors, and waste more energy while being used.

Do some reading at this page (its about a Scooba PSU, but transformation of mains power to direct current charging power matches Roomba's): http://mysite.verizon.net/gsplews/26DCpwrSup.htm

[550bot]

hi,
I'm new and just posted in reference to an image on this post rather than replying here..

sorry for being off topic.. but i need help!

question.. in the image showing the varistor RV1.. what is the brown component (cylinder shaped) ???

a power surge burned the varistor and i figured i may need to replace this brown one as well.

any help is greatly appreciated.
thanks!

nick

edit. i see that links in this post have info on what the components are. sorry for asking that info.
where can i get the time delay fuse?
i found the varistor at http://www.galco.com
no luck on the time delay fuse.. i hope its not fried as well.

[550bot]

i just checked out the link in the comment above mine and also looked at my PSU..
component in question is marked F1, hence i imagine its what Gordon mentions in his webpage

"Line Fuse: In the SPSU which was examined, its F1 case marking is: "CQ MET | T3.15A 250V". This is a 3.15A time-delay fuse. "

i guess now i just need to find these.. or at least the varistor for sure.

any way i can test the line fuse mentioned above?

[Jubo]

you can do a con check on the fuse to determine if it is opened.

[550bot]

thanks for your reply.
i tested and its open. i wasn't sure if this is the normal state.
via the link on this page, and then links on Gordon's page (thanks! i ended up on a site recommending to search for part on yet another site.

I ordered both of them. they were less than .50 cents each so i ordered a few.
after reviewing the spec sheets, i think i got the right ones.
I really appreciate this post. it (hopefully) will have the roomba operational in a few days.

http://www.mouser.com/Search/ProductDet ... 7413150410

http://www.mouser.com/Search/ProductDet ... V175LA10AP

[Sc0rPs]

I recently had to ship one overseas that needed to be converted as well, but instead I got a quality transformer with it's own fuse designed for permanent use. It only cost $30.

[Gordon]

...http://www.mouser.com/Search/ProductDet ... V175LA10AP

Since you have ordered parts from (USA) Mouser, I presume you live in the US, and have 120VAC outlets in your house.

The point of this reply is: That 175-volts (onset to break-down) varistor may begin to conduct (shunt current to the power-return rail) under permitted high-line voltage for nominal 120VAC mains. The shunt-current (handled by the varistor) will then add to the current drawn by the SMPS.

Here's the basis for that "may begin to conduct" claim:

{USA domestic mains are} Standardized at 120 V. Electricity suppliers aim to keep most customers supplied between 114 and 126 V most of the time. http://en.wikipedia.org/wiki/Mains_elec ... by_country

That is: 120VAC+/-5%. When mains voltage is highest (126VAC, rms), it impresses root2*126V = 1.414*126V = 178 peak-volts (for a couple milliseconds each half cycle) across the varistor, so, depending on the tolerance of the varistor's 175-V_BDonset parameter, the varistor may, or may not start to conduct shunt current.

I think the potential fuse-blowing concern is limited to occurring at the moment you apply mains power to the SMPS, rather than during a charging session following a successful power-up.

I did not back-track to check on whether that particular varistor, V175LA10AP, was used by iRobot, but if your PSU ever blows a ~ 3A fuse, and if you still insist on using a varistor (vs. leaving it out of circuit) you might consider buying / installing the next higher voltage varistor.

[eddise]

The Roomba's power supply is just an AC to DC transformer. What's wrong with wandering into Dick Smith & buying a transformer with the same output voltage, power & plug size?

This is really on how individual wish to approach the problem.

1. Power efficiency and form factor is the advantage, I guess ;
2. There are times Roomba scheduler charge un-attended (no-one at home), inappropriate/unreliable overheated transformer pose potential fire risk ;
3. Plus ... this Roomba PSU is super light weight, I would love to see it working ;
4. Leaving the Roomba PSU lying on the shelf is the last thing I would do.

On the other hand, in order to find a compatible transfomer, I also need to spend effort and take higher risk trying it out on the robot.

[550bot]

hi, I just stopped by to thank contributors of this post. sorry I am quite off topic of the original post.

The installed components seem to be working fine and the roomba is charging at this moment for a cleanup tonight.

Gordon, I think you are directing the above comment towards me and stating that I should be using a varistor that has a higher voltage rating, as some peak voltage may meet or exceed the rating of the varistor. I guess if it blows then I'll bother to order a higher voltage. from what i read that night, it seemed it was a 175V to being with.

Eddise, thanks for this post, as it's the best thing that came up from my google search in order to identify and get information on these parts, along with Gordon's invaluable contribution via his website... and another site which mentioned mouser as a source of procurring the parts.

Time will tell,.. I ordered 4 parts of the varistor and the fuse, so if it blows I will order a higher rating and temporary install another varistor to get by until it arrives.

thanks again to you all for sharing and disucssion.
nick

EDIT: ps. the burned fuse was measuring open with the ohm meter.. the new ones are closed. just an FYI if anyone stumbles across this post and needs to know.