I moved from the US to Singapore about 10 years ago. I had my Monsoon PlanarMedia 9 system shipped with our household items and I'm just now digging it out (yeah, it takes me a while to unpack).
My PM-9 is rated for 120 VAC 60Hz but here in Singapore, the supply is 230VAC at 50Hz. I assume that the frequency difference in this particular application won't be critical (is that correct?). I'd like to swap out the onboard transformer for one that will work with the local supply. I'm not a complete novice, but I haven't done much electronics DIY since moving to Singapore, so I suppose it would be appropriate to respond as though I am a novice.
The markings on the transformer are:
HK76H-129
TTI1201C014
BUILT IN THERMAL FUSE
0233
And on the side:
DAR PLUS A
I can't find any info on this part, and therefore, I don't know what the output should be. I also don't have an external step-down transformer in order to be able to power up the unit and test the output.
Does anybody know if I can simply swap out the transformer in this application? Any idea of the transformer output or how I could measure it?
(I have a few pics of the transformer if that will help--just let me know if it's necessary to post them)
My PM-9 is rated for 120 VAC 60Hz but here in Singapore, the supply is 230VAC at 50Hz. I assume that the frequency difference in this particular application won't be critical (is that correct?). I'd like to swap out the onboard transformer for one that will work with the local supply. I'm not a complete novice, but I haven't done much electronics DIY since moving to Singapore, so I suppose it would be appropriate to respond as though I am a novice.
The markings on the transformer are:
HK76H-129
TTI1201C014
BUILT IN THERMAL FUSE
0233
And on the side:
DAR PLUS A
I can't find any info on this part, and therefore, I don't know what the output should be. I also don't have an external step-down transformer in order to be able to power up the unit and test the output.
Does anybody know if I can simply swap out the transformer in this application? Any idea of the transformer output or how I could measure it?
(I have a few pics of the transformer if that will help--just let me know if it's necessary to post them)
It seems to be an AC power adapter rather than a transformer.
Monsoon Planar Media 9 Audio System .Speaker Replacement
Monsoon Planar Media 9 Audio System .Speaker Replacement
I suppose that my questions are more general in nature. Sure, I happen to have the planar speakers, and that's why I posted in this section, but I suppose this question could be asked of any brand of speaker subwoofer. Not sure if I posted in the best place to have the most eyes see this.
Did you not take a look at the link I posted? Dave has quite clearly stated the output voltage of the brick.
It would be a pretty simple matter to either source a brick of the same voltage.
It would be a pretty simple matter to either source a brick of the same voltage.
Am I correct that a brick is an external device that is inline with the AC line, similar to a laptop? If so, I don't have a brick.
I have a typical US grounded blade plug (2 flat blades, one ground prong) that runs through a line directly to and through the back of the subwoofer, to a main on/off switch, then to the transformer in the pics.
I have a typical US grounded blade plug (2 flat blades, one ground prong) that runs through a line directly to and through the back of the subwoofer, to a main on/off switch, then to the transformer in the pics.
That's a change then. Monsoon's page states that the power adapter is external.
The voltage should not have changed, so the 15VAC advice should still be gold. There are two wires on either side, so it's definitely just one winding.
The voltage should not have changed, so the 15VAC advice should still be gold. There are two wires on either side, so it's definitely just one winding.
Ok, cool.
Just to confirm then, I'll need a mains transformer for 50Hz that steps down from my supply voltage of 230VAC to 15VAC correct? I assume the rectifier will have no problem with a 50Hz input instead of the original 60Hz input. Is that correct?
I've attached some more pics in case anybody needs these in a future search. In the thread that Sangram linked, handrew shared a schematic in post #86. However, the schematic is for the PM14 whereas I have the PM9. Similar but some differences if you compare the schematic to my pics.
Just to confirm then, I'll need a mains transformer for 50Hz that steps down from my supply voltage of 230VAC to 15VAC correct? I assume the rectifier will have no problem with a 50Hz input instead of the original 60Hz input. Is that correct?
I've attached some more pics in case anybody needs these in a future search. In the thread that Sangram linked, handrew shared a schematic in post #86. However, the schematic is for the PM14 whereas I have the PM9. Similar but some differences if you compare the schematic to my pics.
Attachments
Ok, great. Where is a good place to start searching for one? Are there new parts for sale on this site?
Easiest might be to get a 220 to 110v transformer/autoformer.
You will not likely find a Monsoon part.
PM14 is not likely the same as PM9.
dave
You will not likely find a Monsoon part.
PM14 is not likely the same as PM9.
dave
What Planet10 said. Given the low power level it should be not to expensive. And unless .sg has radically changed in the last decade, there'll be plenty of places with them (Mustafa's comes to mind)
I'm hoping to not have another external component, hence the desire to change out the internal PT. However, I'm not sure if it's possible with currently available parts and with this specific circuit. It doesn't bother me to replace parts with non-OEM--again, if possible. I'm just not sure of all the ramification of swapping the PT.
Would something like this work?
https://www.newark.com/block/st-100-23-12/transformer-iso-12vac-100va/dp/55X2492
Would something like this work?
https://www.newark.com/block/st-100-23-12/transformer-iso-12vac-100va/dp/55X2492
oh, and thoglette, Mustafa's is a good place but not too far away is Sim Lim Tower and Sim Lim Square. They are the ultimate DIYer's paradise for electronics. Shops packed wall to wall, floor to ceiling with goodies
Probably: it's 100VA which is the magic number, according to the label on the back of my PM-9
I can't honestly remember what the secondary voltage was but if you feed a a dozen volts AV into the primary & measure the secondary, then you'll be able to confirm what the correct voltage should be.
I found an old wall-wart style voltage converter that I used to feed 120V into the sub's internal power transformer. Measured 12V across the secondary winding. I guess it's a 10:1 ratio for anybody who may need this info in the future.
I also measured the mains supply voltage and it was 240V, although Singapore is (I believe) listed as a 230V grid. I'd think that I should be able to find a relatively cheap 240V-to-12V power transformer rated for 50Hz. But then again, I haven't really started searching, apart from the link that I provided in the earlier post. I hope it doesn't turn into a needle-in-the-haystack search, lol.
Anybody with experience want to opine whether transformers rated at 50Hz and 220V, 230V and 240V at the primary would all work in this particular case?
I also measured the mains supply voltage and it was 240V, although Singapore is (I believe) listed as a 230V grid. I'd think that I should be able to find a relatively cheap 240V-to-12V power transformer rated for 50Hz. But then again, I haven't really started searching, apart from the link that I provided in the earlier post. I hope it doesn't turn into a needle-in-the-haystack search, lol.
Anybody with experience want to opine whether transformers rated at 50Hz and 220V, 230V and 240V at the primary would all work in this particular case?
Attachments
I finally had some time to look around the local shops for a power transformer. Plenty to be had in the USD20-25 range.
However, the 100VA PTs that I came across are quite a bit larger than the original. This leads me to believe that:
1) the original Monsoon PT is a high-density special PT and therefore can pack 100VA capacity in a much smaller and lighter form (I highly doubt this based on the price point of the system)
or
2) the Monsoon PT is not 100VA, even though the subwoofer nameplate says 100W (see earlier picture)
I assume that if I undersize the replacement PT, then it could easily overheat or worse. Is there some way that I could determine the VA rating of the original PT so that I can confidently fit a properly spec'd replacement? Also, the original PT has a thermal fuse while most of the PTs that I saw at the shops did not have one. How critical would this be?
However, the 100VA PTs that I came across are quite a bit larger than the original. This leads me to believe that:
1) the original Monsoon PT is a high-density special PT and therefore can pack 100VA capacity in a much smaller and lighter form (I highly doubt this based on the price point of the system)
or
2) the Monsoon PT is not 100VA, even though the subwoofer nameplate says 100W (see earlier picture)
I assume that if I undersize the replacement PT, then it could easily overheat or worse. Is there some way that I could determine the VA rating of the original PT so that I can confidently fit a properly spec'd replacement? Also, the original PT has a thermal fuse while most of the PTs that I saw at the shops did not have one. How critical would this be?