Old 05-01-2015, 10:39 AM #1
Marco Polo's Avatar
Class 2M Laser
 
Join Date: Nov 2012
Location: Ohio, USA
Posts: 614
Rep Power: 5432
Marco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond repute
Marco Polo Marco Polo is offline
Class 2M Laser
Marco Polo's Avatar
 
Join Date: Nov 2012
Location: Ohio, USA
Posts: 614
Rep Power: 5432
Marco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond repute
Default WTB: UK/AUS microwave transformer 240V 50Hz

Hi all,

I'm looking to buy one or two microwave transformers designed for the 240v/50Hz mains supply in the UK and Australia. I live in the US and will be running the MOT's on 120v/60Hz, with the idea that core saturation will be less of a problem due to UK/Euro/Aus units having to handle twice as many volt-seconds as their USA counterparts.

I understand that the secondary voltage will be less due to powering with lower supply voltage, but I wasn't planning on messing with high voltage anyway and will probably just remove the HV winding and replace it with a lower voltage/high current one.

I've found a few on the UK eBay and honestly, the price isn't that bad... about 26 ~= 40 dollars shipped international priority. The sellers on the Australian eBay won't ship to the US at all. Given the choice, I'd prefer to buy from another LPF member anyway, before going to eBay. If anyone has a 240v/50Hz MOT or two that they'd like to sell, please let me know.

Thanks,
MP


__________________

808nm : SkyLaser HL808 820mW
650nm : [C6] LPC-826 215mW - SkyLaser HL650 175mW - Radio Shack <5mW
638nm : Opnext HL63603TG 190mW - AtlasNova <5mW
632nm : Metrologic ML-868 <5mW - Uniphase 155ASL-1 HeNe 0.95mW
543nm : Melles-Griot 05-LGR-193-497 HeNe 2.4mW
532nm : SkyLaser HL532 w/ IR filter 200mW - Fasttech SD-301 120mW - Lazerer LZCS 105mW - Laser 301 custom mod 85mW - various Laser 301's
520nm : [C6] Osram PL520 110mW - SkyLaser HL520 50mW
450nm : [C6] Osram PL450 260mW - Lazerer LZCS 145mW - SkyLaser HL450 95mW - SkyLaser LP450 90mW
405nm : Laser 303 85mW - Laser 301 90mW

Radiant X4 LPM from Illumination Supply


CHEAP BATTERIES CAN KILL YOU - please read this thread to see the truth about UltraFire and other CRAP brands!
Marco Polo is offline   Reply With Quote


















Old 05-03-2015, 05:58 PM #2
Alaskan's Avatar
Super Moderator
 
Join Date: Jan 2014
Location: Great White Frozen North
Posts: 9,201
Rep Power: 1081900
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Alaskan Alaskan is offline
Super Moderator
Alaskan's Avatar
 
Join Date: Jan 2014
Location: Great White Frozen North
Posts: 9,201
Rep Power: 1081900
Alaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond reputeAlaskan has a reputation beyond repute
Default Re: WTB: UK/AUS microwave transformer 240V 50Hz

I used to build high power transmitters with high voltage transformers, would one of those work? If so, what would be the ideal constant current and voltage rating? Constant current meaning 100 percent duty cycle with transformers.
__________________

Attention new brothers of the collimated light!

Newbie advice: Please take the time to first make an introduction in the Welcome section before posting questions.


Divergence to spot size calc: - 1 mRad is about .057 degrees which expands to be very roughly ~10% the diameter of the moon or sun at their distances.

Divergence Calculator: pseudonomen137's JScript mRad Calculator - Measure your lasers beam dia. at 1 foot & then 20'.

Online calc. to determine spot intensity at different mRad's & powers: http://tinyurl.com/divergence-calculator

Laser Power Density Calculator: Laser Power Density Calculator - Ophir

Build a beam expander to reduce divergence: http://tinyurl.com/BeamExpander

University YAG Project The Professor's Homebuilt Lasers Site - YAG Lasers

YAG Power Calc. Laser Peak Power Calculator - Ophir

Angular Size Calculator; use with diode angle of radiation spec. for lens dia. at FL: Angular Size Calculator

RHD's Calc: http://lsrtools.1apps.com/RelativeBr...&useRaleigh=on

High Current Pulse Drivers: https://tinyurl.com/ya7whuk3
Alaskan is offline   Reply With Quote
Old 05-04-2015, 08:50 PM #3
vk2fro's Avatar
Class 3R Laser
 
Join Date: Nov 2009
Location: Sydney, Australia
Posts: 1,293
Rep Power: 209717
vk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond repute
vk2fro vk2fro is offline
Class 3R Laser
vk2fro's Avatar
 
Join Date: Nov 2009
Location: Sydney, Australia
Posts: 1,293
Rep Power: 209717
vk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond reputevk2fro has a reputation beyond repute
Default Re: WTB: UK/AUS microwave transformer 240V 50Hz

Damn if I had have seen this a bit earlier I could have scruffed the microwave I saw on the street earlier and salvaged the transformer. Most of the time over here its usually the fuse that pops and people just trash the microwave and buy a new one (they are cheap enough). 9 times out of ten the MOT is perfectly fine.

I'll keep an eye out. Postage is going to be painful though, MOTs are quite heavy (you probably already know this).

Provided you exercise proper safety procedures, they are also a tonne of fun to play with

I've killed a few in my time overloading them before I wised up and stuck a column heater in series as a ballast
__________________
Taipan Projector: 3.5-4 W B(445nm)1.5W, G(520nm)1W R(637nm)1W DT30 Still building!
All solid state PJ: 1W B(462)400mw G(520)200mw R(638) 400mw DT40W
Pointers: 1.0 watt "Z-Lase" - 520 nm diode by DTR attached to segelei zmax V5 Vaporizer
Gassers: ILT 5500ASL Multi Line AR Ion doing over 350 mW. 2590 hrs
Another ILT 5500ASL Single Line AR Ion 1500 hrs. Current mode 10.95 A 315mW Geez!
Yet Another ILT - 5500AWC - tunable Multi Line AR Ion inbound! - 100 hours. Almost Brand new.
Laser Graveyard:
Omnichrome 543 200MA Multi Line AR Ion doing 0 mW. Seller didn't pack properly. 32 hours on the clock too!

Last edited by vk2fro; 05-04-2015 at 08:56 PM. Reason: cant spell LOL
vk2fro is offline   Reply With Quote
Old 09-08-2016, 08:47 PM #4
Marco Polo's Avatar
Class 2M Laser
 
Join Date: Nov 2012
Location: Ohio, USA
Posts: 614
Rep Power: 5432
Marco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond repute
Marco Polo Marco Polo is offline
Class 2M Laser
Marco Polo's Avatar
 
Join Date: Nov 2012
Location: Ohio, USA
Posts: 614
Rep Power: 5432
Marco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond reputeMarco Polo has a reputation beyond repute
Default Re: WTB: UK/AUS microwave transformer 240V 50Hz

Quote:
Originally Posted by vk2fro View Post
Damn if I had have seen this a bit earlier I could have scruffed the microwave I saw on the street earlier and salvaged the transformer. Most of the time over here its usually the fuse that pops and people just trash the microwave and buy a new one (they are cheap enough). 9 times out of ten the MOT is perfectly fine.

I'll keep an eye out. Postage is going to be painful though, MOTs are quite heavy (you probably already know this).

Provided you exercise proper safety procedures, they are also a tonne of fun to play with

I've killed a few in my time overloading them before I wised up and stuck a column heater in series as a ballast
I finally got a MOT from the UK. 45 dollars shipped, doesn't seem too bad. Feasible to get another one if I kill this one or want to do the anti-phase inputs and split-phase secondary thing for twice the volts. The seller didn't pack it worth a damn though, no padding whatsoever. a bit disappointing. The windings appear to be fine but one corner of the core got bent/deformed from hitting something hard. I used a vise to flatten it out a bit so it looks ok.

It's 230V 50Hz, with a variac I have 144V 60Hz, so low idle current. It can arc a bit but not a whole lot. The primary wire is noticeably thinner than 120V primaries, is aluminum, and gets hot quickly when you arc it. I guess that makes sense, a microwave that draws 1200W only needs 5A. Maybe twice that while being misused. It looks too small to have come out of anything much bigger than 1000W though.

I can sometimes trip the 20A breaker if I arc the old Basler Electric MOT long enough, with enough volts and some fan cooling. The UK MOT would be in flames long before anything trips (even at 144V) so I guess that qualifies as a fire hazard.

I would need another one to wire antiphase if I wanted ok arcs but for now I don't have the time. This one could probably make an OK ballast but for now it's mostly just a doorstop, or sometimes a paperweight. I note the shunts are a lot smaller than on a 120V MOT, so maybe the UK cores are smaller because they have enough turns per volt despite 240V 50Hz.

Well, whatever. At least it's pretty clear that 120V MOTS (the older ones at least, those made in the USA) can arc as well as a 240V unit, without needing a ballast necessarily. They are "120V" but start to saturate by 90V and handle ~105V if duty cycle is short. It's pointless to over that, although tbh I guess it's a bit pointless to do this kind of thing in the first place. But still something to do if you're bored or want to electrocute something.
__________________

808nm : SkyLaser HL808 820mW
650nm : [C6] LPC-826 215mW - SkyLaser HL650 175mW - Radio Shack <5mW
638nm : Opnext HL63603TG 190mW - AtlasNova <5mW
632nm : Metrologic ML-868 <5mW - Uniphase 155ASL-1 HeNe 0.95mW
543nm : Melles-Griot 05-LGR-193-497 HeNe 2.4mW
532nm : SkyLaser HL532 w/ IR filter 200mW - Fasttech SD-301 120mW - Lazerer LZCS 105mW - Laser 301 custom mod 85mW - various Laser 301's
520nm : [C6] Osram PL520 110mW - SkyLaser HL520 50mW
450nm : [C6] Osram PL450 260mW - Lazerer LZCS 145mW - SkyLaser HL450 95mW - SkyLaser LP450 90mW
405nm : Laser 303 85mW - Laser 301 90mW

Radiant X4 LPM from Illumination Supply


CHEAP BATTERIES CAN KILL YOU - please read this thread to see the truth about UltraFire and other CRAP brands!

Last edited by Marco Polo; 09-08-2016 at 08:50 PM.
Marco Polo is offline   Reply With Quote
Old 09-12-2016, 06:32 PM #5
Class 1M Laser
 
Join Date: Mar 2008
Location: NJ
Posts: 213
Rep Power: 406
kaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond repute
kaunak kaunak is offline
Class 1M Laser
 
Join Date: Mar 2008
Location: NJ
Posts: 213
Rep Power: 406
kaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond reputekaunak has a reputation beyond repute
Default Re: WTB: UK/AUS microwave transformer 240V 50Hz

I bought a couple 120V MOTS on eBay in the last few years, and the 120V versions were only about $25USD with shipping. I guess the 240V UK versions are slightly more than that on average. I've done a good amount of experimenting with them over the years(120V MOTS) and figured out the best way to get nice arcs from them without burning the windings out too quickly, is to short out the secondary on one 120V MOT and use the secondary-shorted MOT as the ballast for the other 120V MOT which will have a stable 1000W ~500mA output on the secondary. That's about the max you can get from any MOT secondary unless you remove the shunts. Even with the arcing transformer shorted, the primary current is 'only' about 20-21A on the primary and usually won't trip a 15 or 20A breaker in any short amount of time. I've found this to work very well and I can pull a stable arc from the second MOT for about 5 minutes straight without any issues. Of course the MOT will get pretty hot, but it will not start smoking the windings at all and there will be no damage to either transformer. MOTs are tough transformers no doubt. I can't say this would work as well with any two MOTs because of manufacturing differences, but the ones I used were pretty standard and weighed about 10lb each.

Last edited by kaunak; 09-12-2016 at 07:06 PM.
kaunak is offline   Reply With Quote
Reply





Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

























Privacy Policy | Advertising Disclaimer | Terms of Use


 


All times are GMT. The time now is 07:20 AM.


Powered by: vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO
Privacy Policy | Advertising Disclaimer | Terms of Use
Copyright (C) 2017 Laser Pointer Forums, LLC