- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
If I took 2 - 60 watt electronic low voltage transformers (120V- 12V) and hooked them up in parallel, what would happen? Would I get 120 watts out of it???
Parallel 60 watt electronic low voltage trany
- Thread starter Dennis Alwon
- Start date
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gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
141211-1052 EST
Dennis Alwon:
What is a "60 watt electronic low voltage trany"?
Is this an AC or DC output? If AC how close to a sine wave is the output?
If AC is the waveform synchronized to the input AC waveform?
If synchronized that also implies exactly the same frequency, but not necessarily no phase shift.
If AC output my guess is that paralleling can be a major problem.
.
Dennis Alwon:
What is a "60 watt electronic low voltage trany"?
Is this an AC or DC output? If AC how close to a sine wave is the output?
If AC is the waveform synchronized to the input AC waveform?
If synchronized that also implies exactly the same frequency, but not necessarily no phase shift.
If AC output my guess is that paralleling can be a major problem.
.
After energising their primaries, connect one lead of reach secondary togather. Connect oth
er two leads to true RMS voltmeter. If zero, ok. Otherwise change connections and see if zero reading obtains
If you still do not, simply give up your attempt to parallel.
er two leads to true RMS voltmeter. If zero, ok. Otherwise change connections and see if zero reading obtains
If you still do not, simply give up your attempt to parallel.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
If these 'transformers' are actually electronic switching power supplies, then unless they have been designed for parallel operation, they will likely let out their magic smoke when operated in parallel.
You might be able to get around this by using 'or-ing' diodes to parallel them...but might have better results simply splitting your loads so that each transformer has a separate load.
-Jon
You might be able to get around this by using 'or-ing' diodes to parallel them...but might have better results simply splitting your loads so that each transformer has a separate load.
-Jon
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
If the output is AC I don't think 'or-ing' diodes would be a solution.
In which case I don't think it will work.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I thought this would be the case. I also thought about splitting the load but it would mean having to rewire the fixture. I will probably just get a 100 watt trany.
The reason I asked is because I have about 60 of the 60 watt tranies-- I may try it just out of curiosity sake since I paid nothing for these tranies.
I think new they probably cost all of $5-$10...
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
No real smoke but the tranies are now toast. 
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I only need a 75 watt trany-- that is what was in the fixture so I got one on the ebay for 7.95 -- no shipping cost
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Yes, but I couldn't resist.............No- you said I don't think...... not the same as it wont work...
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
If they were truly identical AC magnetic transformers (identical turn count), then paralleling should be fine as long as correctly phased. But it may be more likely that they used phase controlled SCRs to provide a non sine wave 60V RMS AC.No real smoke but the tranies are now toast.
In that case small component value differences could cause serious problems since the output waveforms would not be identical and an output circuit not expecting to be back fed would likely open smokelessly.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Okay so how would you correctly phase a 120V trany. Are you talking the load side as correctly phased. Of course my tranies were electronic not magnetic.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Now I only have 58 tranies.... LOL
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I did assume you guys were correct but I was hoping you weren't.Yes, but I couldn't resist.............
I don't know how exactly Denis' transformers were configured but I would guess something along the lines of a switched-mode power supply (SMPS).
The input is rectified and feeds a high frequency inverter. The high frequency allows the use of a small transformer to get from one voltage level to another then a 60Hz inverter. Given that the application is lighting the shape of waveform isn't critical and there would be no need to synchronise it with the input.
On that basis it was a fair guess that it would be pretty unlikely that the output from two independent units would be in sync or in phase.
Fizzle, fizzle, bang..........
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