Hammond transformer dual primary and regular secondary question

Discussion in 'General Electronics Chat' started by kbyrne, Sep 14, 2017.

  1. kbyrne

    Thread Starter Active Member

    Dec 10, 2011
    92
    2
    With my electricity at 115 VAC do I use a hammond with dots connected then other wires connected. One plug to dot and one plug wire to no dot. That would make up a parallel primary connection with 115vac input. Or would I hook up only one
    set of primary wires. My schematic is different on my box than this pdf. Parallel causes a buzzing noise and I shut off power strip right away with transformer mounted on wood and wires insulated with white color euro type connector. I need this type of transformer clarified if anyone could help me. Part number 186F48 48VCT @ 2A.
     
  2. RichardO

    Late Member

    May 4, 2013
    2,274
    890
    It appears that you do not have the right phase of the connections for the primary or secondary. Double check your pin numbers.

    Without a schematic of how you wired the transformer any further answers are impossible.
     
  3. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
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    1,526
    Your transformer should look like fig. 6D here. If it doesn't then ignore the information below.
    You should connect pins 1 & 4 to one side of the mains and pins 2 & 5 to the other mains wire.
     
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  4. MaxHeadRoom

    Expert

    Jul 18, 2013
    16,226
    4,763
    If operating on 120vac then all you need to do is connect one ends of each pair together, and supply power to this junction and ONE of the other ends, then measure from each of the open end to the other, and the voltage will either be 120v or close to zero.
    If 120v, swap one of the primary pair and connect in parallel.
    Max.
     
  5. kbyrne

    Thread Starter Active Member

    Dec 10, 2011
    92
    2
    My transformer is indeed 6D. Every thing that I know goes by the pin with the black pulse dot. Pin one and two continuity beep ok
    Which pin will be AC1 Pin with pulse dot?
     
  6. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
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    6D shows the physical transformer with the pins numbered and the schematic symbol shows pin numbers and dots.
     
  7. kbyrne

    Thread Starter Active Member

    Dec 10, 2011
    92
    2
    28.09ACV measured each side of transformer after pin 1 & 4 connected then pins 2 & 5 connected. Mains to pin 1
    other mains to pin 5. Secondary side AC1 pin 6, GND pin 8 and AC2 pin 10 if I understand all of this you have stated. 28VAC times 1.414 = 39.59DC both sides of rails. Why only 36DC? Filter cap size? Mains measure 117.3ACV.
     
  8. AlbertHall

    AAC Fanatic!

    Jun 4, 2014
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    Where is this 36V DC?
    The size of the filter capacitor depends on how much current you need and how much ripple is acceptable.
    Read here.
     
  9. kbyrne

    Thread Starter Active Member

    Dec 10, 2011
    92
    2
    Old power supply board still working. Circuit needed 1 Amp per rail. Filter cap is 4700uf @ 50VDC . 36VDC is with a transformer 24VAC at two Amps. Miss print up above post, sorry. I have two transformers in mind one 48VCT center tap and one 24VAC. 24VAC is not center taped.
     
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