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    Secondary out 32 volts AC getting 146 volts DC do not understand

    I will post a picture of this transformer setup tomorrow I hope someone can shed some light on how this
    could be ( has a bridge rectifier with no capacitors on the DC side on other thing that is strange about this setup is that negative side of the bridge rectifier also goes to machine ground )

    Now if check one wire that to the machine ground and wire one tap that goes to the bridge rectifier the voltage is really wired and when you check the other tap wire that goes to other side of the bridge rectifier this voltage is also is really weird but not 32 volts AC side of the rectifier

    This transformer has multiple secondary outputs and there voltages are different two of the taps go to machine ground ( if I remember correctly there are six fuse one for each tap wires

    Because I just do not understand this at all

    Now it is common to see secondary transformer secondary winding one wire goes to machine ground

    ****but I have not seen on the secondary side after a bridge rectifier that the negative side of the power supply goes to machine ground *****

    **** Does this make scene to anyone **** if it does could you please enlighten me on what the purpose of this is

    I am using a Fluke meter to make these measurements
    Last edited by sam_sam_sam; 08-27-2020, 06:29 PM.
    9 PC LCD Monitor
    6 LCD Flat Screen TV
    30 Desk Top Switching Power Supply
    10 Battery Charger Switching Power Supply for Power Tool
    6 18v Lithium Battery Power Boards for Tool Battery Packs
    1 XBox 360 Switching Power Supply and M Board
    25 Servo Drives 220/460 3 Phase
    6 De-soldering Station Switching Power Supply 1 Power Supply
    1 Dell Mother Board
    15 Computer Power Supply
    1 HP Printer Supply & Control Board * lighting finished it *


    These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

    1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
    2 Hem Saw Computer Stack Board

    All of these had CAPs POOF
    All of the mosfet that are taken out by bad caps

    #2
    Re: Secondary out 32 volts AC getting 146 volts DC do not understand

    deffo needs at least pictures

    Comment


      #3
      Re: Secondary out 32 volts AC getting 146 volts DC do not understand

      A sketched diagram how it is all hooked up will also help.
      Since it is rectified by bridge rectifier and no filter cap, what you see on the output will 120Hz pulsing DC.
      Last edited by budm; 08-27-2020, 08:21 PM.
      Never stop learning
      Basic LCD TV and Monitor troubleshooting guides.
      http://www.badcaps.net/forum/showthr...956#post305956

      Voltage Regulator (LDO) testing:
      http://www.badcaps.net/forum/showthr...999#post300999

      Inverter testing using old CFL:
      http://www.badcaps.net/forum/showthr...er+testing+cfl

      Tear down pictures : Hit the ">" Show Albums and stories" on the left side
      http://s807.photobucket.com/user/budm/library/

      TV Factory reset codes listing:
      http://www.badcaps.net/forum/showthread.php?t=24809

      Comment


        #4
        Re: Secondary out 32 volts AC getting 146 volts DC do not understand

        Originally posted by budm View Post
        A sketched diagram how it is all hooked up will also help.
        Since it is rectified by bridge rectifier and no filter cap, what you see on the output will 120Hz pulsing DC.

        But should I be seeing a voltage that high

        I expected maybe a voltage twice but what I seeing is a little more three times the amount
        Last edited by sam_sam_sam; 08-27-2020, 08:57 PM.
        9 PC LCD Monitor
        6 LCD Flat Screen TV
        30 Desk Top Switching Power Supply
        10 Battery Charger Switching Power Supply for Power Tool
        6 18v Lithium Battery Power Boards for Tool Battery Packs
        1 XBox 360 Switching Power Supply and M Board
        25 Servo Drives 220/460 3 Phase
        6 De-soldering Station Switching Power Supply 1 Power Supply
        1 Dell Mother Board
        15 Computer Power Supply
        1 HP Printer Supply & Control Board * lighting finished it *


        These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

        1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
        2 Hem Saw Computer Stack Board

        All of these had CAPs POOF
        All of the mosfet that are taken out by bad caps

        Comment


          #5
          Re: Secondary out 32 volts AC getting 146 volts DC do not understand

          Originally posted by sam_sam_sam View Post
          But should I be seeing a voltage that high

          I expected maybe a voltage twice but what I seeing is a little more three times the amount
          I do not know about that part yet until we see the pictures and diagram.
          Never stop learning
          Basic LCD TV and Monitor troubleshooting guides.
          http://www.badcaps.net/forum/showthr...956#post305956

          Voltage Regulator (LDO) testing:
          http://www.badcaps.net/forum/showthr...999#post300999

          Inverter testing using old CFL:
          http://www.badcaps.net/forum/showthr...er+testing+cfl

          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
          http://s807.photobucket.com/user/budm/library/

          TV Factory reset codes listing:
          http://www.badcaps.net/forum/showthread.php?t=24809

          Comment


            #6
            Re: Secondary out 32 volts AC getting 146 volts DC do not understand

            if the primary and secondary are both earthed then your going to see partial mains - because your house links earth and N.

            Comment


              #7
              Re: Secondary out 32 volts AC getting 146 volts DC do not understand

              Well I finally figured out why this machine foot pedal controller board causing me such a headache because the board has some issues but still operates the hydraulic cylinders but not with the foot pedal

              This controller is the weirdest setup I have seen in quite some time

              This machine has DC solenoid valves the coils are powered by this controller board power supply
              This controller uses 24 volt relay coils which was throwing me a curve ball

              This customer wants machine to work correctly again with the foot pedal so the solution for this problem is to use the portion of the controller board that still works and power the control relay that operates the valves
              with a new relay mount on the machine and remove the relay from the controller board because I do have any idea where you would find this type of relay ( relay has bad contacts and not repairable)

              Have a separate power supply for the foot pedal relay coil for the solenoid valves with a E stop switch for the foot pedal ( 24 volts DC power supply)

              Some wire that did not have any function to that wire were removed from the controller board

              One note this machine was manufactured in 1992 and made in Portugal

              One other note these relays are open to the elements no plastic cover

              One other note I tried to not use this controller board at all would not work correctly and blew fuses on the control transformer not exactly sure why this was happening this is what drove me to this solution for this problem

              One other weird thing about the way this power supply controller board is setup the board does not use the positive section of the rectifier

              The positive side of rectifier goes to a normally open switch on the main contactor then from there is not clear exactly where it goes but my guess is that it is the other side of each of the solenoid coils but this the part that not clear how it gets there

              One other note the writing diagrams are about the worst I have seen in a long time

              The biggest problem I have is how the 24 volt relays are powered from this board ???

              This customer employees tried to put a new foot pedal on this machine because the one that was on there the switches plastic housing broke into pieces

              ( the old foot pedal had two switches two normally open and two normally close on each switch and has six wires that went to the foot pedal )

              and by them trying to put another foot pedal ( which the OEM part is no longer available and there employees did not understand how you would have to wire the new replacement foot pedal they fried part of controller board or something else but not sure what the something else is

              This customer has other issues where there employees do understand how controls work and mess things up and then the customer call me to see if I fix there mess
              Attached Files
              Last edited by sam_sam_sam; 09-03-2020, 08:49 PM.
              9 PC LCD Monitor
              6 LCD Flat Screen TV
              30 Desk Top Switching Power Supply
              10 Battery Charger Switching Power Supply for Power Tool
              6 18v Lithium Battery Power Boards for Tool Battery Packs
              1 XBox 360 Switching Power Supply and M Board
              25 Servo Drives 220/460 3 Phase
              6 De-soldering Station Switching Power Supply 1 Power Supply
              1 Dell Mother Board
              15 Computer Power Supply
              1 HP Printer Supply & Control Board * lighting finished it *


              These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

              1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
              2 Hem Saw Computer Stack Board

              All of these had CAPs POOF
              All of the mosfet that are taken out by bad caps

              Comment


                #8
                Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                One note about this customer is that most if not all of his equipment is very old and most of electricians do not understand controls on very old equipment which is a big problem because newer machine use 24 volts DC to the foot pedal not this one it was sending 64 volts and higher

                This is a very small shop

                He has another machine that has a problem with what he think is the foot pedal on this one as well

                I look at this transformer again and from what I can see it has three wires and one is tied to the machine ground then there is another two or three wires and one of them goes to ground but only the top section has the rectifier on two of the three wires and not the wire that goes machine ground

                Now I am not sure what the other winding on this transformer power because the wiring diagram is not very clear exactly where they go

                wire one—— wire two——> to rectifier——wire three goes to machine ground
                Between wire one and wire two 32 volts ( I did not check wire one to wire three or wire two to wire three )

                On one last note the only thing that I need to understand is how the contacts on this relay was setup to know how the circuit was layout did not have the time to figure this part out sorry about this
                Last edited by sam_sam_sam; 09-03-2020, 09:29 PM.
                9 PC LCD Monitor
                6 LCD Flat Screen TV
                30 Desk Top Switching Power Supply
                10 Battery Charger Switching Power Supply for Power Tool
                6 18v Lithium Battery Power Boards for Tool Battery Packs
                1 XBox 360 Switching Power Supply and M Board
                25 Servo Drives 220/460 3 Phase
                6 De-soldering Station Switching Power Supply 1 Power Supply
                1 Dell Mother Board
                15 Computer Power Supply
                1 HP Printer Supply & Control Board * lighting finished it *


                These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

                1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
                2 Hem Saw Computer Stack Board

                All of these had CAPs POOF
                All of the mosfet that are taken out by bad caps

                Comment


                  #9
                  Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                  It looks like the relay uses 2 pair of N.C. contacts and 2 pair of N.O. contacts, so any 4PDT should work
                  If the relay contacts are around 3 amp, an Omron MY4, 24 volt should work.
                  or Honeywell SZR-LY4-X1-DC24V 10 amp contacts
                  Last edited by R_J; 09-03-2020, 10:18 PM.

                  Comment


                    #10
                    Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                    I think you might be reading stray voltage due to leakage currents. Does your multimeter have LoZ capability? Or put a 20k resistor across the leads so the multimeter is not so sensitive.

                    I was looking for where the transformer's secondary gets connected to earth-ground. Before or after the bridge rectifier.
                    I can't see the pcb traces around the bridge rectifier, but it looks like two red wires (32VAC from the transformer to #94, earth-ground to #93 and a mystery wire to #92. The pcb jumper below that terminal block seems to also connect to the relays. They're supposed to have a clear cover on them, the contacts look a bit bent and burnt dead. There is no arc snubber for them.

                    I would remove the pcb, take pics of the backside to draw out the schematic. You don't need three DPDT relays for this. But the voltage readings are still confusing.
                    The relays might be machine safety relays.

                    adira E06-00040 relay board
                    Attached Files
                    Last edited by redwire; 09-03-2020, 10:27 PM.

                    Comment


                      #11
                      Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                      If a terminal is not used from the bridge rectifier, it might be a bipolar solenoid drive? So +ve 1/2 wave DC pulls it in, and -ve 1/2 wave DC pushes it out. Instead of simply solenoid on or off.
                      The foot pedal double switches might again be a safety function.

                      Comment


                        #12
                        Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                        This is the relay that I am using
                        Omron LY4F-DC24 because this one has a rating of 10 amps contacts ( plus it has a LED indicator light )
                        It just one set of contacts that are not being used

                        This is what I used
                        One set of normally open
                        Two sets of normally close
                        Last edited by sam_sam_sam; 09-04-2020, 05:40 AM.
                        9 PC LCD Monitor
                        6 LCD Flat Screen TV
                        30 Desk Top Switching Power Supply
                        10 Battery Charger Switching Power Supply for Power Tool
                        6 18v Lithium Battery Power Boards for Tool Battery Packs
                        1 XBox 360 Switching Power Supply and M Board
                        25 Servo Drives 220/460 3 Phase
                        6 De-soldering Station Switching Power Supply 1 Power Supply
                        1 Dell Mother Board
                        15 Computer Power Supply
                        1 HP Printer Supply & Control Board * lighting finished it *


                        These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

                        1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
                        2 Hem Saw Computer Stack Board

                        All of these had CAPs POOF
                        All of the mosfet that are taken out by bad caps

                        Comment


                          #13
                          Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                          Originally posted by redwire View Post
                          If a terminal is not used from the bridge rectifier, it might be a bipolar solenoid drive? So +ve 1/2 wave DC pulls it in, and -ve 1/2 wave DC pushes it out. Instead of simply solenoid on or off.
                          The foot pedal double switches might again be a safety function.
                          You might be right about this part that “ Instead of simply solenoid on or off.“
                          You are probably right about this part as well “ The foot pedal double switches might again be a safety function. ?

                          Before I remove the non functional wires off the board I tried different combinations ( by closing the other two relays ) to get the board to activate the valve control relay but could not get it to activate so this is what drove me to what I explained earlier

                          One other note someone has modified the front control panel with different switches so who knows what has been bypassed but it was working before but every once in while it would blow a fuse for the controller board on the control transformer so it was having issues anyway

                          This brings me to this question my plan is to use both sets of normally open switch to control the value relay coil

                          The plan is to wire the two normally open switch contacts in series in the foot pedal switches to the power supply and hook it up to the control relay for valve with a E stop switch install in circuit

                          Should I do more than this if so please explain why

                          Thanks
                          Last edited by sam_sam_sam; 09-04-2020, 05:16 AM.
                          9 PC LCD Monitor
                          6 LCD Flat Screen TV
                          30 Desk Top Switching Power Supply
                          10 Battery Charger Switching Power Supply for Power Tool
                          6 18v Lithium Battery Power Boards for Tool Battery Packs
                          1 XBox 360 Switching Power Supply and M Board
                          25 Servo Drives 220/460 3 Phase
                          6 De-soldering Station Switching Power Supply 1 Power Supply
                          1 Dell Mother Board
                          15 Computer Power Supply
                          1 HP Printer Supply & Control Board * lighting finished it *


                          These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

                          1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
                          2 Hem Saw Computer Stack Board

                          All of these had CAPs POOF
                          All of the mosfet that are taken out by bad caps

                          Comment


                            #14
                            Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                            Originally posted by redwire View Post
                            I think you might be reading stray voltage due to leakage currents. Does your multimeter have LoZ capability? Or put a 20k resistor across the leads so the multimeter is not so sensitive.

                            I was looking for where the transformer's secondary gets connected to earth-ground. Before or after the bridge rectifier.
                            I can't see the pcb traces around the bridge rectifier, but it looks like two red wires (32VAC from the transformer to #94, earth-ground to #93 and a mystery wire to #92. The pcb jumper below that terminal block seems to also connect to the relays. They're supposed to have a clear cover on them, the contacts look a bit bent and burnt dead. There is no arc snubber for them.

                            I would remove the pcb, take pics of the backside to draw out the schematic. You don't need three DPDT relays for this. But the voltage readings are still confusing.
                            The relays might be machine safety relays.

                            adira E06-00040 relay board
                            #92 is the positive side of the rectifier and as I pointed out earlier this terminal does not go to anything on the board but does go to a switch on the main contactor and goes some where in the machine

                            I did use a 120 volt incandescent light bulb and still measured 60 something volt for the wires to the foot pedal switches and like I said earlier this is weird

                            I have seen 24 volts AC
                            I have seen 24 volts DC this is rare
                            I have seen 120 volts Ac this is a not common setup but on older machines
                            But I have not seen 60 something DC volts

                            One note this repair on this machine is costing him money for this repair ( because most of the repairs before on this machine have been miner repairs and did not charge much money for this type of repairs )

                            One reinforcing my pull behind trailer ( for my truck ) with angel steal beams on the deck and the ramp of the trailer ( I am providing the material for my trailer repair )
                            And cash for the rest of the payment

                            This is a side job so I work on this machine project whenever I have some free time to work on it after my regular job where I work
                            Last edited by sam_sam_sam; 09-04-2020, 05:58 AM.
                            9 PC LCD Monitor
                            6 LCD Flat Screen TV
                            30 Desk Top Switching Power Supply
                            10 Battery Charger Switching Power Supply for Power Tool
                            6 18v Lithium Battery Power Boards for Tool Battery Packs
                            1 XBox 360 Switching Power Supply and M Board
                            25 Servo Drives 220/460 3 Phase
                            6 De-soldering Station Switching Power Supply 1 Power Supply
                            1 Dell Mother Board
                            15 Computer Power Supply
                            1 HP Printer Supply & Control Board * lighting finished it *


                            These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

                            1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
                            2 Hem Saw Computer Stack Board

                            All of these had CAPs POOF
                            All of the mosfet that are taken out by bad caps

                            Comment


                              #15
                              Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                              I would use some relays that are easy to get and fully enclosed. I'd also change the relay voltage. There isn't very much on that board.

                              The next thing: only because the original relay has 24V coil voltage written on it, doesn't mean there should be 24V. It could be 32V, it also could be 18V...

                              Comment


                                #16
                                Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                                It's definitely a machine-safety system. They use relay logic for AND and OR, including the foot pedal.
                                Safety relays- so one set of stuck contacts does not prevent any others from moving, unlike usual DPDT relays or the Omron LY4F which jam if any contact arcs stuck.
                                Interlocks galore - if the foot pedal is open-circuit, ground fault or the foot-pedal up switch contacts are not asserted, it will never give out a foot-pedal down signal to energize the solenoid.
                                If the solenoid is on and a foot-pedal up is seen (i.e. stuck down), de-energize the solenoid regardless if a foot-pedal down is seen/stuck on.

                                It looks like just a DC power supply but rectifier (+) goes through E-stop and something else to make it back to the board. Have to see the wiring diagram and board backside to finish any meaningful schematic.
                                The original problem might be a ground fault somewhere else, on the solenoids or other transformer windings.
                                I find most of my labour cost for fixing plant stuff is just figuring out the wiring. Once I spent a day on a CNC machine just finding a wiring diagram, following wires to the correct fuse holders.

                                I don't want to give out advice if you're going to strip out all the safety interlocks/relays. I'm assuming the machine can hurt people if it malfunctions, so the manufacturer did it that way originally.
                                The foot-pedal is complicated with six wires and two switches to keep it safe.

                                Comment


                                  #17
                                  Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                                  redwire
                                  I know you do not give advice but I did give your advice some real thought and decided to use a safety relay and the other relay I mentioned earlier or something similar for the foot pedal relay

                                  One problem with the wiring diagram has a lot to be desired it does not show the wiring for the foot pedal correctly and the wire numbers do not match so it going to be very difficult to try to figure out what when wrong and some of the controls have been modified or have been disabled like it does not have a “ E “ stop
                                  which I am going to be adding this customer also want to add a key switch so other employees can not use it unless they have the key for the machine

                                  I am going to use a safety relay G7S-3A3B-E DC24
                                  Here is the link to where I buying if from

                                  https://www.digikey.com/product-deta...598-ND/2755411

                                  G7S-3A3B-E
                                  24VDC + 0 / 1 coil

                                  13 / 14 normally open 33 / 34 normally open 51 / 52 normally closed

                                  23 / 24 normally open 41 / 42 normally closed 61 / 62 normally closed

                                  One set of contacts are not going to be used pins 23 / 24 are not need

                                  I going to use pins 51 / 52 and pins 61 / 62 in series for in case the other pins were welded then the safety relay would not rein gauge the foot pedal relay again

                                  I am also going to use a 24 volt switching power supply for the two relay because there is no 24 volts available on this machine and because I want to controls circuit to be 24 volts

                                  For your comment about “ I'm assuming the machine can hurt people if it malfunctions “

                                  no it would only keep the blade in the down position and you would not be able to do anything else with it but I am also going to add a limit switch for the blade when it is all way down it goes back up in the neutral position unless the safety relay malfunction it would keep the blade in the down position

                                  Because the up function does not work correctly either or it did not have this function to begin with because some of these machine did have a automatic blade up function

                                  also some machine have a function that you can leave the blade in the down position when you turn the machine off this machine does not need this function because the cylinder rod length is very short and does not suffer from leaking down sin drum like a lot of machine do
                                  Last edited by sam_sam_sam; 09-17-2020, 10:32 PM.
                                  9 PC LCD Monitor
                                  6 LCD Flat Screen TV
                                  30 Desk Top Switching Power Supply
                                  10 Battery Charger Switching Power Supply for Power Tool
                                  6 18v Lithium Battery Power Boards for Tool Battery Packs
                                  1 XBox 360 Switching Power Supply and M Board
                                  25 Servo Drives 220/460 3 Phase
                                  6 De-soldering Station Switching Power Supply 1 Power Supply
                                  1 Dell Mother Board
                                  15 Computer Power Supply
                                  1 HP Printer Supply & Control Board * lighting finished it *


                                  These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

                                  1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
                                  2 Hem Saw Computer Stack Board

                                  All of these had CAPs POOF
                                  All of the mosfet that are taken out by bad caps

                                  Comment


                                    #18
                                    Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                                    One note about the blade being kept in the down position I would have to check how I would have this function work
                                    9 PC LCD Monitor
                                    6 LCD Flat Screen TV
                                    30 Desk Top Switching Power Supply
                                    10 Battery Charger Switching Power Supply for Power Tool
                                    6 18v Lithium Battery Power Boards for Tool Battery Packs
                                    1 XBox 360 Switching Power Supply and M Board
                                    25 Servo Drives 220/460 3 Phase
                                    6 De-soldering Station Switching Power Supply 1 Power Supply
                                    1 Dell Mother Board
                                    15 Computer Power Supply
                                    1 HP Printer Supply & Control Board * lighting finished it *


                                    These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

                                    1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
                                    2 Hem Saw Computer Stack Board

                                    All of these had CAPs POOF
                                    All of the mosfet that are taken out by bad caps

                                    Comment


                                      #19
                                      Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                                      Euro standards for machines have redundant safety controls.
                                      A pic of the pcb backside would make it easy to figure out, I can draw a schematic.

                                      This thing will arc and kill any relay you use to switch power to the solenoid. It needs a snubber or back-EMF diode for the solenoid, and there's no capacitor at all even 0.1uF on the DC bridge to stop HV from killing the bridge rectifier. The 146V reading might even be from insulation failing somewhere due to this.

                                      The danger is possibly if the blade moves down by itself?- due to the footswitch cord gets stepped on, damaged connector etc.?
                                      I'll look for a example safety-relay redundant connection circuit to explain what they originally tried to do.

                                      Comment


                                        #20
                                        Re: Secondary out 32 volts AC getting 146 volts DC do not understand

                                        “ A pic of the pcb backside would make it easy to figure out, I can draw a schematic.”
                                        I will try to do this when I go back there to work on it again

                                        “ This thing will arc and kill any relay you use to switch power to the solenoid. It needs a snubber or back-EMF diode for the solenoid, and there's no capacitor at all even 0.1uF on the DC bridge to stop HV from killing the bridge rectifier.

                                        The 146V reading might even be from insulation failing somewhere due to this.”
                                        ( please explain what you mean by this statement )

                                        This voltage has been this high every scene I have worked on now that not to say there has been something wrong with it for a while because when the original foot pedal worked it would blow one of the fuses on the control transformer for the controller board ( it would do this every once in a while ) ( sometimes it would blow the fuse so bad that it would be a dark black color and then sometimes it would be very clear that you could not tell that the fuse blew ) all fuse are 3.15 amps

                                        As far as the relay killing part of it you can see what is on this board there is nothing other some diodes

                                        “ I'll look for a example safety-relay redundant connection circuit to explain what they originally tried to do. “

                                        I would really appreciate if you would do this for me Thanks


                                        This 146 volts dc voltage has puzzled me for a while that is the reason for starting this post in the first place

                                        This is what does not make scene to me

                                        I understand the reason you would machine ground the secondary winding this is done on a lot machine
                                        I understand the reason you would one side of a switching power supply to machine ground

                                        But what I do not understand why you would ground the secondary winding in two places and then do the same thing after the bridge recdefier this part ( I just do not understand why you would do both ) unless you are doing this for the dc voltage but then you would have ac voltage on top of the dc voltage rail would you

                                        Most of the time you do not have so many secondary winding like this transformer is and so many fuses

                                        We have a machine that use the same setup but it has a different ( one ) fuse for each voltage output however if it does do this I do not know where it is done but it is not done at the transformer ( this one only has 3 different voltages ) 24 volts 120 volts 220 volts ( I know it done some where because we had a short on the 120 volt tap before and it had blown that fuse )

                                        You might have a selection of taps for different voltages but only the voltage that you want to use is selected
                                        Last edited by sam_sam_sam; 09-20-2020, 07:02 AM.
                                        9 PC LCD Monitor
                                        6 LCD Flat Screen TV
                                        30 Desk Top Switching Power Supply
                                        10 Battery Charger Switching Power Supply for Power Tool
                                        6 18v Lithium Battery Power Boards for Tool Battery Packs
                                        1 XBox 360 Switching Power Supply and M Board
                                        25 Servo Drives 220/460 3 Phase
                                        6 De-soldering Station Switching Power Supply 1 Power Supply
                                        1 Dell Mother Board
                                        15 Computer Power Supply
                                        1 HP Printer Supply & Control Board * lighting finished it *


                                        These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

                                        1 Over Head Crane Current Sensing Board ( VFD Failure Five Years Later )
                                        2 Hem Saw Computer Stack Board

                                        All of these had CAPs POOF
                                        All of the mosfet that are taken out by bad caps

                                        Comment

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