48 Replies Latest reply on Aug 7, 2014 9:10 AM by simone@panasonic

    HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!

    Resistor+caps

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        • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
          buckybwhiplash

          Greetings Mr. Setsuda

           

          I just replaced the capacitors in my Lincoln SP250 wire feed welder after they went off like volcanoes inside my machine while I was working on a project. While I was welding, I could hear them venting and stopped in the middle of my weld to witness this hideous cloud of white smoke fuming from my machine. I think I incorrectly made the assumption that since my machine was still working when this happened and the screw connections on the old capacitors exhibited signs of arching, I could get away with just replacing them. I was able to find replacements with similar specs from Newark except the new caps were physically smaller.

           

          Old:

          MEPCO/CENTRALABS

          S13490-120

          3120 EG303U050AMA5

          30000 UF -10 + 75%

          50 VDC 75 SURGE

          85 C MAX AMBIENT

          362 9016 56699

          2.0 OD X 5.12 LG

           

          New:

          UNITED CHEMI-CON

          E32D500HPN333MAB7ME32D500HPN333MAB7M

          33000 UF +-20%

          50V

          105 C MAX AMBIENT

          1.38 OD X 4.60 LG

           

          After I put the new caps in the machine, I went to tack a couple of pieces of metal togeter and noticed the output of the welder was much lower than it should have been for the machine setting. After the third tack, one of the new caps vented and I shut the machine off.

           

          Being that I'm just a mechanical designer, my electrical skills are pretty weak (obviously) and I'd like to get some advice from someone with more experience. I'm wondering if there are any components in the circuit I should test (rectifier/diodes, transformer, block, etc.) that could be the source of the trouble or did I just completely miss the mark on using these caps as a replacement. Any help would be greatly appreciated.

           

          Dave Buckalew

          • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
            userzz1

            Dear Mr Setsuda

             

            Pulse discarge capacitor

             

            I have an application where I need to charge a large capacitor to 96V and then discarge it across a low resistance soleniod, this will not happen very often.

            I am thinking of using a Panasonic capacitor EETUQ2C272EA (2700uF, 160V).

            Is there a different capacitor that would be more suitable for this kind of pulse discharge application?

            Kind regards

            Nico Rotolo

            • How to make low capacitance measurements
              MAKeller

              Hiroshi,

               

              I am looking for a way to measure some fuel quantity probes.

              This would an AC capacitance measurement of 30 pF, with a tolerance of +/- .3 pF and resolution of .05 pF.

               

              Do you have any recommendations on a LCR to make this measurement in a manufacturing enviroment.

               

              Thank you,

               

              MA.Keller

              • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                battler

                Hi Mr. Setsuda,

                 

                I am designing a power supply circuit which will use supercapacitors for backup.

                 

                I was wondering if supercapacitors have discharge current ratings? This pdf below (on bottom of page 3) seem to imply that there are limits on operating currents for supercaps, but there was nothing on the product page or data sheet itself regarding current.

                 

                Also, I am thinking of using a supercapacitor charger in the circuit. Is it safe to set up the charge voltage limit at exactly the maximum voltage rating of the supercap, or is it a bad idea? For example, setting maximum voltage limit to 2.5V on 2.5V supercaps. Will they blow / degrade quickly if they are cycled to maximum capacity regularly?

                 

                Thank you,

                 

                 

                Irving

                  • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                    No1@Panasonic_Capacitor.com

                    Hello Irving san

                     

                    >I am designing a power supply circuit which will use supercapacitors for backup.

                     

                    ---->Super capacitors is My competitor 'N' bland.

                          Please note Panasonic EDLC(Electronic double layer capacitor) bland name is 'Gold Capacitor'.

                         But Thank you for your EDLC request to Element 14.

                     

                    >I was wondering if supercapacitors have discharge current ratings? This pdf below (on bottom of page 3)

                    >seem to imply that there are limits on operating currents for supercaps,

                    >but there was nothing on the product page or data sheet itself regarding current.

                     

                    --->I do not understand your PDF in above question, Could you attach your PDF again?

                        and

                        What discharge current value do you need?

                     

                     

                    > Also, I am thinking of using a supercapacitor charger in the circuit.

                    > Is it safe to set up the charge voltage limit at exactly the maximum voltage rating of the supercap,

                    > or is it a bad idea? For example, setting maximum voltage limit to 2.5V on 2.5V supercaps.

                    > Will they blow / degrade quickly if they are cycled to maximum capacity regularly?

                     

                    --->Basically You can use 2.5V charging voltage for 2.5V EDLC Gold cap.

                         But depend on your request life time and charging/Discharging profile,

                         We must propose suitable EDLC.

                         Please see attached file.

                         Here is Gold cap requirement sheet.

                         Could you please fill into this sheet and send back to me?

                         Then I will reply someting proosal to you.

                     

                    Thanks

                    Setsuda

                         

                     

                     

                     

                    Thank you,

                  • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                    Sophieshome
                    I intend to use Panasonic electrolytic capacitors rated at 450V and in normal operation they will have 450V across them, however for a warm up period they may have 470V each time the equipment is switched on.  This warm up period my be about 1 minute. Will this cause extensive shortening of life?  There will be next to no ripple current during the warm up phase.
                    • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                      needs121

                      I am experiencing problems with Tantalum, the price of Tantalum is increasing and the lead time is ridiculous.

                      Does Panasonic have an alternative, my colleague has mentioned that Panasonic has alternative?

                       

                      Please can you let me know what your alternatives might be?

                       

                      Kind regards

                       

                      Graham Murty

                      • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                        JohnDSiviter

                        Hi Hiroshi,

                         

                        I would like your views on the current state of supercaps, their strengths, weaknesses and how the future is going to pan out with these.

                         

                        Thanks,

                        John Technical Team, Farnell.

                        • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                          ElecWiz

                          Hi Mr Setsuda,

                           

                          I am looking at using a Panasonic Gold HZ series Capacitor part number  EECHZ0E335EECHZ0E335 in my design to drive an LED for a period of time

                          Do you have typical application/charging circuit for this type of capacitor?  I would like to know the best circuit for charging the capacitor up to it's rated voltage of 2.5v.

                          Many Thanks.

                            • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                              No1@Panasonic_Capacitor.com

                              Hello Elecwiz san

                               

                              Thank you for your Panasonic EDLC Gold cap inqurily.

                              Please fill your request Charging/Discharging condition into below file.

                              and

                              send back to me.

                              Then I will propose Panasoic suitable EDLC Gold cap.

                               

                               

                              Gold Cap Requirement Checklist
                              Example
                              ApplicationLED Lighting RF-recieve Data buffer
                              Charging ConditionsCharging Voltage? 3,6V or 5,0V
                              Charging Time
                              (Max. / Min.)
                              ? 3600s
                              Charging Current
                              (Balanced Resistor, if any)
                              ? 200Ohm if 3,6V / 7mA if 5,0V suppply
                              Discharging ConditionsBackup Current
                              (Max. / Min. / Typical)
                              ? Typical 32mA
                              Cut-off Voltage? 3,0V-2,7V exxact Value unknown at this time
                              Required Backup Time? 120ms
                              Backup for what
                              (RTC, SRAM, …)
                              ? receive current for RF transceiver
                              Operating ConditionsExpected lifetime? 50000h/100000h/140000h
                              Ambient Temperature
                              (Max. / Min. / Typical)
                              ? min. 5°C / max 55°C / typical 35°C

                               

                               

                              Thanks

                              Setsuda

                            • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                              giamby3000

                              Hi Mr. Setsuda.

                              I'm evaluating  EECRF0H104EECRF0H104 Gold CAP I want to charge this CAP with a battery(4.2V

                              1) On panasonic application note I read: no need of any external resistor because all internal capacitances have to charge and there is many internal resistances, one for any capacitance element. But at the first time, with cap completely discharged, what is the current taken from battery (I suppose to connect CAP in parallel way to battery )? Is there a particular note to connect it to battery?

                               

                              2 Now I suppose CAP completely charged and my battery is very low and I suppose a pulse current with very low intensity(150 uA every second Is EEcRF0H104 choice correct Is Gold cap lifetime destroyed by such current pulsing load

                               

                              Thank you very much.

                               

                                

                              Thanks a lot

                              • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                wonghongyes

                                Dear Mr Setsuda,

                                 

                                could you pls help on explain what is the "CAPACITOR, American symbol" which is device=C-US025-025X050, package=C025-025X050.

                                what type is it ?

                                • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                  giamby3000

                                  Hi Mr. Setsuda.

                                  I'm evaluating EECRF0H104EECRF0H104 Gold CAP. I want to charge this CAP with a battery (4.2V).

                                  1) On panasonic application note I read: no need of any external resistor because all internal capacitances have to charge and there is many internal resistances, one for any capacitance element. But at the first time, with cap completely discharged, what is the current taken from battery (I suppose to connect CAP in parallel way to battery )? Is there a particular note to connect it to battery?

                                   

                                  2) Now I suppose CAP completely charged and my battery is very low and I suppose a pulse current with very low intensity (150 uA every second). Is EECRF0H104EECRF0H104 choice correct? Is Gold cap lifetime destroyed by such current pulsing load?

                                   

                                  Thank you very much.

                                   

                                   

                                  Thanks a lot

                                  • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                    dombrow

                                    Electrolytic Capacitor NNED THIS TYPE OF CAP CAN YOU HELP?

                                    Radial

                                    680 microfarads

                                    250V

                                    DC

                                    20 KHz

                                    Cylindrical

                                    Diameter 35mm

                                    Height 105mm

                                    Screw terminals

                                    70C

                                    • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                      manuelc

                                      Hello Mr. Setsuda,

                                      I have a question about theory of Charge Injection effects in Switching Capacitor Circuits based on MOSFET.
                                      Could you tell me if the voltage across the load (or hold) capacitor in a Switched Capacitor circuit, cause of Charge Injection effect, during the falling time of the gate command voltage of the switch (suppose that it is a pulse generator voltage which goes from 5V (high) to 0V (low)), increases or decreases? Thank you

                                        • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                          No1@Panasonic_Capacitor.com

                                          Hello Emanueie Cuoccio san

                                           

                                          Thank you for your question.

                                          I am not familar Charge Injection effects.

                                           

                                          My understanding of your question is

                                          1)When MOS-FET switch off,

                                          2)Capacitor support MOS-FET.

                                          3)Then current goes into MOS-FET

                                          4)Charge injection effect is happened.

                                          5)Then Capacitor Voltage is increase or decreases?

                                           

                                          is my understanding correct?

                                          Please confirm and reply.

                                           

                                          Sorry for my not enough knowledge,

                                          I will try to do my best.

                                           

                                          Thanks
                                          Setsuda

                                            • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                              manuelc

                                              Yes Mr. Setsuda. Your understanding is correct. I've read that if you measure the voltage across the capacitor along time, you notice that during the falling time of the gate voltage wave there is a spike of voltage in the capacitor's waveform. I want to know if it's correct that this spike is negative (and so there is a sudden decrease of voltage across the capacitor). I've thought that it may be correct if you think that the charge into the channel of the FET moves leaves the channel moving partially towards the generator, and partially towards the capacitor during the switching off of the MOSFET. So that additive negative charge that flows onto capacitor could be considered as cause of a decrease of the voltage across it. Don't worry if it's not your field of study. I have to thank you anyway for your helpfulness. Best regards.      EC

                                                • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                                  No1@Panasonic_Capacitor.com

                                                  Hello Emanuele Cuiccio san

                                                   

                                                  Thank you for your reply.

                                                  Unfortunately I am not familiar about this matter.

                                                  So I asked my old connection about power supply related engineer and got advice below from him.

                                                   

                                                  -----

                                                  this question is really not easy. I’m not really sure if I understood it correct. Assuming that the below circuit is correct understanding the voltage of the output C should be decreased. When switching off the MOSFET the gate has to be discharged and this charge should go into the Cload. Means the voltage should decrease.

                                                   

                                                  Jpeg.jpg

                                                  Hope this help and my answer is fitting to the question ;-)

                                                  -----

                                                   

                                                  Please refer above.

                                                   

                                                  I am afraid to say that

                                                  It is not easy for me to reply clear answer to you.

                                                   

                                                  Thanks

                                                  Setsuda

                                                   

                                                   

                                                   

                                            • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                              giamby3000

                                              Hi Mr. Setsuda.

                                              I'm evaluating EECRF0H104 Gold CAP. I want to charge this CAP with a battery (4.2V).

                                              1) On panasonic application note I read: no need of any external resistor because all internal capacitances have to charge and there is many internal resistances, one for any capacitance element. But at the first time, with cap completely discharged, what is the current taken from battery (I suppose to connect CAP in parallel way to battery )? Is there a particular note to connect it to battery?

                                               

                                              2) Now I suppose CAP completely charged and my battery is very low and I suppose a pulse current with very low intensity (150 uA every second). Is EECRF0H104 choice correct? Is Gold cap lifetime destroyed by such current pulsing load?

                                               

                                              Thank you very much.

                                               

                                               

                                              Thanks a lot

                                                • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                                  No1@Panasonic_Capacitor.com

                                                  Hello Giamby 3000 san

                                                   

                                                  Thank you for your inquiry.

                                                  It seems that Coin tyoe Gold cap may not suitable for your puls requirment.

                                                  Anyway

                                                  Please fill your requirment into attached Gold Cap Check sheet.

                                                  Then I will check.

                                                   

                                                  Gold Cap Requirement Checklist
                                                  Example
                                                  Application RF-recieve Data buffer
                                                  Charging ConditionsCharging Voltage 3,6V or 5,0V
                                                  Charging Time
                                                  (Max. / Min.)
                                                  3600s
                                                  Charging Current
                                                  (Balanced Resistor, if any)
                                                  200Ohm if 3,6V / 7mA if 5,0V suppply
                                                  Discharging ConditionsBackup Current
                                                  (Max. / Min. / Typical)
                                                  Typical 32mA
                                                  Cut-off Voltage 3,0V-2,7V exxact Value unknown at this time
                                                  Required Backup Time 120ms
                                                  Backup for what
                                                  (RTC, SRAM, …)
                                                  receive current for RF transceiver
                                                  Operating ConditionsExpected lifetime 50000h/100000h/140000h
                                                  Ambient Temperature
                                                  (Max. / Min. / Typical)
                                                  min. 5°C / max 55°C / typical 35°C

                                                   

                                                  Thanks
                                                  Setsuda

                                                    • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                                      giamby3000

                                                       

                                                       

                                                       

                                                       

                                                      Gold Cap Requirement Checklist

                                                       

                                                      My application
                                                      Application GSM / GPRS Datalogger
                                                      Charging ConditionsCharging Voltage 3,6V
                                                      Charging Time
                                                      (Max. / Min.)
                                                      3600s
                                                      Charging Current
                                                      (Balanced Resistor, if any)
                                                      ?
                                                      Discharging ConditionsBackup Current
                                                      (Max. / Min. / Typical)
                                                      20 mA for 10 minutes
                                                      Cut-off Voltage 2,5V
                                                      Required Backup Time
                                                      Backup for what
                                                      (RTC, SRAM, …)
                                                      GSM Pulse Current

                                                      0 µA continuous current;

                                                      2000 mA for 577 µs every 4.6 ms

                                                      Operating ConditionsExpected lifetime 140000h
                                                      Ambient Temperature
                                                      (Max. / Min. / Typical)
                                                      min. -20°C / max 60°C / typical 30°C

                                                       

                                                       

                                                      Thank you very much Mr. Hiroshi

                                                  • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                                    richardmuse

                                                    What happens to an Aluminum Electrolytic Capacitor when it is used below its rated temperature. Let's say we have an 180uF cap rated at 450V and the unit that it is installed in drops to below the -40C rating. Does the the capacity (uF) decrease? Does the part explode/disintegrate? Is the part ruined or otherwise rendered disfunctional? What will happen to our power supply's capacitors when it is used in temperatures that are lower than the rated temperatures?

                                                    • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                                      mutazoid

                                                      I have a SyncMaster monitor.

                                                      There are CapXon 25V, 470uF capacitors inside that blew out.

                                                      Im thinking about replacing them, just wondering is there differences in capacitors I should be aware when I go looking.

                                                       

                                                      Thanks for any advice.

                                                       

                                                      Keith

                                                      • Re: HAVE A QUESTION ON CAPACITORS,ASK AN EXPERT!
                                                        mic224

                                                        Dear sir/madam

                                                         

                                                        I was wondering if you could help me please,  i have a faulty capacitor ( 35v_1000uf_85c_9x29mm) this is all i says on it.

                                                         

                                                        I have replaced it with an exact same cap only different in size.

                                                         

                                                        It did work but only when i switched it to power off ( standby) that it blown.

                                                         

                                                        I was wondering if you could help me to understand why it happened and also what are my alternate replacements.

                                                         

                                                        Thank you

                                                         

                                                        Michael