Post by thread:[EE]: Non Polar Electrolytic Capacitor

Good way to blow up two polarized capacitors in rapid succession! bgd -----Original Message----- From: pic microcontroller discussion list [.....PICLISTKILLspam@spam@MITVMA.MIT.EDU]On Behalf Of Anand Dhuru Sent: Tuesday, January 30, 2001 9:29 PM To: PICLISTKILLspamMITVMA.MIT.EDU Subject: Re: [EE]: Non Polar Electrolytic Capacitor Hi, the trick is to use TWO polarised caps in Series, connecting EITHER the 2 positives OR the 2 negatives together. Of course, each of the two should be twice of the desired effective final non-polarised value. The 2 free ends are the leads of your non-polarised cap. Your case, u'd require 2 nos of 10uF, 66V caps. Regards, Anand ----- Original Message ----- From: Alan R Aldaba <.....piclistKILLspam.....EDSAMAIL.COM.PH> To: <EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU> Sent: Wednesday, January 31, 2001 09:29 AM Subject: [EE]: Non Polar Electrolytic Capacitor > Hi, I have a trouble finding a replacement part in our area..Does anyone know how to built a non polar electrolytic capacitor from two polar electrolytic capacitors, i need a value of 4.7 uF/ 80 volts to be used in a power amp..I remember reading it elsewhere but I cant remember the details..Thanks {Quote hidden}> > __________________________________ > http://www.edsamail.com > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listservspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body > > > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email @spam@listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email KILLspamlistservKILLspammitvma.mit.edu with SET PICList DIGEST in the body

Don't even think about it ! ( if you care at your transistors...) Vasile On Wed, 31 Jan 2001, Alan R Aldaba wrote: {Quote hidden}> Hi, I have a trouble finding a replacement part in our area..Does anyone know how to built a non polar electrolytic capacitor from two polar electrolytic capacitors, i need a value of 4.7 uF/ 80 volts to be used in a power amp..I remember reading it elsewhere but I cant remember the details..Thanks > > __________________________________ > http://www.edsamail.com > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email RemoveMElistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body > > -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestspamBeGonemitvma.mit.edu

> Hi, I have a trouble finding a replacement part in our area.. > Does anyone know how to built a non polar electrolytic capacitor > from two polar electrolytic capacitors, > i need a value of 4.7 uF/ 80 volts to be used in a power amp.. > I remember reading it elsewhere but I cant remember the details. 1. While you CAN do this you are probably better off using a range of various plastic capacitor types at this voltage rating and/or "motor start" capacitors of about this value but with much higher voltage ratings. Both these should work well in your application. If you MUST use polarised caps, try this. 2. Connect two capacitors, each of the desired capacitance, positive to positive. ACROSS each capacitor connect a diode (one diode for each capacitor) with the anode connected to the capacitor negative terminal and the cathode (stripe on diode) connected to the capacitor positive terminal. That is, the diode will conduct when the REVERSE polarity is applied to the capacitor. Each capacitor should be the required initial; capacitance and NOT double the value as would be the case when placing capacitors in series in a normal way. In your case use 2 x 4.7 uF caps rated at 100 volts or more. Leaving out the diodes will destroy the capacitors in a power application. regards Russell McMahon _____________________________ What can one man* do? Donate food daily free !!! - http://www.thehungersite.com/ Donate Vitamin A! http://www.thechildsurvivalsite.com/ http://www.rawa.com - one perspective on Afghanistan http://www.changingourworld.com http://www.easttimor.com http://www.sudan.com (* - or woman, child or internet enabled intelligent entity :-)) {Quote hidden}> > __________________________________ > http://www.edsamail.com > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email TakeThisOuTlistservEraseMEspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body > > > -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestTakeThisOuTmitvma.mit.edu

{Quote hidden}> -----Original Message----- > From: Russell McMahon [SMTP:apptechEraseME.....CLEAR.NET.NZ] > Sent: Wednesday, January 31, 2001 10:31 AM > To: EraseMEPICLISTMITVMA.MIT.EDU > Subject: Re: [EE]: Non Polar Electrolytic Capacitor > > > Hi, I have a trouble finding a replacement part in our area.. > > Does anyone know how to built a non polar electrolytic capacitor > > from two polar electrolytic capacitors, > > i need a value of 4.7 uF/ 80 volts to be used in a power amp.. > > I remember reading it elsewhere but I cant remember the details. > > > 1. While you CAN do this you are probably better off using a range of > various plastic capacitor types at this voltage rating and/or "motor > start" > capacitors of about this value but with much higher voltage ratings. Both > these > should work well in your application. > > If you MUST use polarised caps, try this. > > 2. Connect two capacitors, each of the desired capacitance, positive to > positive. > ACROSS each capacitor connect a diode (one diode for each capacitor) with > the anode connected to the capacitor negative terminal and the cathode > (stripe on diode) connected to the capacitor positive terminal. That is, > the > diode will conduct when the REVERSE polarity is applied to the capacitor. > > Each capacitor should be the required initial; capacitance and NOT double > the value as would be the case when placing capacitors in series in a > normal > way. > In your case use 2 x 4.7 uF caps rated at 100 volts or more. > > Leaving out the diodes will destroy the capacitors in a power application. > I have used this method before, but for audio applications I suspect that this is a bad idea, the effect of a pair of diodes swithing on and off every cycle is definately not going to help audio quality. I strongly suggest either number 1) above or getting the correct replacement . Mike -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestEraseMEEraseMEmitvma.mit.edu

> 2. Connect two capacitors, each of the desired capacitance, positive to > positive. > ACROSS each capacitor connect a diode (one diode for each capacitor) with > the anode connected to the capacitor negative terminal and the cathode > (stripe on diode) connected to the capacitor positive terminal. That is, the > diode will conduct when the REVERSE polarity is applied to the capacitor. > > Each capacitor should be the required initial; capacitance and NOT double > the value as would be the case when placing capacitors in series in a normal > way. > In your case use 2 x 4.7 uF caps rated at 100 volts or more. I don't like this circuit at all because it acts like one capacitor as the other is charging up, but will act like two capacitors in series once both have been charged up. There will also be sudden jumps in the characteristic as the diodes go off and on. Note that there is no way for either capacitor to discharge, so eventually it will act as two capacitors in series with the diodes no longer coming on. Once that stage is reached, the effective capacitance will be half of either capacitor. In short, don't do it this way. ***************************************************************** Olin Lathrop, embedded systems consultant in Devens Massachusetts (978) 772-3129, RemoveMEolinspam_OUTKILLspamembedinc.com, http://www.embedinc.com -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestTakeThisOuTspammitvma.mit.edu

Did nobody see my original reply to this? :o) I'll repeat, when I was trained back in the valve days, it was taught as correct practice to replace NP caps with two polarised caps in series, reverse. It was also taught that that is basically what is inside a NP cap, and that is why they are 2x bigger physically. What's more the construction of some of the earlier NP caps was in fact two cans back to back with a rubber seal at each end (axial type). If my memory is not too rusty we disected one of these in class. Over the last 20 years TV servicing I have used this technique hundreds of times in situations where it was not worth the wait to order a specialised cap. I have NEVER had one fail, even in the hot overworked TV environment and some of these sets are still owned and used by friends. Diodes?? Ha ha! You guys are killin' me! ;o) -Roman Michael Rigby-Jones wrote: {Quote hidden}> > > Hi, I have a trouble finding a replacement part in our area.. > > > Does anyone know how to built a non polar electrolytic capacitor > > > from two polar electrolytic capacitors, > > > i need a value of 4.7 uF/ 80 volts to be used in a power amp.. > > > I remember reading it elsewhere but I cant remember the details. > > > > > > 1. While you CAN do this you are probably better off using a range of > > various plastic capacitor types at this voltage rating and/or "motor > > start" > > capacitors of about this value but with much higher voltage ratings. Both > > these > > should work well in your application. > > > > If you MUST use polarised caps, try this. > > > > 2. Connect two capacitors, each of the desired capacitance, positive to > > positive. > > ACROSS each capacitor connect a diode (one diode for each capacitor) with > > the anode connected to the capacitor negative terminal and the cathode > > (stripe on diode) connected to the capacitor positive terminal. That is, > > the > > diode will conduct when the REVERSE polarity is applied to the capacitor. > > > > Each capacitor should be the required initial; capacitance and NOT double > > the value as would be the case when placing capacitors in series in a > > normal > > way. > > In your case use 2 x 4.7 uF caps rated at 100 volts or more. > > > > Leaving out the diodes will destroy the capacitors in a power application. > > > I have used this method before, but for audio applications I suspect that > this is a bad idea, the effect of a pair of diodes swithing on and off every > cycle is definately not going to help audio quality. > > I strongly suggest either number 1) above or getting the correct replacement > . > > Mike > > -- > http://www.piclist.com hint: To leave the PICList > EraseMEpiclist-unsubscribe-requestspamspamBeGonemitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList RemoveMEpiclist-unsubscribe-requestKILLspammitvma.mit.edu

Can I use it safely in a power amp, the part is directly connected to the collector of the output transistor and ground, what function does it serves? pic microcontroller discussion list wrote: {Quote hidden}>Did nobody see my original reply to this? :o) > >I'll repeat, when I was trained back in the >valve days, it was taught as correct practice >to replace NP caps with two polarised caps >in series, reverse. It was also taught that >that is basically what is inside a NP cap, >and that is why they are 2x bigger physically. >What's more the construction of some of the >earlier NP caps was in fact two cans back to back >with a rubber seal at each end (axial type). >If my memory is not too rusty we disected one >of these in class. > >Over the last 20 years TV servicing I have >used this technique hundreds of times in >situations where it was not worth the wait >to order a specialised cap. I have NEVER >had one fail, even in the hot overworked TV >environment and some of these sets are still >owned and used by friends. > >Diodes?? Ha ha! You guys are killin' me! ;o) >-Roman > > > >Michael Rigby-Jones wrote: >> > > Hi, I have a trouble finding a replacement part in our area.. >> > > Does anyone know how to built a non polar electrolytic capacitor >> > > from two polar electrolytic capacitors, >> > > i need a value of 4.7 uF/ 80 volts to be used in a power amp.. >> > > I remember reading it elsewhere but I cant remember the details. >> > >> > >> > 1. While you CAN do this you are probably better off using a range of >> > various plastic capacitor types at this voltage rating and/or "motor >> > start" >> > capacitors of about this value but with much higher voltage ratings. Both >> > these >> > should work well in your application. >> > >> > If you MUST use polarised caps, try this. >> > >> > 2. Connect two capacitors, each of the desired capacitance, positive to >> > positive. >> > ACROSS each capacitor connect a diode (one diode for each capacitor) with >> > the anode connected to the capacitor negative terminal and the cathode >> > (stripe on diode) connected to the capacitor positive terminal. That is, >> > the >> > diode will conduct when the REVERSE polarity is applied to the capacitor. >> > >> > Each capacitor should be the required initial; capacitance and NOT double >> > the value as would be the case when placing capacitors in series in a >> > normal >> > way. >> > In your case use 2 x 4.7 uF caps rated at 100 volts or more. >> > >> > Leaving out the diodes will destroy the capacitors in a power application. >> > >> I have used this method before, but for audio applications I suspect that >> this is a bad idea, the effect of a pair of diodes swithing on and off every >> cycle is definately not going to help audio quality. >> >> I strongly suggest either number 1) above or getting the correct replacement >> . >> >> Mike >> >> -- >> http://www.piclist.com hint: To leave the PICList >> piclist-unsubscribe-requestSTOPspamspam_OUTmitvma.mit.edu > >-- >http://www.piclist.com hint: To leave the PICList >spamBeGonepiclist-unsubscribe-requestSTOPspamEraseMEmitvma.mit.edu > > > > __________________________________ http://www.edsamail.com -- http://www.piclist.com hint: To leave the PICList KILLspampiclist-unsubscribe-requestspamBeGonemitvma.mit.edu

Roman, thanks so much for taking up cudgels on my behalf! Regards, Anand. ----- Original Message ----- From: Roman Black <EraseMEfastvidEraseMEEZY.NET.AU> To: <@spam@PICLIST@spam@spam_OUTMITVMA.MIT.EDU> Sent: Thursday, February 01, 2001 03:50 AM Subject: Re: [EE]: Non Polar Electrolytic Capacitor {Quote hidden}> Did nobody see my original reply to this? :o) > > I'll repeat, when I was trained back in the > valve days, it was taught as correct practice > to replace NP caps with two polarised caps > in series, reverse. It was also taught that > that is basically what is inside a NP cap, > and that is why they are 2x bigger physically. > What's more the construction of some of the > earlier NP caps was in fact two cans back to back > with a rubber seal at each end (axial type). > If my memory is not too rusty we disected one > of these in class. > > Over the last 20 years TV servicing I have > used this technique hundreds of times in > situations where it was not worth the wait > to order a specialised cap. I have NEVER > had one fail, even in the hot overworked TV > environment and some of these sets are still > owned and used by friends. > > Diodes?? Ha ha! You guys are killin' me! ;o) > -Roman > > > > Michael Rigby-Jones wrote: > > > > Hi, I have a trouble finding a replacement part in our area.. > > > > Does anyone know how to built a non polar electrolytic capacitor > > > > from two polar electrolytic capacitors, > > > > i need a value of 4.7 uF/ 80 volts to be used in a power amp.. > > > > I remember reading it elsewhere but I cant remember the details. > > > > > > > > > 1. While you CAN do this you are probably better off using a range of > > > various plastic capacitor types at this voltage rating and/or "motor > > > start" > > > capacitors of about this value but with much higher voltage ratings. Both > > > these > > > should work well in your application. > > > > > > If you MUST use polarised caps, try this. > > > > > > 2. Connect two capacitors, each of the desired capacitance, positive to > > > positive. > > > ACROSS each capacitor connect a diode (one diode for each capacitor) with > > > the anode connected to the capacitor negative terminal and the cathode > > > (stripe on diode) connected to the capacitor positive terminal. That is, > > > the > > > diode will conduct when the REVERSE polarity is applied to the capacitor. > > > > > > Each capacitor should be the required initial; capacitance and NOT double > > > the value as would be the case when placing capacitors in series in a > > > normal > > > way. > > > In your case use 2 x 4.7 uF caps rated at 100 volts or more. > > > > > > Leaving out the diodes will destroy the capacitors in a power application. > > > > > I have used this method before, but for audio applications I suspect that > > this is a bad idea, the effect of a pair of diodes swithing on and off every > > cycle is definately not going to help audio quality. > > > > I strongly suggest either number 1) above or getting the correct replacement {Quote hidden}> > . > > > > Mike > > > > -- > > http://www.piclist.com hint: To leave the PICList > > spamBeGonepiclist-unsubscribe-requestKILLspammitvma.mit.edu > > -- > http://www.piclist.com hint: To leave the PICList > .....piclist-unsubscribe-requestspam_OUTmitvma.mit.edu > > > -- http://www.piclist.com hint: To leave the PICList TakeThisOuTpiclist-unsubscribe-request.....TakeThisOuTmitvma.mit.edu

Alan R Aldaba wrote: > > Can I use it safely in a power amp, the part is directly connected to the collector of the output transistor and ground, what function does it serves? I'm not sure what purpose it serves. I am quite sure you can substitute two 10uF 160v caps in series reversed. Then run test it carefully, feel if the caps get warm with no signal, then with playing loud, etc. I can't guarantee it will work, but I would do it. :o) -Roman > >> > > Hi, I have a trouble finding a replacement part in our area.. > >> > > Does anyone know how to built a non polar electrolytic capacitor > >> > > from two polar electrolytic capacitors, > >> > > i need a value of 4.7 uF/ 80 volts to be used in a power amp.. > >> > > I remember reading it elsewhere but I cant remember the details. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads