the limits are <1000 x <1000 pixels no matter how small the file size and <100kB and match the restricted range of acceptable formats,jlcastro77 said:I wonder why I cannot upload an image directly to this post. The size is 1024x768 or 800x600 at 734kb file size...
most of which are compressed.
If by pass capacitors you will need units that can hold twice your rail supply ...
voltage.... if rail voltage is 70... so you will need 150 volts and upper voltages.... not really needed enormous sized condensers as some 630 volts units are.
selecting capacitors into a voltage range that is twice the rail supply voltage, or rail to rail voltage is already an overkill.
In my home i use the same supply voltage..and i am doing this those last 48 years long and NEVER had any condenser or capacitor burned, with leakage or exploded.
If the 4N7 is the one near the zener diode into the input circuit... well... there you have not more than the zener voltage... any unit you find may fit.... there, a 25 volts capacitor is what you gonna need.
Electrolitic condensers also use to hold much more voltage than the plus 20 and minus 20 percent tollerance.... 83 volts units for sure will hold the job as they are tested, into the factories, receiving twice this voltage and monitored searching for dieletric current leakage.
Take care not to be obsessive about the old rule that you have to install condensers that can work with twice the supply voltage...not really needed and turns your project too much expensive... condensers turns too much expensive when voltage increases.... believe me... they can hold much more voltage than is written into their plastic covers.... of course!....because factories do not want complains.... so, as it is very difficult to build something with precise maximum voltage (electrolitic condenser is one of those cases) they design overdimensioned..... they build to hold 200 volts and because of safety reasons they write 83 volts into the plastic... this means "guaranteed into 83 volts operations accepting more 20 percent into surges of voltage"..... but not to have complains.... they buiding them to hold much more voltage...also the capacitance is bigger than the one written into the case....of course.. this is a good marketing.
Imagine someone measuring a 4700uf condenser and the measured result is 8000uf!!!...of course the one had bougth the unit will love that and will always buy this same brand.... as the guy will receive more microfarads by the same price!
Those big capacitors, the electrolitic units are used now a days to standard supplies only...no more used to critical applications where you need precision into the capacitance value...no more used as series output dc block condensers to amplifiers output....so.... factories giving you much more than the value written are just giving you a prize... much more by the same money... and this sells a lot!..... this is so effective that all brands are doing the same.... also about maximum allowable insulation voltage.
Carlos
voltage.... if rail voltage is 70... so you will need 150 volts and upper voltages.... not really needed enormous sized condensers as some 630 volts units are.
selecting capacitors into a voltage range that is twice the rail supply voltage, or rail to rail voltage is already an overkill.
In my home i use the same supply voltage..and i am doing this those last 48 years long and NEVER had any condenser or capacitor burned, with leakage or exploded.
If the 4N7 is the one near the zener diode into the input circuit... well... there you have not more than the zener voltage... any unit you find may fit.... there, a 25 volts capacitor is what you gonna need.
Electrolitic condensers also use to hold much more voltage than the plus 20 and minus 20 percent tollerance.... 83 volts units for sure will hold the job as they are tested, into the factories, receiving twice this voltage and monitored searching for dieletric current leakage.
Take care not to be obsessive about the old rule that you have to install condensers that can work with twice the supply voltage...not really needed and turns your project too much expensive... condensers turns too much expensive when voltage increases.... believe me... they can hold much more voltage than is written into their plastic covers.... of course!....because factories do not want complains.... so, as it is very difficult to build something with precise maximum voltage (electrolitic condenser is one of those cases) they design overdimensioned..... they build to hold 200 volts and because of safety reasons they write 83 volts into the plastic... this means "guaranteed into 83 volts operations accepting more 20 percent into surges of voltage"..... but not to have complains.... they buiding them to hold much more voltage...also the capacitance is bigger than the one written into the case....of course.. this is a good marketing.
Imagine someone measuring a 4700uf condenser and the measured result is 8000uf!!!...of course the one had bougth the unit will love that and will always buy this same brand.... as the guy will receive more microfarads by the same price!
Those big capacitors, the electrolitic units are used now a days to standard supplies only...no more used to critical applications where you need precision into the capacitance value...no more used as series output dc block condensers to amplifiers output....so.... factories giving you much more than the value written are just giving you a prize... much more by the same money... and this sells a lot!..... this is so effective that all brands are doing the same.... also about maximum allowable insulation voltage.
Carlos
Thanks Carlos for the information. Anyway, I already mounted the capacitors mentioned. This is the only available parts I have. I believe this will already serve. Haven't bought the electrolytic caps yet. Maybe on weekend. Maybe 10000uF/ 80volts only. The 100volt version could no be accommodated by the board. Another thing is that the 10000uF/100V caps are screw type and not solder types. Besides the power these caps will be handling are only 70volts. I just hope the power will not soar to more than 80volt in case of fluctuation. 
Julius
Julius
Of course factories have made condensers to accept voltage fluctuations
Try to imagine if a 70 volts condenser explode when powered with 77 volts!..... that factory will sell only the first day and will receive complains and will never sell condensers once again.
Voltage values printed are guaranteed super hiper safe value.... to allow that safety, they design the unit to twice this insulating voltage because industrial Engineers are not stupid... they do not want to loose their jobs.
Mains voltage variates plus and minus 20 percent.... so..... a 70 volts condenser HAVE to work till 84 volts...in the reality, they can hold almost twice the guaranteed voltage.
To be absolutelly sure a 70 volts condenser will hold exactly 70 volts they have to insert a 70 zener inside (ahaahahahah) or to test many insulator thicknesses till have one dieletric damaged with 70.001 volts...imagine how many units will be made and damaged just to give your that precision.... and the precision in this case is a big foolish... as voltages variates into the mains.
Having 70V into your supply rails you can use 70 volts condensers without fear..... if the one you installed explode them let me know because will be the first one i have the information that could not hold a surge of voltage.
Yes... i know that people suggest you to use higher voltage condensers... some of them will ask you to use twice the voltage...well... they are not paying the aditional cost for that.... i am sure they will ask to do that but in their own homes they use 70 volts condensers to 70 volts supply
Ahahahah... they will never admit that.... and i am sure they will be terrible lovers in their lives too... as they are so rigid, inside their non lubricated minds, that will go to the bed using socks... and worse... the crime of stupidity... having previously arranged the hour, the minute to start loving games with their wives... the ones they are just to loose...for sure.
Carlos
Try to imagine if a 70 volts condenser explode when powered with 77 volts!..... that factory will sell only the first day and will receive complains and will never sell condensers once again.
Voltage values printed are guaranteed super hiper safe value.... to allow that safety, they design the unit to twice this insulating voltage because industrial Engineers are not stupid... they do not want to loose their jobs.
Mains voltage variates plus and minus 20 percent.... so..... a 70 volts condenser HAVE to work till 84 volts...in the reality, they can hold almost twice the guaranteed voltage.
To be absolutelly sure a 70 volts condenser will hold exactly 70 volts they have to insert a 70 zener inside (ahaahahahah) or to test many insulator thicknesses till have one dieletric damaged with 70.001 volts...imagine how many units will be made and damaged just to give your that precision.... and the precision in this case is a big foolish... as voltages variates into the mains.
Having 70V into your supply rails you can use 70 volts condensers without fear..... if the one you installed explode them let me know because will be the first one i have the information that could not hold a surge of voltage.
Yes... i know that people suggest you to use higher voltage condensers... some of them will ask you to use twice the voltage...well... they are not paying the aditional cost for that.... i am sure they will ask to do that but in their own homes they use 70 volts condensers to 70 volts supply
Ahahahah... they will never admit that.... and i am sure they will be terrible lovers in their lives too... as they are so rigid, inside their non lubricated minds, that will go to the bed using socks... and worse... the crime of stupidity... having previously arranged the hour, the minute to start loving games with their wives... the ones they are just to loose...for sure.
Carlos
You are absolutely right about that. Ahahaha.... I can't imagine how big bucks i need to spend for it. Capacitor 10000uF/80V is about $6.5 while the 10000uF/100V would cost you about $10 a piece. Weird... Anyway, I believe 10000uF/80V i think will work then with about 50V AC, I can have about 65-70V DC output.
Yes.... relax and be happy.
enjoy your amplifier... and do not forget to post images....or to send images to me if do not want to post..... everything from you will be interesting, yourself, your condensers, your supply, your transformer, your bicicle, dog, ant, tree, family, parrot, mother in law, automobile, motorcicle, amplifiers, landscape and much more than that.
panzertoo@yahoo.com
Forum is International.... everything is different...so.... interesting!
regards,
Carlos
enjoy your amplifier... and do not forget to post images....or to send images to me if do not want to post..... everything from you will be interesting, yourself, your condensers, your supply, your transformer, your bicicle, dog, ant, tree, family, parrot, mother in law, automobile, motorcicle, amplifiers, landscape and much more than that.
panzertoo@yahoo.com
Forum is International.... everything is different...so.... interesting!
regards,
Carlos
a 230:50Vac 4% regulation transformer will give ~76Vdc when fed with 240Vac.
If the tolerance of the mains is +6%, then 254Vac will give ~80.5Vdc.
Yes, 80Vdc caps will survive in the short term. Many would not use caps this close to maximum rating. The higher leakage at ~ Vrating will make the caps run warmer than the ESR normally causes.
This will shorten their lifetimes.
If the tolerance of the mains is +6%, then 254Vac will give ~80.5Vdc.
Yes, 80Vdc caps will survive in the short term. Many would not use caps this close to maximum rating. The higher leakage at ~ Vrating will make the caps run warmer than the ESR normally causes.
This will shorten their lifetimes.
and the old amplifier i made with 8 transistors per channel. I got the design from an Electronic Enthusiast book. Sound good and clean but I'm sure this will be no match for the DX Turbo Amplifier. I can't wait to see these monster playing. I got 4 Targa 3-way speakers that I'm planning to put in a tower enclosure box. Each speakers has 150 watt ratings which will soon be dedicated for the DX Turbo.
Thanks to Carlos and the rest of DIY fanatics who made this amplifier possible.
Thanks to Carlos and the rest of DIY fanatics who made this amplifier possible.
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have the read my post?jlcastro77 said:
Do you understand all that is in it?
You need to consider exactly what the transformer will do.
You also need to know the normal mains supply voltage and the maximum mains supply voltage.
Then, you can make an informed decision.
It is not a case of blindly following good/bad advice.
Actually I don't have the transformer yet. I'll get one soon as the PSU board is completed. Correct me if I am wrong.
A 220V transformer with 50V AC output when connected to the PSU board will give you about 70V DC rating which is 4% rail from 50V AC out of the transformer. If I get a transformer with 45V AC out, then I might get about 63VDC output from the PSU board which is quite safer for the amplifier.
A 220V transformer with 50V AC output when connected to the PSU board will give you about 70V DC rating which is 4% rail from 50V AC out of the transformer. If I get a transformer with 45V AC out, then I might get about 63VDC output from the PSU board which is quite safer for the amplifier.
no.
A 220:50Vac transformer will only give 50Vac when fed with 220Vac and the secondary is loaded with resistors to draw exactly the power rating of the transformer.
If you feed 240Vac, you will get >50Vac.
If you run the secondaries open circuit, you will get >50Vac.
If you feed 240Vac +-6% then expect the secondary voltages to be all over the place.
Do the sums and then make the informed decision.
You should be asking; "what voltage range will a x% regulation transformer rated @ yVA and specified as z:50Vac give for a mains supply that varies from Avac to BVac and usually runs at CVac".
A 220:50Vac transformer will only give 50Vac when fed with 220Vac and the secondary is loaded with resistors to draw exactly the power rating of the transformer.
If you feed 240Vac, you will get >50Vac.
If you run the secondaries open circuit, you will get >50Vac.
If you feed 240Vac +-6% then expect the secondary voltages to be all over the place.
Do the sums and then make the informed decision.
this is where you went wrong.
You should be asking; "what voltage range will a x% regulation transformer rated @ yVA and specified as z:50Vac give for a mains supply that varies from Avac to BVac and usually runs at CVac".
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