i have one transformer 74-0-74 volt output.what is the voltage of capacitors i have to by after bridge rectifier.the old ones are 4700mf 125v.is very difficult to find 125v.only 100volts are available.is ok?
If this is full wave rectified, a 74 volt transformer winding will give you 74 * 1.414 - diode drop of 1.4V, so around 104V raw dc. You want to allow for overvoltage on your mains, etc. so 100V would be inadequate. I would be looking for 150Vdc at a minimum. You don't mention what the form factor of the existing capacitors is, whether snap in, screw terminal, etc. I would try to be reasonable in terms of physical characteristics, how they mount, etc. in selecting a replacement.
Not sure who your normal suppliers are, but digikey has a few available:
https://www.digikey.com/en/products...gAvqXi0U0EHwEjxU2fOWrSCgQDUQpALajhAsAFY46tWqA
Not sure who your normal suppliers are, but digikey has a few available:
https://www.digikey.com/en/products...gAvqXi0U0EHwEjxU2fOWrSCgQDUQpALajhAsAFY46tWqA
Or you could parallel 2 X 2.200µF of a higher voltage,
or another combination to get the desired capacitance.
Hugo
or another combination to get the desired capacitance.
Hugo
Forgot to mention:
Careful, you will be dealing with something like 210VDC. Make it a solid build 🙂
Hugo
Careful, you will be dealing with something like 210VDC. Make it a solid build 🙂
Hugo
i have found 3300mf 100v i replace the 4 old ones with slight bigger in mf and order 8 caps.space is enough to stack all 8
100V caps are really not enough...
By paralleling two 3.300µF caps you obtain 6.600µF but the voltage doesn't double, it remains only 100V.
Hugo
By paralleling two 3.300µF caps you obtain 6.600µF but the voltage doesn't double, it remains only 100V.
Hugo
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