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clarifcation of capacitor values
- Thread starter tinkerman
- Start date
What I see in your image reflects uF (micro Farad). Using .002 uF as an example that would be 2 nF (nano-Farad) micro or u being negative sixth and nano or n being negative nineth power of ten. .001 uF = 1 nF = 1000 pF, .06 uF = 60 nF = 60,000 pF and .02 uF = 20 nF = 20000 pF.
So above we have Micro-Farad, nano-Farad and pico=Farad conversions.
Ron
So above we have Micro-Farad, nano-Farad and pico=Farad conversions.
Ron
Thank you. Thought I was on the right track. What puzzled is the sizes. Those are very small capacitors. Mind you the technology 45-50 years ago was quite different. There have been a number of failures. Couldn’t they be replaced with modern types that are much more durable?
Where do you see them labeled as mf?
The picture you show has them labeled μF. It is common to see μF labeled as uF or as mmF (milli-milli Farad). I have seen mF in old, old diagrams where it meant microfarad, but that's pretty rare.
1 nF = 0.001 μF, so 2 nF = 0.002 μF, 20 nF = 0.02 μF, and 60 nF = 0.06 μF
Probably. You want to use the same type and a voltage rating at least as great as a minimum. Depending on just what these things are doing in the circuit, other parameters may also be important such as temperature coefficient, leakage current, ESR, self-resonant frequency, and others. It's also possible that they are very non-critical and anything that is within a factor of two or perhaps even ten will work. The devil's in the details.
Hello,
Looking at the arrangement of the capacitors, they are used for RFI/EMI suppression on the mains.
You will need class X and Y capacitors for them:
Class X and Class Y capacitors
Many safety regulations mandate that Class X or Class Y capacitors must be used whenever a "fail-to-short-circuit" could put humans in danger, to guarantee galvanic isolation even when the capacitor fails.
Lightning strikes and other sources cause high voltage surges in mains power. Safety capacitors protect humans and devices from high voltage surges by shunting the surge energy to ground.[30]
In particular, safety regulations mandate a particular arrangement of Class X and Class Y mains filtering capacitors. [31]
In principle, any dielectric could be used to build Class X and Class Y capacitors; perhaps by including an internal fuse to improve safety.[32][33][34][35] In practice, capacitors that meet Class X and Class Y specifications are typically ceramic RFI/EMI suppression capacitors or plastic film RFI/EMI suppression capacitors.
This comes from the wiki about capacitors:
https://en.wikipedia.org/wiki/Capacitor_types
Bertus
Looking at the arrangement of the capacitors, they are used for RFI/EMI suppression on the mains.
You will need class X and Y capacitors for them:
Class X and Class Y capacitors
Many safety regulations mandate that Class X or Class Y capacitors must be used whenever a "fail-to-short-circuit" could put humans in danger, to guarantee galvanic isolation even when the capacitor fails.
Lightning strikes and other sources cause high voltage surges in mains power. Safety capacitors protect humans and devices from high voltage surges by shunting the surge energy to ground.[30]
In particular, safety regulations mandate a particular arrangement of Class X and Class Y mains filtering capacitors. [31]
In principle, any dielectric could be used to build Class X and Class Y capacitors; perhaps by including an internal fuse to improve safety.[32][33][34][35] In practice, capacitors that meet Class X and Class Y specifications are typically ceramic RFI/EMI suppression capacitors or plastic film RFI/EMI suppression capacitors.
This comes from the wiki about capacitors:
https://en.wikipedia.org/wiki/Capacitor_types
Bertus
