!). Would act as a protection fuse to save the PC board from massive destruction in the case of the ground of the attached component becoming hot to the mains.
2). Would help reduce magnetically induced hum in the unbalanced signal conductor along the length of the shield in the interconnecting coaxial cable resulting from any AC mains current flowing as a result of voltage differential in the earth of the chassis of various system components.
3). In extreme cases will inspire a user who is not as brain dead as most, to think about it's purpose and perhaps even ask others "Why?"
2). Would help reduce magnetically induced hum in the unbalanced signal conductor along the length of the shield in the interconnecting coaxial cable resulting from any AC mains current flowing as a result of voltage differential in the earth of the chassis of various system components.
3). In extreme cases will inspire a user who is not as brain dead as most, to think about it's purpose and perhaps even ask others "Why?"
rcavictim said:!). Would act as a protection fuse to save the PC board from massive destruction in the case of the ground of the attached component becoming hot to the mains.
2). Would help reduce magnetically induced hum in the unbalanced signal conductor along the length of the shield in the interconnecting coaxial cable resulting from any AC mains current flowing as a result of voltage differential in the earth of the chassis of various system components.
3). In extreme cases will inspire a user who is not as brain dead as most, to think about it's purpose and perhaps even ask others "Why?"
I feel rather stupid asking this, but what exactly is a star ground? I'm familiar with the signal ground and power ground, but not the star ground.
Also, if I'm not mistaken, the speaker ground is connected to power ground, yes?
It might make more sense the call it asterisk ground rather than star ground. It is the practice of bringing ALL ground connections to a single physical point.like a lug or a terminal. All ground connections "lead out" in a star configuration to the individual circuits.
It is done to prevent the small resistances and inductances in the ground connections from cross coupling (talking to each other). To see the problem more clearly; take a schematic and replace every ground connection with a small resistor... see what a mess things became??
It's not so hard to do but often misunderstood... post a schematic and people can tell you how to do the "star"
It is done to prevent the small resistances and inductances in the ground connections from cross coupling (talking to each other). To see the problem more clearly; take a schematic and replace every ground connection with a small resistor... see what a mess things became??
It's not so hard to do but often misunderstood... post a schematic and people can tell you how to do the "star"
You can clearly see the "star" at this picture of one of mine boards, http://www.leetmaa.se/diy/PICT0503.JPG
Stephen Morgan said:
Hmmm... and what is the root of the word asterisk? Hint: it's also in astronomy and disaster.
Besides J.P. Morgan didn't Tesla get some funding from a dude named "aster" representing considerable "risk"? Spelling stretch notwithstanding to promote joke value.
The connection to a good ground was well appreciated by Tesla BTW.
dfdye,
I use grounds planes all the time and then star them together at single point. Ground planes are not always good things. They can be handy shields, and they can control impedance for high speed stuff, but they can also be awesome couplers (un-wanted) as well.
So in the spirit of jneutronesque analosity, they should be applied thoughtfully... ground is a myth.
I use grounds planes all the time and then star them together at single point. Ground planes are not always good things. They can be handy shields, and they can control impedance for high speed stuff, but they can also be awesome couplers (un-wanted) as well.
So in the spirit of jneutronesque analosity, they should be applied thoughtfully... ground is a myth.
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