W
w_tom
- Jan 1, 1970
- 0
Temporarily disconnect computer and ground cable. Measure
AC current from audio ground to that new safety ground wire.
Current should be on the order of less than 1 milliamp.
Unlike the experiment with safety ground wire, this test
actually reports something useful.
Of course that grounding cable will eliminate voltage. Wire
eliminating voltage tells us nothing useful. But is that
voltage created by a leakage that is too large or by a leakage
that is acceptable? You still have not answered a question
that determines whether a threat to computer, et al exists.
If your meter does not have an AC amperage option, then
connect audio ground to safety ground via a 10K ohm resistor.
If the leakage is 150 microamps, then AC voltage across that
resistor will be 1.5 volts. If the voltage is less, then the
leakage (and need for safety ground wire) is irrelevant. If
voltage across resistors is more, than your TV may be a threat
to computer and human life.
If leakage is less than 150 uamps, then even a wire about
the size of a human hair would have been sufficient to ground
out the leakage.
Again, more informative to know what that leakage is rather
than say when it does exist. And what you will learn by
actually measuring that leakage applies to human (and
transistor) safety with all other household appliances.
AC current from audio ground to that new safety ground wire.
Current should be on the order of less than 1 milliamp.
Unlike the experiment with safety ground wire, this test
actually reports something useful.
Of course that grounding cable will eliminate voltage. Wire
eliminating voltage tells us nothing useful. But is that
voltage created by a leakage that is too large or by a leakage
that is acceptable? You still have not answered a question
that determines whether a threat to computer, et al exists.
If your meter does not have an AC amperage option, then
connect audio ground to safety ground via a 10K ohm resistor.
If the leakage is 150 microamps, then AC voltage across that
resistor will be 1.5 volts. If the voltage is less, then the
leakage (and need for safety ground wire) is irrelevant. If
voltage across resistors is more, than your TV may be a threat
to computer and human life.
If leakage is less than 150 uamps, then even a wire about
the size of a human hair would have been sufficient to ground
out the leakage.
Again, more informative to know what that leakage is rather
than say when it does exist. And what you will learn by
actually measuring that leakage applies to human (and
transistor) safety with all other household appliances.
