Hi
Another question I need help on, I am trying to protect
AM transmitter circuitry from all paths ( + Rail , Ground and RF outputs ) the classic solutions are spark gaps for RF antenna outputs, fuses inductance and regulation
for DC rails - but what about ground itself?
Given a DC rail of 240v (DC) and
10 amps of current ie 2400w what generally is the
current at the ground point. Is it 10amps for that
device or more? if its more how can it be more ?
A bridge rectifier arranged as to block voltage/current
arising in ground itself ie + and - are joined together
and are tied to actual ground - then the AC Poles
form ground inputs i understand will offer a measure of protection.
I have built a number of these ground diode switching
rectifiers and have had total success to date.
Has anyone had similar success?
Thanks / Chris
Another question I need help on, I am trying to protect
AM transmitter circuitry from all paths ( + Rail , Ground and RF outputs ) the classic solutions are spark gaps for RF antenna outputs, fuses inductance and regulation
for DC rails - but what about ground itself?
Given a DC rail of 240v (DC) and
10 amps of current ie 2400w what generally is the
current at the ground point. Is it 10amps for that
device or more? if its more how can it be more ?
A bridge rectifier arranged as to block voltage/current
arising in ground itself ie + and - are joined together
and are tied to actual ground - then the AC Poles
form ground inputs i understand will offer a measure of protection.
I have built a number of these ground diode switching
rectifiers and have had total success to date.
Has anyone had similar success?
Thanks / Chris
All currents going into and out of any point must sum.
Something is wrong if its more than 0 on your safety ground. RF ground is another story.
Ground should be at ground potential, do you have rocky soil? This can be big problem for antennae ground, sometimes a counterpoise can be used instead.
Why do you need to protect from ground?😕
Something is wrong if its more than 0 on your safety ground. RF ground is another story.
Ground should be at ground potential, do you have rocky soil? This can be big problem for antennae ground, sometimes a counterpoise can be used instead.
Why do you need to protect from ground?😕
I agree 0v should be just that
There are occurances though of lightning travelling through ground to re-emerge. A recent one found people camping and lightning coming up from the ground inside their tent
Telcommunications infrastructure also finds MOV's /other
protection near buried cables.
A bridge rectifier so arranged offers a modest amount of protection from currents /voltages on ground itself.
Cheers
There are occurances though of lightning travelling through ground to re-emerge. A recent one found people camping and lightning coming up from the ground inside their tent
Telcommunications infrastructure also finds MOV's /other
protection near buried cables.
A bridge rectifier so arranged offers a modest amount of protection from currents /voltages on ground itself.
Cheers
Protecting from such faults can be extremely expensive as I recall. The problem is that you dont want the system to interfere with safety and performance of the ground in its operation for the normal faults. It might well work, but you may have liability issues if the system does not comply with code (or local interpretation thereof).
Having a good grounding system overall should help, ei more than 1 rod. Some places also have connection to building rebar etc. Real ground circuit impedance tends to be rather more than 0, much more. The tent incident could not happen otherwise. As lightning could be described as one monster square wave, keeping lead inductance down should help.
An elaborate antennae ground will help its performance anyhow.
Having a good grounding system overall should help, ei more than 1 rod. Some places also have connection to building rebar etc. Real ground circuit impedance tends to be rather more than 0, much more. The tent incident could not happen otherwise. As lightning could be described as one monster square wave, keeping lead inductance down should help.
An elaborate antennae ground will help its performance anyhow.
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