mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
When it comes to lightning protection, and to a lesser degree 60Hz impedance, which is better when compared based on the same gauges?
Braided.
Braided is used to connect the air terminals and for the downleaders in a lightning protection system.
But what or how does the braiding do to reduce the impedance?
When it comes to lightning protection, and to a lesser degree 60Hz impedance, which is better when compared based on the same gauges?
Lightning is not a DC or 60 Hz event, it has components in the MHz so skin effect is a factor. I'll also suggest that the braided cable used for downcomers is much easier to install than the equivalent normally stranded copper.
But how can it be a MHz event when it is in fact a brief DC flow? (I have a theory {similar to a DC transmission displaying capacitance and inductance when first energized} , but want to hear an unbiased take)
But how can it be a MHz event when it is in fact a brief DC flow? (I have a theory {similar to a DC transmission displaying capacitance and inductance when first energized} , but want to hear an unbiased take)
It also has a very sharp leading edge, and if there is too much inductance in the wire a substantial enough voltage can be developed to cause arcs to other paths.It's pulsating DC and it pulsates at around 100 MHZ. The pulses are thought to be caused by the breakdown and re-establishment of ionized air in the strike path.
There can actually be moments of reverse current flow in a strike, as well a "ripple" at very high frequency.
The driving voltage is DC, but the current is affected by sudden changed in path impdedance caused by ionization and the inductance of the "wire" when subject to sudden enormous currents.
It's pulsating DC and it pulsates at around 100 MHZ. The pulses are thought to be caused by the breakdown and re-establishment of ionized air in the strike path.
Like an HID lamp have a non sine wave arc?
The capacitor across the points insures that the spark is actually AC with a DC bias. The coil secondary is grounded at one end.I am not sure about that, but if you are asking how DC can behave like AC, the best example I can give is an automobile ignition system. The coil has pulsating 12 VDC on one side, and 10-30 kV coming out the other, but is also pulsating DC, but with a high enough voltage to make a spark. The frequency is dependent on the RPM of the engine.
Lighting is a bigger spark at hundreds of millions of volts, but still pulsating DC.
The capacitor across the points insures that the spark is actually AC with a DC bias. The coil secondary is grounded at one end.
You can if the DC bias is close to 1/2 the peak to peak AC.Points? Capacitors? That's so last millennium.
No, the spark is not AC. If it were, we would not distinguish the anode from the electrode in a spark plug.