RE: Static Discharge
The 2kv cap is not suppose to leak.
Assuming that the energy level develops on low capacitance value (few
nano-farads), than a "bleed" resistor located between the positive and the
negative feeding lines of 10 to 100K can discharge it (lower value - better
Better way is to clamp the voltage developed from excessive charges by using
low impedance path that activated at a certain voltage that fits
the system requirements at normal working conditions.
Chief R&D Engineer
> PowerDsine Ltd. - Powering Converged Networks
> 1 Hanagar St., P.O. Box 7220
> Neve Ne'eman Industrial Zone
> Hod Hasharon 45421, Israel
Tel: +972-9-775-5100, Cell: +972-54-893019
> E-mail: <mailto:yaird@xxxxxxxxxxxxxx>.
> -----Original Message-----
> From: Dieter Knollman [SMTP:djhk@xxxxxxxxxx]
> Sent: ו, ספטמבר 15, 2000 6:53 PM
> To: stds-802-3-pwrviamdi@xxxxxxxx
> Subject: Static Discharge
> My background is telephony. I'm totally new to 802.3, so please excuse
> my ignorance.
> One thing that appears strange is the lack of an intentional discharge
> path for the potential on the cable.
> The only means that I have found is breakdown of the common mode
> termination capacitors.
> Are these caps with 2 kV rating intended to be leaky?
> On POTS line interfaces the Tip lead is typically biased around ground
> and serves as a discharge path to earth ground for Analog Sets. Do the
> IP Phones require a discharge path via the LAN?
> Dieter Knollman