JPR: But remember Energy is the factor of Current, Voltage, and Time. From a protection stand-point, TVS components divert currents and clamp voltages. It is for this reason that they are used in the circuit, system. Of course for best results lower clamping voltage is desired. If the current is the same and the waveform the same, the voltage for a TVS diode is lower the energy is also lower, but who cares at least the circuit/system is protected. Dave
-----Original Message----- From: j...@aol.com [mailto:j...@aol.com] Sent: Wednesday, June 19, 2002 11:08 AM To: hutch...@protek-tvs.com; robert_wil...@tirsys.com; mpet...@analogic.com; emc-p...@majordomo.ieee.org Subject: Re: Transient Voltage Suppressor - Europe approvals? In a message dated 6/19/2002, Dave Hutchins writes: Energy has nothing to do with the capability of the TVS device. It is also proven that the energy in the transient threat is not the energy dissipated in the TVS component, just ask any old timer even those at Harris. Hi Dave: I'm not sure I agree with you on this one, but perhaps the issue is simply one of semantics. The "energy" I referred to was the energy in the surge, not the protection device. For example, a gas tube can handle, without damage, surges of far higher energy than a Transzorb. If I recall correctly, MOVs can also typically handle surges of higher energy than a Transzorb. In the past, when I have used a Transzorb or comparable device, it was for tertiary protection inside a circuit that was already protected by other devices with the ability to handle much higher energy surges. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. 781-721-2848 http://www.randolph-telecom.com
