Jason Hsu wrote:
|| It's part of a design for a T/R sense circuit for a noise
|| cancellation device.
||
|| I won't bore you with too many details. One thing I noticed in a
|| design I'm looking at is that 1W resistors could be subject to as
|| much as 50W of power apiece during the time it takes for a relay to
|| respond. This response time is 7msec. The overall duty cycle will
|| be low (well under 1%).
||
|| Can the 1W-51 ohm resistors handle this 50 RF volts 0-peak (about 50W
|| PEP) for .007 sec? 50W over .007 seconds is .35 Joules. .35W for 1
|| second is also .35 Joules, which a 1W resistor should have no trouble
|| handling. Can the resistors be damaged during that .007 seconds?
||
|| Also, how much time does it take to damage a toroid? If it can
|| handle X units of flux density continuously, how much flux density
|| can it handle for .007 seconds with a low overall duty cycle (like
|| well under 1%)?
||
|| Jason Hsu, AG4DG
|| usenet AAAAATTTTT jasonhsu.com

I have here some datasheets of Beyschlag MELF-resistors (CMA0204). They take
up to 40W continuous pulses if the pulse length is 200us or shorter. So 2-3
of those should be able to absorb your pulse. They also have non-inductive
types for RF-apps.
--
ciao Ban