[AMPS] Re: Power Handling of Resistors
Jon Ogden
jono@enteract.com
Thu, 09 Mar 2000 22:44:49 -0600
on 3/9/00 9:36 PM, Carl Clawson at cclawson@transport.com wrote:
>> Yet 256 Joules will destroy a tank circuit according to what you say.
>
> It takes about 500 J to melt a gram of brass from room temperature. I think
> 256 would be enough to seriously damage a band switch. The unresolved
> problem isn't the available energy, it's how it gets to the switch.
Let's do the math:
A Joule is 1 Watt-second. Multiply watts times seconds. If I am
transmitting at 1500 Watts for 10 seconds, the total energy passing through
the switch is 15,000 joules.
So if I can pass 1500 watts safely through the bandswitch for 10 seconds (or
rather an indefinite period of time) then how would 250 Joules destroy it?
I don't doubt that it takes 500 Joules to melt brass. But for how long a
period of time does one need to apply the energy to make it melt?
Perhaps I am incorrect in my understanding of the term "Joule" but when I
looked it up, it is by definition a watt-second.
Enlighten me.
73,
Jon
KE9NA
-------------------------------------
Jon Ogden
KE9NA
Member: ARRL, AMSAT, DXCC, NRA
http://www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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