[Amps] (no subject)

Dan dpipes at earthlink.net
Sun Dec 26 14:45:32 EST 2004


 Hal,
and others .. again thanks for the info. I do believe I need to run two more separate circuits to the shack a 220 and 110 line fromt he breaker box. However in reading the info about inrush currents is this what the Ameritron ICP-120 )or 240) does? Here is what their site says and any opinions on the Ameritron device??
from their web site:
 
When you first turn on your amplifier, a massive inrush current gushes in. Your house lights flicker as you hear loud "thump" from your amplifier. This terrible inrush current stresses all your power supply components to their limits. Your cold tube filament suffers abusive thermal shock.
Eventually, this massive inrush current will damage your amplifier.
Ameritron's Step-Start Inrush Current Protector stops damaging inrush current. By starting your linear amplifier through a high power current limiting resistor and then shorting the resistor with a relay, you get a start up sequence that's easy on your tube and power supply components.
Now you can add this protection to your amplifier without complicated wiring -- you don't even have to take the cover off. Simply plug your amplifier power cord into the Ameritron Inrush Current Protector. By limiting heavy inrush current to safe low level, you'll get a longer lasting amplifier. You might avoid replacing expensive tubes and components. Avoiding just one repair job could pay for this extended protection.
Momentary high-voltage "spikes" in the ac line can also cause damage to your amplifier. The Ameritron Inrush Current Protectors have built-in varistors to absorb these spikes before they can cause damage. Works with nearly all linear amplifiers. Ameritron ICP-120, $79.00, for 120 volt wired amplifiers. Limits current to 12 amperes during heavy draw inrush period. 20 amperes continuous operating current.
*********** REPLY SEPARATOR ***********
 Dear Sir,

One phenomenon that may be occurring is the in-rush current
to the amplifier is very heavy. This is exacerbated by low line
voltage.

Using a delay timer and DPDT relay with some resistance
switching in and out of the transformer primary for just a
few seconds will allow the HV capacitors to charge slowly,
reducing the amperage drawn by the filter, and would also
allow the tube filaments to also draw current slowly by
limiting the amperage in the primary winding.

Mr. Rich Measures, AG6K, on his website, 
SOMIS.ORG, lists a very reliable and affordable
scheme for step-starting that would prevent further
mishaps.

Sincerely,
Hal Mandel
W4HBM



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