[Heath] IP-28 Issues

[Gary H. Harmon, Jr.]

A engineering friend of mine locally has been working hard to resolve issues
with an IP-28 power supply.  His findings follow:

 

"I have come to the conclusion that the circuit design on the IP-28 has some
serious issues with the power rating of the current limit pot.  All power
must flow through this series device and power dissipation of the pot would
be around 30W at full voltage.  The ten turn pot is only rated at 2W.  I
honestly do not know what the Heath engineers were thinking when they
designed this one!  I would suspect that other components in the load
current path are also under rated; I know my unit took out three transistors
in addition to the pot and another series resistor."

 

Any thoughts on this problem?

 

Vr,

 

Gary H. Harmon, Jr. - K5JWK

6003 Archwood

San Antonio, TX 78239-1504

210.657.1549h / 210.884.6926c/t

 

"Retirement means every day is a Saturday except Sunday"

http://www.grissomroadcoc.org

 

 

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