On Apr 13, 8:32 am, (Scott Dorsey) wrote:
NoMoreSpam wrote:
wb5kcm wrote:
My Ranger is still every once in a while blowing the 5 amp primary
fuse when I switch it on. I have checked everything for a possible
intermittent short and everything checks good. The only thing I can
think of is inrush current. My Ranger has all the mods in the power
supply, solid state both HV and LV. The LV capacitor is 330 mfd and
the HV cap is 165 mfd. I did not suspect inrush current with the choke
input filters but I suspect with the solid state rectifiers and the
additional capacitor size this is possible? Does anyone have any
recommendations on a method to limit inrush? Also, does anyone know
what the nominal current consumption from the 115 VAC line with full
output/modulation for the Ranger? Any info is appreciated.
73, Randy

Very possible that the meter switch is intermittently arcing, causing the fuse
to blow. I ended up having to replace my meter switch, which cured the problem.

WHEN is the fuse blowing?

If it's blowing at times other than initial turn-on, it's not an inrush
current issue.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."- Hide quoted text -

- Show quoted text -

Hey Scott, once I turn on the Ranger it does not blow the fuse. Its
just every once in a while as soon as I move the switch it never turns
on and when I check the 5 amp fuse it will be blown. I am going to
install 1 or 2 Thermistors and give that a try and see how it goes.
Thanks for the input. 73, Randy

wb5kcm wrote:
Hey Scott, once I turn on the Ranger it does not blow the fuse. Its
just every once in a while as soon as I move the switch it never turns
on and when I check the 5 amp fuse it will be blown. I am going to
install 1 or 2 Thermistors and give that a try and see how it goes.
Thanks for the input. 73, Randy

Inrush current could be an issue. Adding a PTO thermistor is certainly
not a bad idea and probably should be done on every piece of equipment
out there with an expensive power transformer. Extends tube filament
life also.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."