On Apr 13, 8:27 am, Chuck Harris wrote:
wb5kcm wrote:
Thanks for the info Harold. I think that is the way I want to go is
with the ICL Thermistor or Varistor. The only thing I need is to find
out which one to use. Looking at them in the catalog, it seems the
deciding factor will be the maximum sustained current from the Ranger.
If I need a 4 amp Thermistor then it may only provide about 10 ohms

A better way is to take a relay and connect its coil, through a selected
resistor, to one of the low voltage supplies. The relay's NO contacts
should be put in series with the power line, and should have a 5 or 10 ohm
power resistor across them.

When the power is switched on, the 5 or 10 ohm resistor will be in series
with the power line, and the power supply will start to charge the filter
capacitors. When the filter capacitor's DC gets to a high enough value,
the relay will close, and apply full mains power to the primary.

This circuit has two inherent flaws: 1) if the filters get leaky, they
might never charge up enough to close the relay, and the power resistor
will overheat, and 2) the relay will draw current from your power supply.

-Chuck

Chuck, interesting idea using the relay. I will keep your message. I
am going to try the Thermistor and see if that will do the trick. The
concern I have with the Thermistor is if it will handle the current
that the Ranger draws and if it may cause poor regulation in the AC
side. I am going today and pickup a couple of the CL-90 Thermistors
and give them a try. I will report back possibly SUnday with the
results. If the Thermistor doesnt work, I may build up something like
your relay idea into an external metal box and use this. 73, Randy