MFJ MFJ-4418, Instruction Manual

Page: 12 / 20

h. CURRENT LIMIT : This pull down box allows the current limit to be set from 5
to 30 Amps in 1 amp steps. This control works with the Electronic Fuse setting
and Slow blow time to select the current protection provided.
i. INPUT LOW LIMIT : This pull down box allows setting the absolute low level
of the input voltage from 9.5 to 13.0 volts in ½ volt steps. This limit is a hard stop
limit and the supply will turn off all output when the input is below this value for
more than 1/3 of a second.
j. ENABLE LOW LIMIT : This pull down box work in conjunction with the
“Enable on input at low limit” Check Box. This setting allows the input voltage
level to turn on the boost supply automatically when the input voltage falls below
this value. This setting can be from 10.5 to 13.0 volts in ½ volt steps. This is a
latching enable signal that will be cleared when the input voltage exceeds the
value set in the “Enable High Limit” setting. This hysteresis minimizes cycling
caused when the battery or other source is partially discharged and has higher
output impedance. Make sure the Enable High Limit is greater than the Enable
Low Limit.
k. ENABLE HIGH LIMIT: The limit where the MFJ-4418 will shut off the boost
supply when the input is above this setting. Used in conjunction with the “ Enable
on input at low limit
” Check Box. Make sure the “Enable High Limit” is greater
than the “Enable Low Limit”.
l. Electronic Fuse : This selects either fast or slow blow operation. In fast blow the
delay time is 1/10 second and in slow blow the delay time is adjustable by the
“Slow Blow Time” pull down box.
m. Enable on input at low limit : This setting allows the input voltage level to turn
on the boost supply automatically when the input voltage falls below the” Enable
Low Limit” value and off when the voltage exceeds the “Enable High Limit”.
n. Power Controlled By Ignition Lead : This checkbox enables the Ignition lead
sense functions.
o.
Ignition Hold Time
: This setting works with the “Ignition Turn Off Timer” and
“Power controlled by ignition lead” checkboxes. When the power is controlled by
the ignition lead and the “Ignition Turn Off Timer” checkbox is checked this
setting controls the hold on time after the ignition is turned off. This allows you to
complete a QSO without the fear of leaving the radio on as the MFJ-4418 will
turn off the output voltage at the end of this time unless the ignition is again
turned on.
p. Soft Start Enabled : Allow the power supply to pulse width control the charge
into the output capacitors minimizing the surge currents.
q. Audible Alarm On Low Voltage Enabled : Enables internal audible alarm on
low input voltage. The alarm always sounds on high current. When this is enabled
and power is removed from the MFJ-4418 the alarm may sound till the capacitors
discharge.
r.
Set Output Voltage
: Allows the output voltage to be adjusted up and down.