Rev. 1.0
FMX30/FMX100/FMX250 User’s Manual
4—10
Input transformer is made up of two printed circuit boards. A four-turn primary
board is separated from a one-turn secondary by a thin dielectric film. Multiple
resisters provided damping. A trim pot sets the bias.
The output transformer has a one-turn primary on top of the circuit board and a
two-turn secondary underneath. Inductors provide power line filtering.
The AC power supply components, as well as the bridge rectifier and main filter
capacitor are mounted on the chassis. Switching in the power-entry module
configures the power transformer for 100, 120, 220, or 240 VAC; see Section 2.2,
Power Connections for switching and fuse information. A terminal strip with MOV
voltage-surge suppressors and in-rush current limiters is mounted on the chassis
between the power entry module and the toroidal power transformer.
The main energy-storage/filter capacitor, C1001, is located between the voltage and
power regulator boards. The DC voltage across the capacitor will be 45–55 volts
(FM30 and FM100) or 65–70 volts (FM250) when the carrier is on.
WARNING
Shock hazard!
Do not attempt to short the capacitor
terminals. A bleeder resistor will
discharge the capacitor in approx-
imately one minute after shutdown.
