POWER SUPPLY

TM 11-7025-233-23

2-6. POWER SUPPLY

Entering power passes through a line filter and the power switch, then goes

directly to the power supply circuit board containing all the other power supply

components. The power supply provides all voltages required by the teleprinter and

a power-ready signal for fault detection circuitry (fig. 2-2). All power supply

outputs go to the logic circuit board for control and for distribution to the

teleprinter components.

Power Supply

Figure 2-2.

The switching power supply is a universal type that can be configured with jumper

J2 for either nominal 117 V ac 60 Hz or 200 - 240 V ac 50 Hz international voltages

(para 4-61). Jumper J1, when cut or removed, must be replaced by a fuse in the F1

fuse clip. A fuse is installed in the F1 fuse clip in those locations where the

three-wire power source is terminated in a non-polarized outlet into which the

printer power cord is to be connected.

Jumper J2 is connected to the P4 plug on the board for nominal 117 V ac power and

is connected to P5 plug on the board for 200 - 240 V ac power sources.

WARNING

Line voltage is present at the line filter input

and output leads when the ac power switch is set

to OFF, and the teleprinter is still connected to

the ac line voltage source. Avoid contact.

CAUTION

When measuring voltage levels on the power board,

connect the common lead of the measuring device

to the Z bus on the board (fig D-1). Failure to

use this bus as the common will result in

improper reading of voltage levels on the board.

2-3