Power Supply PP-3514/U, block diagram.
of the transformer for 115-volt ac op-
f. SHORT CIRCUIT CURRENT MA Switch
S2. SHORT CIRCUIT CURRENT MA switch
eration and are connected to trans-
S2 limits the output current to the indicated
former terminals 1 and 6, and 2 and
maximum by selecting the resistance that ap-
7. One jumper is used for 230-volt ac
plies the correct value of sensing voltage to
operation and is connected to trans-
the circuit for operation at the load current
former terminals 2 and 6. Alternat-
selected.
ing-current power is applied to the
g. METER RANGE Switch S3.
METER
primary
windings,
transformer
RANGE switch S3 selects the meter range to
through fuse F1 and front panel
dicate the dc voltage or current supplied to
switch S1, when S1 is set to the ON
the load.
position. The ON indicator light, DS1,
is connected in series with current-
1-4. Power Supply Stage Analysis
limiting resistor R1 across one of the
transformer primary windings, and
lights red when switch S1 is set to
a. General. The power supply converts 115
the ON position.
or 230 volts ac to a regulated dc output of 0 to
30 volts. The current output from the power
(2) The transformer secondary consists
supply is 0 to 150 milliamperes (ma), regu-
of two windings; one winding sup-
lated. Front panel controls adjust the voltage
plies ac power to the main power
and current outputs to the desired levels. The
supply, and the other winding sup-
panel meter, M1, measures the output voltage
plies ac power to the auxiliary pow-
or current.
er supply. Both secondary windings
are center tapped.
b. Transformer.
(1) The transformer T1 primary is com-
c. Main Power Supply. The ac voltage from
posed of two windings connected in
transformer terminals 3, 4, and 5 is rectified
parallel for 115 volts ac input or in
by diodes CR1 and CR2, and filtered by capa-
series for 230 volts ac input. T w o
citor C2. The rf bypass capacitor, C1, connect-
jumpers are used on the primary side
ed across transformer terminals 3 and 5, elim-
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