RT-202 - WHITE RODGERS - Datasheet.Live

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POWER TRANSFORMERS

Rectifier Transformers

All Primaries 117 Volts 50/60 Hz - Solder Lug Termination

Range of Output Resistive DIMENSIONS-INCHES

STANCOR Applied A.C. or Inductive Load Output Capacitive

PART Rectifier Volts Under Max. D.C. Load* Max D.C. Case Mounting Weight Agency

Sec. NUMBER Style Circuit Load (Approx.) (Volts) (Amps) (Volts) (Amps) H W D MW MD (lbs.) Certif.

A RT-201 NV C.T. 11.7 to 29.4 11.2 2.00 13.81 2.00 3.13 2.50 2.38 2.00 2.06 2.5 -

Bridge 11.1 to 28.5 23.0 1.25 30.02 1.25

RT-202 NV C.T. 12.0 to 29.8 11.1 4.00 14.73 4.00 3.50 2.81 2.75 2.25 2.28 3.8 -

Bridge 12.0 to 29.8 24.3 2.00 33.01 2.00

B RT-204 NV C.T. 11.7 to 29.2 12.0 8.00 14.54 8.00 3.88 3.13 3.88 2.50 2.72 6.1 -

Bridge 11.6 to 29.2 24.0 4.00 32.43 4.00

RT-206 NV C.T. 12.0 to 29.7 11.5 12.0 14.45 12.0 4.31 3.44 4.25 2.75 3.13 8.7 -

Bridge 12.0 to 29.7 24.0 6.00 32.06 6.00

C RT-208 NV C.T. 12.1 to 29.2 11.4 15.0 14.87 15.0 4.63 3.75 5.25 3.00 3.62 12.4 -

Bridge 12.1 to 29.2 23.7 8.00 32.54 8.00

D RT-402 NV C.T. 23.0 to 58.0 25.0 4.00 33.56 4.00 3.81 3.13 4.50 2.50 2.72 6.9 -

Bridge 23.0 to 58.0 51.5 2.00 72.59 2.00

RT-408 NV C.T. 25.0 to 54.1 23.4 12.0 32.04 12.0 5.41 4.38 6.75 3.50 5.25 26.5 -

Bridge 25.0 to 54.1 46.3 8.00 66.84 8.00

* Indicates Filter Capacitor Size: 1 = 1000 MFD, 2 = 500 MFD, 3 = 2000 MFD,

4 = 4000 MFD, 5 = 6000 MFD, 6 = 3000 MFD,

7 = 7500 MFD, 8 = 12000 MFD, 9 = 15000 MFD

Each transformer has the winding arrangement and terminal numbering

shown in the schematic diagrams. The primary windings may be used in series

to raise or lower the secondary voltage output. A variety of combinations is

possible using the taps on both windings for “Aiding” or “Bucking” action.

Designed for 117 V, 50/60 cycle operation; however, may be satisfactorily

operated at 400 cycles.

The secondary winding of each transformer consists of two identical

windings connected to terminals 8 & 9 and to 10 & 11 respectively. Use the

tables showing the various output voltages for specific terminal connections

as your guide. Many combinations are possible other than those listed in the

tables. All ratings shown are for normal convection air cooled applications.

Select only rectifiers capable of handling the voltages and currents described.

When operating these transformers continuously at maximum rated output

voltage and current and because of certain other conditions, it is sometimes

necessary to derate the rectified output current (D.C.) as much as 20%, in

order to stay within the recommended operating temperature limit of 105

degrees Centigrade. The type of rectifier circuit and load (capacitive, inductive,

or resistive) determines the relative amount of current (RMS) in the transformer

secondary winding. The relationship of A.C. to D.C. (secondary RMS current

to rectified D.C. output) for typical circuits and loads is given in the technical

data on page 7 of this section. Operating duty cycle, type of cooling (natural

convection in free air or otherwise) and the power line input voltage and

frequency also have an effect on the transformer temperature. These things

should all be properly related to the results in any specific application.

The “RT-Series” of transformers may also be used in rectifier circuits

other than the Full-wave C.T. and Full-wave Bridge. In circuits such as the

Half-wave or Full-wave Voltage Doubler (symmetrical) and Full-wave Bridge,

where a C.T. connection is not required, both secondary windings may be

connected in parallel, to double the RMS current that is available from each

secondary separately. The RMS voltage will, of course, be half of the amount

available as that obtained with the secondaries connected in the series.

Please refer to page 7 of this section to obtain the secondary RMS current as

related to each rectifier circuit and type of load.

Voltages expressed in the tables are approximate and will vary within plus

or minus two (2) Volts.

For Terminal Connection Data refer to pages 8-10.

For outline drawings refer to page 12.

––Rectifiers not included

Style NV with lugs

POWER TRANSFORMERS

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Rectifier Transformers - Terminal Connection Data

How to Determine Secondary AC (RMS)

Current Ratings

The tabular data for the various Rectifier, Control and Filament types

of transformers listed in this catalog shows A.C. (RMS) secondary cur-

rent, unless otherwise indicated as in the “RT” series listings.

When used in various rectifier circuits, with the possibility of differ-

ent types of loads, the RMS secondary current will be different for each

specific condition. To assist the user, the following information is given

so that the proper transformer may be selected.

The rectifier circuits as related to these transformers are:

HW = Half-Wave

FWCT = Full-Wave Center Tap

FWB = Full-Wave Bridge

FWD = Full-Wave Doubler

The formula for the relation between secondary RMS current (I

)

which the transformer has to deliver and the D.C. output current taken

from the rectifier (I

) is: I

= K

x I

where K

is the form factor.

The factor for each circuit and type of load is as follows:

REACTOR LOAD CAPACITOR LOAD

Form Factor Rectifier Circuit Form Factor Rectifier Circuit

1.25 HW 2.3 HW

0.7 FWCT 1.2 FWCT

1.0 FWB 1.8 FWB

4.0 (approx.) FWD

Only transformers with a CT connection are usable in the FWCT

circuit and the FWD circuit will have only a capacitor load. The size and

type of capacitors used in the FWD circuit will affect the form factor. The

factor shown is an approximate maximum for the full-wave symmetrical

voltage doubler circuit using two similar electrolytic capacitors.

The transformer selected for a specific D.C. output voltage and

current rating, with known type of load after the rectifier, should deliver

sufficient RMS voltage to make up for the voltage drop in each

rectifier junction plus any drop in a filter or regulator that is used.

fwct

fwb

fwd

TECH TIP

Bucking/Aiding Coils

A “Buck-Boost” or “Bucking-Aiding” winding is a separate winding that

when connected in the same rotation as the main winding adds the turns of

the Buck-Boost winding to the turns of the main winding. If the Buck-Boost

is connected in opposition to the main winding, it is equivalent to removing

turns from the main winding.