Transformer T1 Circuits.

TM 11-6130-227-40

b. Transformer T1 Circuits. Transformer T1 has a

s o l e n o i d relays K2-K6 (K1-K5) which are energized

i n various combinations, depending on the position

m u l t i p l e - t a p p e d primary winding and two separate,

of BATTERY VOLTS switch S2. The 6-volt dc

identical,

center-tapped

secondard windings.

Primary taps 1, 2,3, and 4 are connected to contacts

required to energize the coils of the relays is taken

3 , 4, 5, and 6, respectively, of CHARGE SWITCH

from legs B and C of rectifier CR2.

S1. Thus the setting of CHARGE SWITCH S1

(1) 6 - v o l t c h a r g i n g . W h e n

BATTERY

VOLTS

determines the number of effective turns of the

switch S2 is in the 6 position, relays K2-K6(K1-K5)

primary winding of transformer T1 and con-

are energized. The energizing circuit is from center

sequently the voltage and current of the outputs of

t a p 10 of winding 9-11 of transformer T1, through

the two secondary windings. This arrangement

BATTERY VOLTS switch S2 in the 6 position,

p r o v i d e s a range of transformer outputs that per-

through the coils of relays K2(1) and K6(K5) in

mits the selection of a high, medium, or low

parallel, through normally closed contacts. 3-4 of

c h a r g i n g rate (c below). Blower motor B1 is con-

r e l a y K1(K6), to the Negative (--) terminal of rec-

nected across the ac input between contact 5 of

tifier CR2. When relays K2(K1) and K6(K5) are

CHARGE SWITCH S1 and terminal 5 of the

operated, two parallel circuits, using legs B and C of

primary winding of transformer T1. The primary

rectifier CR1 and legs A and D of rectifier CR2 as a

winding of transformer T1 acts as an autotrans-

f u l l - w a v e , center-tap rectifier, are established. This

f o r m e r so that the voltage applied to blower motor

arrangement produces a dc output of approximately

6 . 5 volts at 75 amperes maximum. One circuit is

B 1 increases as CHARGE SWITCH S1 is advanced

LOW to MED to HIGH and consequently the

from center tap 7 of winding 6-8 of transformer T1,

s p e e d of blower motor B1 increases proportionally.

through contacts 4-3 of relay K6(K5) through

Thus, a larger amount of cooling air is drawn in and

a m m e t e r M2 to positive (+) battery connector P3,

e x p e l l e d by the blower as the charging rate is in-

through circuit breaker CB2 to the negative ()

creased.

b a t t e r y connector P2, and through circuit breaker

c. Rectifier Circuits.

Transformer T1 has two

C B 2 to the negative terminal of rectifier CR1. The

separate,

identical secondary windings whose

o t h e r "circuit is from the positive (+) terminal of

output voltage is controlled by the position of

rectifier CR2, through circuit breaker CB3 and

C H A R G E S W I T C H S 1 (b a b o v e ) . T h e o u t p u t o f

ammeter M2 to positive battery connector P3,

secondary winding 6-8 is connected to rectifier CR1,

through

the

battery

under

charge

negative

a n d the output of secondary winding 9-11 is con-

b a t t e r y connector P2, through contacts 4-3 of relay

nected to rectifier CR2. Each rectifier is a full-wave,

K 2 ( K 1 ) , to center tap 10 of winding 9-11 of trans-

bridge

rectifier;

this

arrangement

provides

two

former T1. The coil of relay K1(K6) is connected

s e p a r a t e full-wave rectifier circuits. Each rectifier

d i r e c t l y across the dc output of the rectifiers and

circuit has a maximum output of approximately

controls the operation of relays K2(K1) and K6(K5).

1 2 . 6 volts at 40 amperes. These outputs are con-

Relay K1(K6) will operate (open its contacts) when a

nected to five solenoid relays K2-K6 (K1-K5) in

voltage of 16 to 18 volts passes through its coil. This

such a manner that they can be switched into series

deenergizes relays K2(K1) and K6(K5) and opens the

and parallel combination (d below) to provide proper

dc output circuit to prevent damage to the rectifiers

dc voltages and currents for fast- or slow- charging

in case of overload.

6-, 12-, or 24-volt storage batteries. Circuit breakers

(2) 12-volt charging. W h e n B A T T E R Y V O L T S

CB2 and CB3 are connected into the output circuits

s w i t c h S2 is in the 12 position, relays K3(K2) and

o f rectifiers CR1 and CR2, respectively, to protect

K5(K4) are energized. The energizing circuit is from

the rectifiers from overload when the battery

c e n t e r tap 10 of winding 9-11 of transformer T1,

through BATTERY VOLTS switch S2 in the 12

charger is operated in the fast-charge range. Circuit

breakers CB2 and CB3 are thermal type, automatic

position, through the coils of relays K3(K2) and

e s e t circuit breakers. Each is rated at 40 amperes

K5(K4) in parallel, to the negative terminal of

and will open its rectifier circuit when the dc output

r e c t i f i e r CR2. When relays K3(K2) and K5(K4) are

c u r r e n t of that circuit exceeds this value. After a

operated,

two

full-wave

rectifier

circuits,

using

cooling period, the' circuit breaker will reclose the

r e c t i f i e r s CR1 and CR2 connected in parallel, are

e c t i f i e r circuit automatically. Ammeter M2 is a dc

established. This arrangement produces a dc output

a m m e t e r inserted in one side of the dc output cir-

of approximately 12.6 volts at 75 amperes

maximum. One circuit is from the positive terminal

cuit. It indicates the dc output of the battery

charger (charging rate) in amperes. Resistor R1 is a

o f rectifier CR2, through circuit breaker CB3 and

meter shunt for ammeter M2.

ammeter M2 to positive battery connector P3,

d. Switching Circuits. The switching circuits

through

the

battery

under

charge

negative

consists of BATTERY VOLTS switch S2 and

b a t t e r y connector P2, through contacts 3-4 of relay

2-4