Chapter 2. THEORY

TM11-6130-227-40

CHAPTER

THEORY

2-1. Block Diagram Analysis

115-volt ac input is connected through current-

(Fig. 2-1)

limiting reactor L1 to the primary winding of trans-

former

T1.

Transformer

has

two

separate

NOTE

s e c o n d a r y windings. The output of one is connected

All

reference

designations

within

(

)

to rectifier CR1, and the output of the other is

pertain to the components

the

connected to rectifier CR2. The fullwave direct-

PP-1660A/G and PP-1660B/G.

c u r r e n t (dc) outputs of rectifiers CR1 and CR2 are

During fast charging,

the contacts of TIME

switched by relays K2-K6 (K1K5) into series or

S W I T C H M1 are closed and the alternating-current

parallel combinations to provide the proper dc

a c input is applied directly to the primary winding

output voltages and currents for fast or slow-

of transformer T1. During slow charging, the

charging 6-, 12-, or 24-volt storage batteries.

contacts of TIME SWITCH M1 are open and the

Figure

2-1.

Charger,

Battery

PP-1660/G,

Block

Diagram.

2-2. Circuit Analysis

T1. Circuit breaker CB1 is a thermal type,

a u t o m a t i c reset circuit breaker rated at 5 amperes.

a. Ac Input Circuit. One side of the 105 to

C o n n e c t e d in series with reactor L1, it opens the

125-volt ac input is connected, by means of plug

input circuit to protect reactor L1 from overload

connector P1 and the ac input cable, through either

w h e n the input current exceeds this value. After a

TIME SWITCH M1 or reactor L1 to CHARGE

cooling period, circuit breaker CB1 recloses the

S W I T C H S1; the other side of the ac input is con-

i n p u t circuit automatically.

nected to terminal 5 of transformer T1. TIME

(2) Setting TIME SWITCH M1 to any time

S W I T C H M1 is a mechanically operated clock with

i n t e r v a l between 1 and 55 minutes closes its elec-

a normally open electrical contact.

trical contact and winds the clock mechanism,

(1) When TIME SWITCH M1 is in the SLOW

w h i c h holds the contact closed until the expiration

CHARGE position, its electrical contact is open.

of the time interval for which TIME SWITCH M1 is

T h e ac input then is connected through reactor L1

set. When the contact of TIME SWITCH M1 is

a n d circuit breaker CB1 to the rotor of CHARGE

closed, the ac input is connected directly to the rotor

S W I T C H S1 and the ac input circuit is completed

of CHARGE SWITCH S1 and the input circuit is

t h r o u g h the selected contact of CHARGE SWITCH

completed

through

the

selected

contact

S1 and the associated tap of the primary winding of

CHARGE SWITCH S1 and the associated tap of

t r a n s f o r m e r T 1 (b) below). Reactor L1 is a choke

the primary winding of transformer T1 (b) b e l o w ) .

that limits the input current applied to transformer

2-1