Pioneer tuning fork Service Manual page 12

2 . 3 Parts N u m b e r i n g S y s t e m
OUR numbering system of switches is as follows:
Part Number Descriptions
SAOOOO) Power s w i t c h
S A - 0 0 0
SBOOOO) Rotary s w i t c h (to be terminated
SB-000
w i t h a binder)
SCOOOO) Rotary s w i t c h (to be terminated
S C - 0 0 0
w i t h a binder small type)
Rotary s w i t c h (others)
S D - 0 0 0 SDOOOO)
SEOOOO) Rotary s w i t c h (slide type)
S E - 0 0 0
M i c r o s w i t c h
S F - 0 0 0 SFOOOO)
Push s w i t c h or t a c t s w i t c h
SG-000 SGOOOO)
SHOOOO) Slide s w i t c h
S H - 0 0 0
Lever s w i t c h
SK-000 SKOOOO)
SL-000 SLOOOO) Snap s w i t c h
SMOOOO) Sea-saw s w i t c h
S M - 0 0 0
Plate spring s w i t c h
S N - 0 0 0 SNOOOO)
S X - 0 0 0 SXOOOO) Others
Table 3 Numbering System of Pioneer Switches
10
Relay
Relay is a kind of switch activated by electro-magnetic
force.
1 . B A S I C STRUCTURE
A relay is made of an electromagnet and contact pieces.
While the coil is open, the movable piece C touches the
fixed contact piece B (break contact). In Fig. 10, when a
current is applied to the coil, C is attracted by the sole­
noid and touches the fixed piece A (make contact.)
Spring
Coil Yoke
Fig. 1 0 Structure of Relay
2 . KINDS OF RELAYS
Relays are classified into four; power relay, protective re­
lay, small current relay and reed relay.
2 . 1
P O W E R RELAY
Power relay that functions at a predetermined value of
power is used in surge killer circuits of high power ampli­
fiers to reduce inrush current which flows when power is
turned on or in A C power circuits remote-controlled by
an infrared ray. T o withstand a high voltage and large cur­
rent, this relay uses Silver C a d m i u m Oxide (AgCdO) at
contact points. The dimensions of contact pieces are larg­
er than those of the other to radiate heat.
A B