Pioneer tuning fork Service Manual page 7

b) Push-button Switch
A switch IN which a button must be depressed each TIME
the contacts are to be opened or closed. Microswitch and
tact switch, however, are excluded from this category.
Push-button switches can be classified by uses, number of
keys, and mechanisms as shown in Table 2.
Power s w i t c h
Push s w i t c h
Signal selector
Table 2 Push-button Switches.
Lock/release (interlock) type locks the newly depressed key
releasing other keys.
Self-locking (latching) type locks by the first press and
releases by the second irrelevant to the state of the other
keys.
Lock/release
Multiple Key
Self-lock
Nonlock
Single Key
Self-lock
Nonlock
Photo 3 Push Switches
Nonlock (momentary or press-to-talk) type opens or closes
A circuit only I N the period a key is depressed. Releasing
the key deactivates the switch.
Power switches employ press mechanism and signal selec­
tors employ sliding mechanism. A signal selector has gener­
ally two contact points for two to eight circuits.
Lock/release type can contain m a n y switches, deals with
many circuits and does not require to pass unwanted con­
tact points to reach the desired point unlike the rotary
switch. With these features multi-gang push switch of lock/
release type is suitable for selecting functions. Switches of
single and multi-gang self-lock types are used in muters,
filters, tape monitors, etc. and those of nonlock type are
used in tape deck R E C muters, key inputs of digital cir­
cuit, etc. Instead of push switches many tact switches dis­
cussed later are being used in digital key input circuit.
Multi-gang push switch has all functions of lock/release,
self-lock and nonlock types. P h o t o 3 shows typical push
switches.
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