Akai VS-2EGN

7-1-3 LOGIC CONTROL
Vee
Ves,
2
(voutace oF PIn@)|/
VP/R P.B/REC
Vcc ~ VMH PB
VMH ~ VTH PB
VTH~ VTL P.B REC
VTL~ VML REC
VML~O REC
(a)
Fig. 7-110 Operation of Logic Control
ae P/RSW
PIN @ REC PB MUTE, P.B REC MUTE
=P.B > |SPB = REC = MUTE = REC
Vee == = = a Se = = 4 ~~ -- + -- --- = -- = --4 ----
Ve VM
—vtH
ve
VM
TIME
Te To Tio
IC1 (BA5102) used in this circuit employs an Electro-
nic Switch (E. SW) so that the same circuits may be
used for the Record and Playback circuitry.
The switching terminal is controlled by a voltage appli-
ed to pin @. Switching to REC mode is made on LOW
voltage input, switching to PB mode is made on HIGH
voltage input, and switching to PB MUTE mode is made
on MIDDLE voltage input.
Fig. 7-111 shows the timing chart during transfers bet-
ween REC and PB modes. As seen from (a) pin @4) and
78
J A ~~ Als s
il iy tf
Fig. 7-111 Operation of Muting Control
(c) LINE OUT, when REC is switched to PB, the con-
dition at time T3 is HIGH voltage, so that the. PB audio
signal is connected to the output. Then, as PB is switch-
ed to MUTE, MUTE is applied at time position T4.
Though switching from normal PB to Muting is instantly
accomplished, when returning from MUTE (STILL or
QUICK FINDER mode) to normal PB, the audio signal
is connected to the output after the tape run becomes
stable, with the time constant arranged slightly longer
than this to ensure reliable operation.
‘Service Manual VS-2EGN