Advertisement
11. MOTOR DRIVE SECTION
The motor drive (Capstan, Cylinder & Loading motor) IC becomes all new. Both of the cylinder motor drive circuit and the loading
motor drive circuit are included in IC2501.
11-1.CAPSTAN DRIVE CIRCUIT
There are two major different points between Z-Mechanism and R4-Mechanism described as follows:
1. High speed driving mode
2.Drive signal has been changed:
1.R4 Mechanism employs Full time Full-wave drive method
The Z-Mechanism uses both full-wave and half-wave drive depends upon VCR Mode.
In Z-Mechanism, the half-wave motor drive method is used in high-speed driving mode(such as FF, REW, CUE and REV mode),
in stead of full-wave motor drive method.
(The half-wave and full wave is switched by TL (Torque Limit) signal which is supplied to IC0201(CAPSTAN MOTOR DRIVE IC)
-pin12.)
IC6001
Main u-COM
However, the R4-Mechanism employs full-wave driving method in any time.
What are the difference between half-wave drive and full-wave drive?
In generally, each methods has following features:
Features
Half-
*Driving
wave
Torque:
driving
SMALLER
method
*Number of
rotation:
HIGHER
Full-
*Driving
wave
Torque:
driving
BIGGER
method
*Number of
rotation:
LOWER
NOTE:
It is quit difficult to say which method is better, but, in generally, since the full-wave driving method uses two phases in a path,
relation between current, voltage and generated torque are efficient compared with half-wave driving method.(Half-wave driving
method uses only one phase in a path.)
WHAT ARE THE DIFFERENT BETWEEN Z-MECHANISM & R4 MECHANISM IN TERMS OF HIGH SPEED MODE?
The immediate conclusion is that the method to be increasing the tape winding speed is different.
In terms of the Z-Mechanism, the number of Capstan rotation is increased to increase the tape winding speed.
(Therefore, Z-Mechanism uses half-wave driving method in high speed driving mode.)
In case of the R4 Mechanism, Reel rotation speed is increased with changing the gear ratio compared with R4-Mechanism.
(Suppose, while capstan rotates in a time, Reel table rotates 10 times, in terms of Z-Mechanism.
However, in R4-Mechanism, Reel table rotates 20 times, while one capstan rotation.
Therefore, R4-Mecanism is able to use the full-wave driving method in high speed driving mode.)
High-speed Driving mode
(FF, REW, CUE, REV)
Other than above mode
Z-Mechanism
High (5V): Half-wave Drive
Low (0.4V): Full-wave Drive + TL
1
(TL: Torque Limit)
2N
FF/REW
(Half-wave)
N
FF/REW
(Full-wave)
FF/REV
Slow
Rotation
FF/REW
(rpm)
Rorque T (gcm)
Z-Mechanism
Half-wave drive
Full-wave drive
Linear drive signal
IC0201
12
1/2T REV
Slow
T
51
R4-Mechanism
Full time Full-wave drive
PWM drive signal
CAPSTAN
MOTOR DRIVE
CAPSTAN
Advertisement
