TCA561 Motor Contr. Unit - Datasheet or internal Circuit wanted

[tiefbassuebertr]

For the "TCA 561" I need technical informations. Was it produced only as custom made and only for ReVox or was this type ordinary industry standart?
Thank you very much for your replies.

[tiefbassuebertr]

according
aufzu Halbleiterhersteller-Logos-Ecke
and
NXP Semiconductors
the brand name of the TCA561 is Faselec (Philips Switzerland, on IC is the logo used there from 1966-1984)
and the use is for motor control units

[Steerpike]

There is this technical information on it, if you wanted to make your own!
ftp.studer.ch/Public/Products/Revox/Revox_A700/TCA561_50.05.0152_DataSheet.pdf

[tiefbassuebertr]

Originally Posted by Steerpike

There is this technical information on it, if you wanted to make your own!
ftp.studer.ch/Public/Products/Revox/Revox_A700/TCA561_50.05.0152_DataSheet.pdf

Wow - thank you very much. Such website starting is completly new for me (sorry, I am not computer and online expert).
How it is possible in general, to find download-aeras about "google" from websites,
that starts with "ftp" instead "http://www" ??
Perhaps about this way is also to find various data sheets from other stuff - I want to have in the moment various data sheets for optical stuff in cd player -
1) Sharp LTOH30P/LTOH30PA/LT0H30PA/LT0H30P
new Brand of Hologram Laser (LDGU) LT0H30PA inside by Philips CDM12 and VAM12 mech
2) Sony KSS-Series
Databook about SONY's KSS optical pick up series

[Steerpike]

Originally Posted by tiefbassuebertr

How it is possible in general, to find download-aeras about "google" from websites,
that starts with "ftp" instead "http://www" ??

Sorry, I don't know the answer to that.

It was just luck that I knew the location of the TCA561 information, having paged through a lot of Studer & ReVox files in the past.

[tiefbassuebertr]

before the website is deleted I think, it is better to save the datasheet of the TCA561 here as pdf documents. I have an old IC handbook from data-becker, where a lot of analog ICs listed with internal circuits/block diagrams. Maybe there are one or more good known and good to find IC type of motor control units, which are only a little bit different than the TCA 561. This means, that only a small amount of modifications should be necessary. Because the TCA561 is a "hard to find" part, this could be helpful for several users of REVOX and Studer tapes.

[alouko]

Hi,

TCA561 is used in many Studer/Revox tape recorders as motor controller circuit. Eg. in A700 it is used both for capstan motor control and spooling motor control. It is used to multiply two signals, desired motor speed/force and rectified AC voltage. The result is fed to the transistor which moderates the current through AC motor winding. This way, a nice rotating (and flutter free) magnetic field is produced.

For capstan motor, this is enough.

For spooling motors, however, estra features are used. TCA561 also has a selector for one of the analog inputs. In play mode, left tension arm controls the left motor and vice versa. However, in fast winding, left arm controls the right motor and vice versa. This is accomplished selection pins without extra selectors. Other control pins are used to enable and disable functionality.

TCA561 can be replaced with a circuit where multiplication is made with a matched FET pair. FET is used as an adjustable resistor in opamp feedback loop. Later A700 has this FET circuit instead of TCA561. You can check yourself in the circuit diagram at: ftp://ftp.studer.ch/Public/Products/..._A700_Serv.pdf . Just compare Tape Transport Ctrl circuits of earlier and later models as well as Capstan control circuits.

If this needed to be implemented now, I would think three ways:

1. FET circuit of later A700 models.
2. Using opamps and AD633.
3. Atmel AVR: A/D converters as inputs and output with high speed PCM.

One could also copy Studer A810 spooling motor circuit which uses PCM control directly to the motors. But I think this would be an overkill.