Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!lll-winken!uunet!mcsun!hp4nl!maestro!tamtam!cees
From: cees@tamtam.htsa.aha.nl (Cees Keyer)
Newsgroups: sci.electronics
Subject: Re: speed control on a cassette deck
Keywords: cassette, speed
Message-ID: <245@tamtam.htsa.aha.nl>
Date: 14 Sep 89 08:23:51 GMT
References: <4053@ct.sei.cmu.edu> <7683@microsoft.UUCP> <3997@wpi.wpi.edu>
Reply-To: cees@tamtam.UUCP (Cees Keyer)
Organization: AHA  TMF (Technical Institute) Amsterdam, The Netherlands
Lines: 26

In article <3997@wpi.wpi.edu> reynhout@wpi.wpi.edu (Andrew Reynhout) writes:
>
>   I can tell you from experience that altering tape speed on a cassette deck to any useful degree is *NOT* as simple as lining a pot through the supply for
>the motor.  Sure, you can do that, BUT... if you do, the possibility exists
>that it either won't work at all, or will work with adverse effects on the 
>regularity of tape speed.  (faster then slower, producing interesting but
>generally undesirable effects on the recorded material.)
>   I was at a loss for years as to how to circumvent the adverse effects of 
>slowing a tape deck.  I mean, I knew that Sony did it, but couldn't figure out
>how to do it myself.

Almost all the cassette deck motors are equipt with a tiny printed circuit board
in the motor casing. On this board there is a transistor (medium power transistor)
which keeps the speed constant. If you take this board out you can control the speed 
by altering the resitance of the pot.
The pot can mostly be reached trough a hole in the bottom of the motor casing.
On some decks the motor speed control is outside the casing of the motor it self.


No asid rain on my brain :-)

-- 
DISCLAIMER: All the opinions expressed are my own.
Cees Keyer, Algemene Hogeschool Amsterdam.      
department of electrical engineering.          
cees@tamtam.htsa.aha.nl cees@maestro.htsa.aha.nl UUCP: mcvax!hp4nl!htsa!cees