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Old 12th Jul 2019, 8:06 am   #18
'LIVEWIRE?'
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Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 7,306
Default Re: How to set the speed on cassette decks.

That Strobe on the take-up spool is read by an optical sensor-usually a photodiode & phiototransistor assembly. The resulting pulses are fed to a detector circuit. When the pulses stop, the circuit switches-in the case of the Uher to change tape direction, in other cases to stop &/or eject the cassette. Car cassette players often used similar circuits and somewhere I have sample circuits from Blaupunkt training courses back in the 80s
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