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Old 5th Jul 2019, 7:41 am   #1
TonyDuell
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Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,191
Default Philips tape recorder power supply/remote adapter

I am not sure if this can be dignified by the term 'equipment' as it is just 3 connectors, a switch, and a bit of wiring. But I have found it useful when working on Philips tape recorders.

Many older Philips cassette recorders and the EL3586 portable reel-to-reel machine have a 5 pin 240 degree DIN socket for power input and remote control. This means that (a) you can't use both simultaneously (although I have heard that Philips once made an adapter for this, I have never seen one) and (b) you can't use 'normal' power supplies and remote control devices.

The adapter simply provides a coaxial power socket and a 2.5mm jack socket wired to the a DIN plug. If nothing is plugged in, the recorder runs as normal from the internal battery. Plugging a PSU in disconnects the battery and runs the recorder from the PSU. Plugging a remote control in allows that to control the recorder (whether it is run on batteries or a PSU).

The switch is a centre-off SPDT one, its function is based on a similar (slide) switch on a Tandy cassette recorder which I found very useful. With the switch towards the power socket the recorder runs all the time (no matter what the remote control is doing). Switch in the middle -- recorder off. And switch towards the remote control socket allows the remote control to control the recorder.

The first photo gives the circuit diagram, the second shows the internal wiring and the third shows me testing it with an EL3302.
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