This guide explains how to adapt a Zeon 'CE1780' Talking Clock for disability standard switch use. This technique follows for almost all talking clocks, the main difference being the location of the 'speak the time' switch contacts.
If you're an absolute beginner, we strongly recommend that you follow "The Basic Soldering Guide" - by Alan Winstanley.
SAFETY: Adapting equipment voids the manufacturer's guarantee, and the attempt may cause irreparable damage. Always use adapted equipment under supervision, and disconnect any batteries when not in use. These adaptations are at your own risk.
You can obtain talking clocks from many sources such as Argos for less than a tenner. For clocks with higher quality speech, and English accents, try the RNIB. All other components are commonly available from Electronics stores such as Maplin Electronics.
Open up the casing. Make a small pilot hole where there is enough space to house your 3.5mm socket. Drill a 1/4" hole (circled in yellow), being careful to stop as soon as you're through.
Unscrew the Printed Circuit Board (PCB), and gently pull it down.
With this Clock, there are two 'Talk' switches both covered with a white foam. Peel this, and the metal contact off, then discard.
If you touch a piece of wire between the inner and outer circle, this will make a contact, and the clock should speak. Remove the batteries.
Scribe two small pilot holes in the board, then very carefully drill 2x 2mm holes as pictured.
As not all sockets are connected alike, you will need to find which 2 of the 3 contacts you need to solder to.
Attach a test lamp or multi-meter to any 2 contacts. Plug in your switch, then press it. If the lamp comes on when pressed you have the right connections, otherwise try a different combination. There's only 3 possibilities.
Solder two lengths of wire to the socket. Expose the ends, tinning them if you wish.
Solder your socket to the Printed Circuit Board (PCB) switch connections, aiming to have nothing jutting out from the board.
Blow on the board to cool it down as soon as the solder flows. Too much heat could damage the workings of the device.
Put the PCB back in place, and screw the 3.5mm socket into the casing. Test the device with a switch. If all seems OK, put it all back together being careful, when tightening up the socket, not to twist the wires too much.
Test the unit with a switch several times, then leave it alone for a few minutes. If it activates by it's self repeatedly, there's probably a short circuit. Pull it apart again, and examine the accuracy of your soldering carefully, especially on the socket.
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Jumbo Display Talking Clock (c) Zeon Tech