National Automatic Time Switch

Metal cased wall mounting 24 hour time switch with removable tappets.

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Original Box

Matsushita Timer with original box Matsushita Timer TB3185 in original box This metal cased National timer is unused and in it's original box.

Model number TB3185, 230V, 15A, 50Hz.

The box has a price label of R29.12

TB31 series, Matsushita Electric Works Ltd, Made in Japan.

Front & Back

National Automatic Time Switch, back view National Automatic Time Switch The front has a round plastic window with the clock behind, and a smaller window for the neon indicator.

Specifications are repeated on a label, clock motor uses 2 watts.

The back is plain with a keyhole fixing point at the top, and two smaller holes at the bottom.

Cover Opened

National Time Switch with cover removed National Time Switch with cover removed The front cover clips in place and is easily removed without tools.

Wiring would enter via the two plastic grommets in the base.


Inside view of the National Automatic Time Switch TB3185 Inside, the clock mechanism filsl most of the space, with wiring terminals at the lower edge.

The automatic switch mechanism is top left, manual control next to it, with the neon indicator top right.

The orange and white tappets for on/off are removable, and if not needed can be stored in the plastic pieces to the lower right and left of the clock dial.

Terminals and Manual Switch

National Timeswitch terminals National Timeswitch manual override Closer view of the manual switch and the lower wiring terminals.

A wiring diagram is provided below the terminals, which have a hinged plastic cover over them.

Tappets and switch mechanism

Switch actuator detail on a National TB3185 automatic time switch TB3185 tappets, orange and white The tappets are colour coded and can be clipped into any position on the clock dial to set the on/off times.

Each has a differently positioned metal peg which passes through the black switch mechanism at the top left of the clock dial.