Creative Commons LicenseThis image is released under a CC BY-NC-SA 4.0 Licence

Buy this image as a print 


License this image for commercial use at Science and Society Picture Library


Science Museum Group
© The Board of Trustees of the Science Museum

Sequential Timer Programmer developed and built by Dr Jack Tait, Clyro, Herefordshire, England, 2012

This is the last timer in a group of 4 sequential timers that are the ‘brains’ of some of Jack Tait’s analogue drawing machines. Although not as user friendly as the first one, it was the most sophisticated of all with a complex system of programming the sequences via variable pins placed in a rotating holder and a variable system for distributing the output.

Timers are the machines’ programmers and send variable time pulses to the different machine motors. When Tait's machines are outfitted with timers, the set up functions as an analogue computer.

For example, in X-Y plotters like the NSEW machines, they send the pen in two directions. Each axis motor needs instructions to start, stop, go forward or reverse. Instructions that come from the sequential timer, are simple e.g. ‘X Motor forward 3 seconds then stop.’ Simple time variations create the most complex and rich drawings.


Object Number:
Donated by Dr Jack Tait