stepper motors

The Replacement Stepper Motor Driver article referred to a digital clock input. What is this ? Would an oscillator based on the astable 555 circuit do ? I am trying to build a clock mechanism with a stepper motor driven by the replacement stepper motor driver.

Posted by Gerry Kingston (fgkingston@aol.com) on 15/11/2004, at 17:51 GMT

Clock

A 555 astable circuit can be used to provide the square wave clock input required.

Posted by John Hewes on 15/11/2004, at 22:19 GMT

The 555 as a Clock Signal

The 555 astable will certainly do!

A 'digital clock' is simply a signal that changes from 0V to 5V (or whatever the power supply voltage is) and back again regularly. These clock signals are used in electronics to keep different parts of a circuit synchronised, and the clock speed is measured in cycles per second, or Hertz (Hz). For example, the clock signal inside a modern PC might run at 1GHz - that is 1 billion 0V-to-5V-and-back-to-0V cycles per second.

For an interesting example relating to the digital ICs described on the old Electronics in Meccano website, please see the article about my Moving Message Display System at:

http://temp.eleinmec.com/mmds.htm

A quick link to the circuit diagram is:

http://temp.eleinmec.com/MMDSF22.gif

You will see (at the top left of the diagram) that the circuit uses a 555 astable as the 'system clock' and this is routed to quite a few of the counter ICs to keep them running in sync. The speed of this clock is 1.5kHz (1500 cycles per second).

Hope this helps!

Posted by Tim Surtell on 16/11/2004, at 04:26 GMT

New URL for MMDS

The MMDS information is now on my personal website at:

http://www.surtell.com/projects_mmds.asp

Also includes some new photos!

Posted by Tim Surtell on 12/02/2007, at 18:24 GMT