[nigel_uno]

http://www.customelectronics.co.uk/sindex.htm

http://www.electronics-lab.com/proje...008/index.html

http://www.tuttala.it/or4/or?uid=tut...index&oid=2709

http://www2.towerhobbies.com/cgi-bin...p?&I=LXVK79&P=

http://www.active-robots.com/product...o-tester.shtml