Jayathilaka, K.M.D.C.2016-06-232016-06-232015Jayathilaka, K.M.D.C. 2015. Lesson 11: Transistor switch connected to relay and control the external load, In: Practical Manual for GCE A/L Biosystem Technology Teachers. Ministry of Education and University of Kelaniya, Sri Lanka. 69-72 pp.978-955-4563-50-6http://repository.kln.ac.lk/handle/123456789/13651enLearning Object