Main Article Content


Nowadays with the invent of new technologies the processors in the electronic devices have improved both in performance and speed. QUALCOMM has come up with its design like the MSM7225 which is a 1 core up to 800 MHz Cortex-A5(ARMv7): 32K+32K L1, 256K L2 and the APQ8055 fro the Series 2 which is a 1 core up to 1.4 GHz Scorpion: 32K+32K L1, 384K L2 and Media Tech is in competition with them, but everything comes at a price in this world and here the price paid is the battery life of the devices which results in less TOS(Time on Screen). Now to maintain that TOS frequent charging is done hence consumption of power or electricity is more resulting in more use of resources which is a concern for third world countries. We need to reduce that use to some extent. In this paper a simple technique of cascading 2 circuits namely the dark sensor using a light dependent resistor and a charging circuit of a charger using IC7805 voltage regulator is being used. The result is dark charger which can be used to charge when there is no electricity hence increasing the TOS and use of less electricity .


TOS BC 547 LDR IC 7805

Article Details

Das, A., Sen, A., & Das, D. (2019). Dark Charger with LDR and BC 547 . [email protected] - Preprint Archive, 1(1).


  1. Hwajeong Seo (1986) Surveillance system with light sensor.
  2. Leslie Lamport (1994) LATEX: Portable Dual Mode Mobile Charger with Hand Crank Generator and Solar Panel , Indonesian Journal of Electrical Engineering and Computer Science Vol. 1, No. 2, February 2016, pp. 282 287 DOI: 10.11591/ijeecs.v1.i2.pp282-287
  3. A Manual Mobile Phone Charger, Zhang Tong, School of Electrical Engineering automation Henan Polytechnic, University Jiaozuo Henan 454000, China
  4. Wireless Charger Networking for Mobile Devices: Fundamentals, Standards, and Applications, Xiao Lu, University Of Alberta