PROJECT: Light Activated Switch - 1

Eco Tech Hobbyist Association of North Bengal

(ETHAN)

Siliguri

PROJECT REPORT

1. PROJECT NO: 2009/02

2. NAME OF PROJECT: Light Activated Switch - 1

3. PROJECT OBJECTIVE: To save electricity by automatically switching on or off various lights such as Street Lamp, Glow Signboard, outdoor lamp etc..

4. SALIENT FEATURES: Simple Auto Switching of different type of wattage, voltage & Lamps.

5. PROJECT IDEA BY: Rajib Biswas.

6. PROJECT HEAD: Ajay Das

7. ASSISTED BY: Rajib Biswas & Raju Sarkar,

8. STARTED ON: 15^th March 2009.

9. TIMELINE OF VARIOUS STAGES (ALONG WITH PHOTOGRAPHS):

14^th March 2009: Initially, we intended to use a phototransistor. But it was not readily available. So we found an alternative simple circuit using a LDR. The circuit is given below.

15^th March 2009: we have assembled the electronic components on the general purpose PCB (Vero board) successfully switched a LED.

18^th March 2009: Attached a SPDT relay to the circuit. The relay can be switched by the circuit. Thus, by using the relay, we can switch any isolated electrical device operating on AC 220 V.

25^th March 2009: Able to run a CFL running on 220V AC.

30^th March 2009: Installed the completed device with on the outdoor lamp (CFL) of our ETHAN office. Running satisfactorily.

10. WHETHER COMPLETED: Yes.

11. COMPLETED ON: 15^th April 2009.

12. COST OF MATERIALS (DETAIL):

No.	Item	Amount / Size / Desc	Quantity	Price (Rs)
1	PCB	Small 4x4 CM	1 pc	10.00
2	Relay	6volt	1 Pc	15.00
3	Transistor 2N2222		1Pc	7.00
4	LDR		1Pc	8.00
5	Preset OR Variable Resistance	100K	1Pc	15.00
6	Resistance	50K	1Pc	1.00
7	Diode	IN4001 OR IN4007	1Pc	1.00
8	Weather Proof Transparent Cabinet	8cmx5cmx3 cm	1Pc	10.00
			Total	67.00

13. COST OF LABOUR / MACHINING: Nil.

14. WHETHER OBJECTIVE ACHIEVED: Yes

15. DIFFICULTIES FACED: Identifying the different pins of Transistor. Finding a suitable photo transistor. Finding a suitable cabinet.

16. SUGGESTIONS FOR IMPROVEMENT: To make the device water proof. To provide L E D as indicator. Include the power supply inside the cabinet. To find a better cabinet.

17. REMARKS: Safety Measures: - Always be careful when you soldering any Electronic parts on PCB. We must be alert about parts temperature tolerating level that is encoded on the components body. Other wise it will be harmful for those components.

18. CONCLUSION: Good performance achieved. The device is automatically switching a CFL running on 220 Volts AC.

19. REPORT COMPILED BY: Subho Shankar Hore.

20. Tools required: - Soldering Heater, Soldering wire, Soldering Paste, Wire, Wire Cutter, Desoldering Wire, Desoldering Pump.