Growing demand of energy is almost everywhere, leading people to think of using it more efficiently. In this regard, we are proposing the auto-light unit, which has many pros over the existing similar products in the market.

Working:
Above mentioned PIR sensor based automatic light, senses any movement within 7 meter radius range. Take an example of a corridor, when no person is present, respective light will be in off mode. Now, if any person passes by and comes in that prescribed sensor range, his movement will activate the system and thus light will switch on till that person presence. Switching OFF action can be delayed using the incorporated timer in the same unit. Hence a fair reduction in electricity consumption is achieved as when no person is present in corridor during night time lights would be switch off.

Moreover, LDR have been incorporated in the unit to keep the light OFF in presence of ambient light above prescribed level of intensity. Thus day light saving is achieved. In addition a central unit can be employed to controls all electrical utilities in a single room. Lights at staircase, balconies, bathrooms etc, security cameras and theft alarm, exhaust in public bathrooms are the few applications of this system.

In terms of power requirement, the circuitry requires only 0.2 Watt in idle mode (switch off condition) and 1 Watt in running mode, thus use of such automation leads to energy management and energy conservation.

Comparison with the existing systems:
• User friendly design and can be easily mounted on existing electrical sockets. (other automatic products need to be installed with skilled electricians)
• A flexible sensor arm provides freedom for selecting the sensing area, direction and range of the automatic lights. (no such provision is there in existing products)
• LDR is employed for day time saving. (not present in most of the existing products)
• With manufacturing cost of “5 $ (US)”, much cheaper, compared to existing PIR based automatic products. (NOTE: Quality of the components used in the unit are not compromised for cost and the product is tested for time)

Manufacturing details:
Circuitry for automatic light is housed in a machined PVC end cap with ventilated plastic closure. The input signal for automated switching of light is received to the circuit from PIR sensor, which is mounted in metal flange with plastic cover at PCB side. The PIR sensor and main body is connected through a flexible rigid pipe which provides a flexible movement to the sensor for setting it into desired direction. Regular male and female electrical sockets are used for mounting at general household points. In addition the LDR mounted on end cap body helps in day-light saving.

In electronics; a led driver converts the 230 VAC signal to 05 VDC signal, necessary for PIR and other mounted components on PCB. For desired AC output for switching the light, the PCB generated DC signal, actuates the relay, which in turn switches ON the light.