Energy Saving Auto-Switching Lighting System

15 December 2021

Some people do not have the habit of switching off the lights off in bathrooms,  toilets,  staircases,  corridors,  hallways, or in areas such as inside cabinets or locker rooms.   Also,  the elderly have poor eyesight;  they are prone to falling down after knocking themselves against the walls or poles especially when they are probing in the dark during early hours.  This article wants to share a home lighting system that these people can use at home,  not only to save energy but also to protect the elderly.

Auto-Switching Lighting System?

These are lighting systems that will switch on automatically when someone is approaching the light fittings.  

The "key" of the lighting system is the sensor that will sense the presence of some moving objects. There are generally 2 types of sensors available in the market for the auto-lighting system.   One of them uses Pyroelectric InfraRed Sensors or Passive InfraRed Sensors (PIR) & the other uses Radar Motion Sensors.  For those who are interested to know more about how motion sensors work,  please read here.

What is available in the Market?

There are plenty of different kinds,  types, and makes of auto-switch light fittings available in today's market.  They are all made from LED running either on battery or mains operated. The latter will need an inverter driver to convert the ac supply to dc supply.   

Generally, they fall into the following category:

This project is more interested in using the auto-switch LED lighting system that has a USB charging port.  

Why?  

One can use such a lighting system for wiring up the whole apartment using a cheap and simple wiring system that can be hidden from view and is less dangerous for the novices.   It can save buying a lot of rechargeable batteries and the inconvenience of charging the batteries at regular intervals;  also,  one can innovate to control the lighting system such as making the lighting system only available during dark hours.  

How?

The following is a schematic diagram showing how the wiring system can be set up using the cheap and thin 2-wire flat cable that can be hidden under the carpet,  behind the joins, and alongside the edge of walls or fixed to the wall without elaborated wiring accessories or otherwise normally required under the National wiring codes.  All one needs to observe is to run the cabling system separately from the normal mains cables.   This would not be a problem if the existing mains cables are of the concealed type which is usually encased in metal conduits for added mechanical protection.

Can Give Examples?

Take for example the auto lighting for the staircase,  there is usually a space underneath the staircase where most would convert it to the storeroom.   This is the best place to install the timer and the 5-volt power supply from which wiring will start to go into the bedroom and toilet etc.  

For the staircase lighting,  some might try fancy ideas such as using strings of LED lights or installing lights at every step of the staircase.  This is really not necessary.   It is just a waste of money.  

Usually,  2 nos of 1.5 Watts 10x LED lights as shown attached as the following will be sufficient to illuminate the staircase depending on the flight of the staircase. 

One could also use other types provided they have a USB socket for 5 volt supply.   

If the light fitting is complete with lithium batteries,  one might have to find one that has good and reliable lithium batteries or circuitries that will allow over-charging.  This is because some poor-quality lithium batteries can be a fire hazard when they are overcharged for a prolonged period using non-approved chargers.  The alternative is to have the built-in rechargeable Lithium batteries removed.  

What are the Required Accessories?

Other than the electric solder and wires & usual tools like screwdriver etc,  one might need the following:-

What if I want lights to be on all the time?

Different manufacturers have different designs for these LED lightings.  Some come with extra switching facilities allowing the lights to be adjusted if one wanted longer light-on interval or permanently on or off.  If one really doesn't want a pitch dark room after the auto-light is off;  such as in the toilets or bathrooms,  one might want to install an additional small LED lamp.  either off the shelves or construct one from parts and connect it to the circuit.