Security Lighting at Aoral, Cambodia

The journey to Aoral is 4 hours drive on a vehicle, a mini bus, from Kg Speu. The road was rough and muddy. Its like having a full massage for 4 hours. The driver was skillful, able to turn the mini bus into a 4 wheel drive vehicle. At times, we have to come out and push the vehicle because it got stuck in the mud.

Finally we reached Aoral. A brick building, just completed, is use as a medical outpost for humanitarian work where visiting doctors can provide basic medical health care services to the poor in this region.

There is no grid electricity and clean water in this region. Everyone uses their own generator for electricity. This medical outpost will only turn on the generator at night for 3 hours, 6.30pm to 9.30pm, when volunteer medical teams are there.


The project centred around the installation of a Perimeter Security Lighting system – comprising 25 super bright LED (Light Emitting Diodes) lamps, a control box, a switch box, lead acid batteries (purchased) and a diesel generator – at a medical outpost in Aoral, a district in Kampong Speu. This lighting system will provide security lights around the medical outpost throughout the night after the generator is shut down at 9.30pm.

The system consist of a control box, lamps, battery and a switch box.

The control box includes a charge controller with a switching mode power supply, harmonic filters, main fuse and switches.


The lamps are install around the perimeter of the building and driveway.



Two sealed lead acid batteries operating at 24Vdc, each having a capacity of 120AH. From the graph below, the 3 hours of rapid charging by the switching mode power supply at 28.8Vdc and 18 Amperes followed by 9 hours of discharge from the batteries to the 25 lamps is sufficient to sustain for the whole night operations.

The temperature in the control box never reaches 40 degrees Celcius during the battery charging process but the humidity in the box can reach above 80% humidity during the day time.

The switch box controls 4 lighting zones in the area. Mission House Inside, Mission House Outside, Area behind and side, Driveway & Guard House.



At night, the lamps are turned on. The compound is well lit as seen below.

Batam Medical Mission 2007

On 18 August 2007, I joined my church group on a 2 day Medical Mission to Batam Island, Indonesia. The medical team provided free services and medicines to the villagers.

The lady is having her wound treated by a nurse.

A doctor is examining a child, doing a health check.

Finally, a sumptuous dinner at a restaurant. The trip was meaningful. I can see good works done by the medical team.

Solar 3 - LED Lamp Installation & Maintenance

On April 2007, we went to Hope Village again. This time to install more LED Lamps at the orphanage.

The LEDs Lamps are new design with its electronics capable of working at 24Vdc directly and uses 2 Luxeon Star LEDs operating at about 5 watts. We install altogether 5 lamps to new areas where are there are no lightings previously.

We have to replace one faulty lamp which is damaged when rainwater enters the lamp housing and corroded the electronics.