All of us living in independent houses have this one common worry – “leaving the house locked for too long”. During our time away from home we would usually arrange for neighbors to frequently inspect and turn on the lights in the house for a certain duration to give the impression of some one staying. I used to do this until 5 years back when I tried out a digital timer for controlling the portico light. Seeing the trouble free performance and comfort it gave, I added more timers to automatically turn on/off lights in the hall, puja room, etc.
Programmable digital timers made in Taiwan or Germany are easily available in the market at affordable prices ranging from Rs.600-Rs.1000/-. These timers can also be ordered online.
The digital timers that I have been using in my house is Frontier make, Taiwan. It is very cheap, compact, reliable and can be easily mounted on existing switch boards or elsewhere as per your convenience. You can also choose other country makes as per your choice and budget.
Choosing the Model
The timer comes with certain input/output voltage (110-130 V ac, 220-250 V ac, 24 V DC and 12 V Dc) and current capacity ( 16 A/32 A) options according to the model number. So it is required to choose the right model number as per your application. In my case since my application is in India and the light that I control is operating on mains power supply from the electricity distribution company, I chose the option of 220-250 V ac. I use a timer with a current capacity of 16A for this purpose. Please check the relevant voltage option as per your country supply system if your application is connecting to the electricity grid supply. You may take the help of an authorized electrician for installation of timer.
- The timer has a quartz controlled clock with lithium button cell that maintains accurate timing even during power outage.
- It has facility for setting the time and day of the week.
- The following modes are available – Manual, Auto and Off. For automatic operation it is necessary to set the mode in Auto.
- It is possible to have multiple on/off on a single day as per user requirement.
- It is possible to select on which days of the week this control is required.
- The timer provides LED status indication for ON/OFF. LED glows in the ON condition. For more details please refer to the datasheet that comes with the purchased item.
- In my case I have simply chosen to switch on the lights at 6.00 PM and switch off at 10 PM on all days of the week. These settings can be easily changed whenever required.
- Sometimes it may be required to switch on/off outside these preset timings. The regular switch already available on the switch board for the chosen light can be used for the purpose. The timer output is therefore connected in parallel to the switch.
The front view of the timer is shown below:
The various control buttons such as manual , clock, timer, day, hour, minute and LED status indication are clearly visible. Using the datasheet, follow the procedures to set current day, time and timer On/Off time.
The rear view is shown. The rear view shows the specifications and the connection pins with the legend.
The circuit diagram for the model selected is shown below:
The timer is connected across the existing switch and the lamp circuit as shown. The switch can be used to turn on/off the lamp in case of requirement outside the timer setting hours.
The timer pins( 1-5) are knife type pins. So use appropriate lugs with insulated sleeve crimped wires for connection to the timer.
The line and neutral connections can be found inside the switch board. The switch board has to be opened for fixing the digital timer and making the wiring changes as shown in the circuit diagram. Ensure that power mains are switched off during the installation.
The picture showing the digital timer after installation is shown below:
The above timer is in use for the past five years. I have installed three such timers controlling lights in different areas of my house and use it on a regular basis.
Note: The wiring and connections have to be done only by qualified personnel or authorized electrician.