Voltage consumption of a IC

[harisudharsan]

Hi All,

I am very very new to electronics & have no educational background on electronics. Just wanted to make life simple eazier with electronics. !!

Just want to install a simple indicator for garage door in my grand parents house to keep check on intruders. (I know this is absolutely a worst method of intruder detection. But somewhat better than nothing)..

So i used a simple LED circuit. I had a lengthy spare wire. So connected LED, a 9 V battery and stuck one lead on to the wall and another to the door. So when the door is closed, the light will be on. When the door is opened, the contact breaks and light goes off.
Now the problem is, since the light keeps glowing for ever, the battery comes only for around 20-25 days. So thinking of introducing some IC (like IC 555) to the circuit so that the circuit gets closed only once for every 5 seconds.

My questions is, Would this idea will really increase the battery life (i.e roughly little less than 5 times as before) or the IC would consume more power than the LED would consume ???

I found numerious better circuits over the internet. But just want to keep this as simple as possible as i need to teach this to a little guy for the maintenance. So need some "really simple" suggestions. So I am trying my best not to overload that little guy.

Regards,
S.Sudharsan

 

[Harald Kapp]

To stick with a very simple circuit:

1) Add a series resistor between battery and LED to reduce current consumption (see sticky post on LEDs in this forum).

2) Use a "normally closed" microswitch instead of the simple wire+door scheme. These switches come in diffferent forms with convenient actuators. Connect the switch in series with the batttery, LEd and resistor. Position the switch such that it is actuated by the closed door (closed door ! opens ! the switch). This the LEd will be on only while the door is open. Since normally a garage door is closed more often than open, this will prolong the battery'y life considerably.

 

[harisudharsan]

Thanks for the quick reply !!

Actually i prefered to do this using IC because, the setup for contact and the wiring is already available (old antina wire, The main lead and the outer sheeth and the contact breaker is a nail)

The main reason for this urgent requirement is, the switch is not readily available in the local electronics shop and I wont be coming back to this place for the next 2 months. Since the last battery is used, i have installed new ones..

But atleast for the sake of my knowledge, would introducing a timer IC would raduce the power consumption ??

 

[Harald Kapp]

If you make the LED blink for only a short time and have long periods of OFF then the timer will save energy.

 

[harisudharsan]

Can you Kindly let me know what s the resistor value and Capacitor value I should use to get an optimal battery usage ?

And what will be the ~ time of glow and off of the LED ?

 

[vinod chandran]

Can you Kindly let me know what s the resistor value and Capacitor value I should use to get an optimal battery usage ?

And what will be the ~ time of glow and off of the LED ?

Hi harisudhan,
Why don't you try to make an infrared alarm circuit ?. It's very simple and effective.