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Step 9How I Put Together The LDR And Alarm Unit
This box is considerably bigger because I had to fit two 9 volt batteries and a pretty big alarm. I removed the LED from the LDR side of the circuit because it is not needed but I kept the LED from the Alarm side because it must be there. I mounted it on the box so that it would light up when the alarm activated. It also acts as an improvised low battery indicator. If the LED light but the alarm doesnt sound, I know that the battery must be weak.
The alarm that I used also had the function to make a pulsing sound instead of a single tone which was cool and it also allows me to have some control over the loudness of the alarm. The alarm I chose is rated at a very loud 120Db at 12 volts, but Im only using a 9 volt battery and only 6 of those volts make it to the alarm, so Im hearing about 60Db which is pretty loud on a full battery.
The switch on the top left turns on the LDR half of the circuit and the one on the far right turns on/ re-sets the alarm.
You can also see what I meant by using a tube as a light shield for the LDR, it works very well and allows the system to be very sensitive.
http://www.youtube.com/watch?v=kxvch0Lu3os&feature=channel_page
I cant give you a step by step explanation of how to solder everything because there are just so many possibilities plus I didnt take any photos or video of my soldering all of the components. Anyway take a look at the pictures for a closer look.
The alarm that I used also had the function to make a pulsing sound instead of a single tone which was cool and it also allows me to have some control over the loudness of the alarm. The alarm I chose is rated at a very loud 120Db at 12 volts, but Im only using a 9 volt battery and only 6 of those volts make it to the alarm, so Im hearing about 60Db which is pretty loud on a full battery.
The switch on the top left turns on the LDR half of the circuit and the one on the far right turns on/ re-sets the alarm.
You can also see what I meant by using a tube as a light shield for the LDR, it works very well and allows the system to be very sensitive.
http://www.youtube.com/watch?v=kxvch0Lu3os&feature=channel_page
I cant give you a step by step explanation of how to solder everything because there are just so many possibilities plus I didnt take any photos or video of my soldering all of the components. Anyway take a look at the pictures for a closer look.
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Jan 25, 2010. 10:49 AMhandyman29
says:
Where are the 4 fixed resistors on you IC board. I only see the pot. and one other resistor beside the 6 year old transistor?
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1
Sep 12, 2009. 10:09 PMkk khrab
says:
Could You plz send me a message as soon as possible i am only interested in charging the batteries. i got heaps of batteries but no knowledge of charging it with solar panel or cell i use i blocking diode which is not as good.
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1
Sep 16, 2009. 12:28 AMrevhead (author)
says:
Sorry it took me so long to reply, I have been getting lazy with checking my emails. I can help, but I need to know what battery you want to charge? Is it a small rechargeable battery or a larger battery like 12 volts?? I need to know how many "volts" the battery is rated at and how many "mA/h" it is rated at. The mA/h rating it usually found printed on the side of the battery. Oh, I’m sure you know this but I will mention it any way, you can only recharge batteries which say that they are declarable, you can’t recharge all batteries. Let me know the details of the battery and I will help as best I can. :) CHEERS!
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