Flame Sensor. Start Up Project 30


8AWhy going for a costly Fire Alarm system? Some of the Fire alarm systems cost more than Rs.2000. You can make an efficient Fire warning system for just Rs.20. It uses only a few components and is a very efficient Flame sensor. The Thermister based commercial Flame sensors have a drawback because, the alarm sounds only when the Thermister turns hot by the nearby flame. That means, the alarm sounds only after the room is full of fire. But this tiny circuit overrides that drawback. It uses a Photodiode as Fire sensor. It sounds the alarm even if the flame is far away . Interestingly, the spark of the first fire burst can activates the alarm. It can be installed in Home, Commercial shops etc. It will not activate in the ambient light of the room like that of Fluorescent light. It sounds the alarm only when it detects a light similar to a flame, sunlight or incandescent bulb. It is battery operated and in the standby state the current consumption is as low as 5 mA. So Simple, Efficient, and Low cost. Build it.
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Servicing a Maintenance Free Battery. Start Up Project 29


6BI found that my UPS is not giving sufficient back up as expected for 20 minutes. I thought that I have to spend Rs. 800 to replace the battery. But I was not in a hurry. Want to find out the reason. After 5 minutes, the PC shutdowns. Why so? The UPS battery is not giving sufficient power (Ampere Hour) to run the load. The UPS battery is a 12 volt 7 Ah (Ampere hour) Maintenance free Sealed LeadAcid battery (SLA). That means, it is “Maintenance free” and can be used for long time without any attention. But what happens is, the cells dry out due to heat generation. This happens after 6 months to 1 year of use . It is a Lead Acid battery that requires Electrolyte in the cells. So water is necessary inside. It has 6 individual cells giving 2V each. After removing the battery from the UPS, I found that it is very easy to rejuvenate the battery through “Hydration”. The battery will become top, if the dry cells are filled with battery water. Hydrated the battery and charged. Well, now it is giving more than 15 minutes back up. Saved Rs. 800 and reduced an e-waste. You can also rejuvenate the 6V Emergency lamp battery like this. So do it yourself. It is only a 10 minutes job.

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