Don’t throw away oldLaptop battery; it can be reused for other purposes. I hacked one Laptop battery and salvaged six high efficient Samsung Lithium Ion batteries each rated 3.6V, 4300 mAh. It is worth Rs. 1000. Few days before, I found that, my Laptop is not getting enough back up and shutdown immediately when the charger is removed. So I replaced the battery at the cost of Rs.1200. Due to curiosity, I just opened the case of the old battery pack and found that, the batteries inside can be reused. After testing, I found that only one battery out of the six is damaged. All the other five are in good condition. That damaged battery created the problem in the battery pack and prevented the remaining five batteries from their work. So actually this is happening in our Laptop. If one battery fails, we have to replace the battery pack. If the good batteries are salvaged from the old pack, we can reuse them for many different applications like LED lighting, Mobile charging, making power supply etc. So I spend Rs.1200 for the new battery pack but I salvaged 5 good batteries worth Rs. 1000 from the old battery pack. So my actual expense is only Rs.200. So do not discard the old Laptop battery. Tear it, salvage the individual batteries and reuse. You can save money and can reduce the e-waste. Continue reading →
You know, we can light a 1 watt LED without a battery! Peltierwill give “Free Electricity” for that. When we heat the Peltier with flame, hot water or a hot object, it starts to generate current. Its voltage can be around 1.5V when the heat is above 60 degree. But this 1.5V is not sufficient to light even an ordinary LED that requires 1.8V minimum. 1 watt White LED requires 3.6V. Then how? We can add a Joule Thief circuit for that. A Joule Thief circuit is a self oscillating circuit that increases the input voltage as low as 700 mV to 4-5V. So if the Peltier is connected to a Joule Thief and heated, Joule thief will amplify the voltage to light the 1 watt LED. Let us check this. Continue reading →
Peltier is the Fantastic device used to make cooling devices. When a current of more than 500 mA passes through the Peltier, its one side cools while the other side turns hot. This is due to the transfer of heat from one side of the Peltier semiconductor to the other. As the current increases above 1 Amps , the cooling effect increases and the temperature of the cold side of Peltier drops below 0 degree. But if we reverse the function of Peltier, it generates electricity. For example, if we heat one side of Peltier above 60 degree using a hot object, hot water or flame, Peltier generates around 1.6V DC and around 350mA current. Let us make one circuit of “Free energy “generation using a Peltier Module. Since the 1.5V from the Peltier is not sufficient for lighting an LED, we have to add a voltage booster to increase the Peltier voltage sufficient to light the LED. If 5 Peltier are serially connected, we can even charge our Mobile phone using a Candle flame.
I 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 volt7 Ah (Ampere hour) Maintenance free Sealed Lead – Acidbattery (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.
One Damaged Mosquito Swatterwas in my home with full of dust. So, decided to salvage its parts to reuse for other purposes. Just to avoid e –waste and to do some kind of Recycling. Well, it has a good 2.4VRechargeable Battery and a circuit board. The problem is in its circuit board that generates highvolt AC to burn the Mosquito. But the charger is still working. So decided to use the charger part to make a High power Rechargeable LED Flash light. The Mosquito Swatter generates a high voltage between 400- 1000 volts from the 2.4 V battery. For this, there is an oscillator circuit and an Inverter transformer. The Inverter transformer converts the 2.4 V DC from the battery to around 200V AC. The oscillator circuit makes the AC waveform. The 200 V AC thus produced is then boosted by a Voltage Multiplier comprising some high volt capacitors and diodes. This boosted AC appears in a High volt Capacitor which then passes it to the Nets of the Swatter. The middle net of the Swatter is Positive while the outside nets are Negative. When we press the switch, the High volt capacitor discharges high volt AC to the nets. When the Mosquito passes through the net, it explodes due to high voltage. Even though the AC voltage is very high around 1KV, Current is negligible. Let us see how that Swatter turned into a Rechargeable Flash light. Continue reading →
Wow! We can make a cup of cold water in 5 minutes without a Fridge. You need only a Peltier Element, a 12 volt high current battery and a Computer cooling fan. Peltier element is a semiconductor plate like device with Cold and Hot sides. When we provide 12 -18V, 1 amps power to it, one side of the Peltier suddenly cools and the other side turns hot. The cool side temperature goes down below 0 degree and the hot side becomes around 100 degree. So to transfer that much heat, the Peltier should be placed over a large Heat sink. A Computer cooling fan with heat sink is the best choice. Fan will remove the heat from the Peltier and heat sink. At the same time, the cold side turns too cool in minutes. Without a heat sink, the Peltier will be damaged. If we reverse the Polarity (+ and –) of the power supply to Peltier, the sides reverses. That means, cool side becomes hot side and vice versa. Let us make one Peltier Fridge to get some cold water. Later we can change it as a heater to drink hot water. Peltier costs around Rs.200. Continue reading →
One of my LED Bulbsshowed some unusual behaviour during the Peak hours. Unusual dimming, flickering, lighting faintly after switch off etc. It is a 15 watts LED bulb purchased for Rs.300. Checked its specifications. It is 980 Lm and 6500 K . That showed that there is something related to Watts, Lm and the K. The manufactures say that, instead of Watts, look the Lm before purchasing the LED bulb because “Watts” is an obsolete term for the LED bulb. Then what are the Lm and K? Lm is the short form of “Lumen” which is the measure of total amount of light from a source. As a general rule, a 100 watts ordinary bulb gives 1500lumen light. K is the short form of “Kelvin” which is the measure of “Colour Temperature “of light. For example, the day light has 5000K and a White LED Bulb gives around 6000 K . As the Colour temperature value increases, the light turns more and more white then turns to blue. Lower values of K shows Yellow to Red light. So as per the specification, the LED bulb should give 980 Lumens and 6500 K light. Ideal its specifications. Then what is happening in it. Analysed thoroughly. Continue reading →