# Solar Voltage Monitor. Start Up Project 32

How can we confirm the voltage level from the Solar panel ? A 12 Volt Solar panel generates around 20 V DC Open circuit voltage in bright sunlight. The voltage gradually increases from 6 am and peaks in the mid noon between 11 am and 3 pm. Then the voltage from the Solar panel drops to zero around 6 p.m. So we get sufficient voltage for charging the battery for 4-5 hours only in a day. The 12 V battery requires more than 14 V for proper charging. Its current should be above 500 mA. The current rating of the Solar panel is represented in terms of Watts. As a general rule, for each watt, the current will be 80 mA. So a 10 watt Solar panel gives 800 mA current. This depends on the availability of sufficient voltage from the Solar panel. Many factors like corrosion of contacts, loose contacts in connections, dust on the panel etc will affect the current flow from the panel. So how can we monitor the voltage level from the Solar panel. A volt meter can do but we can make a simple LED Meter for this. Its cost is less than Rs.80. It has three LEDs. The Green LED lights, if the voltage from the Solar panel is above 13 V. Yellow LED lights if the voltage is between 9V and 11 V and Red LED lights, if the voltage is below 9V. Remember, the Solar panel is efficient only when the Green LED lights between 11 am and 3 pm.
Continue reading “Solar Voltage Monitor. Start Up Project 32”

# Car Jump Starter. Start Up Project 31

Imagine a situation. We are going for a night drive and stopped the car in a place for some purpose. Then we see that the car is not starting because the battery is flat. It is a totally confusing situation. We will be trapped if this happens in an isolated place. The only way is to leave the car there or wait till morning to purchase a new battery. Don’t worry. Keep a ‘Jump Starter’ always in the car. It will start the car in 5 minutes. Many Jump starters are available in the market but the cost is too high. We can easily make a Jump Starter using a UPS battery. How the Jump starter starts a car if its battery is flat? Actually, the Jump starter has a 12 volt battery inside. When we connect this new 12V battery across the flat car battery, the new battery shares its current to the flat battery. After 5-10 minutes, the terminal voltage of the flat car battery increases to 12.6 volts. It is sufficient to start the car. Jump starter is the improvisation of the conventional technique of connecting the flat battery of one car across the battery of another car using battery clips and wires .That is why the technique is called as “Jumper starting” or simply “Jump starting”. Now light weight Power bank type Jump starters are available with 10,000 to 15000 mAh Lithium Ion battery. These have provisions like Mobile charger, LED light, Distress signal light etc. But the cost is very high around Rs.6000- 10,000. Let us make one Jump Starter with the same provisions like Mobile charger and LED light. The Jump starter can be charged from the Lighter socket of the Car. Its cost is less than Rs.800.
Continue reading “Car Jump Starter. Start Up Project 31”

# Flame Sensor. Start Up Project 30

Why 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.
Continue reading “Flame Sensor. Start Up Project 30”

# Peltier Fridge. Start Up Project 27

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 “Peltier Fridge. Start Up Project 27”

# Anti- Bag Snatching Alarm. Start Up Project 26

Thwart the attempt of a Bag snatching during journey. Keep this Tiny Alarm in your bag and it will beep loudly when somebody attempts to snatch your bag. It can protect your Laptop bag, Mobile pouch, Luggage etc during the journey. It is essentially a “Vibration Alarm” using ultra sensitive Vibration sensor SW 18020 P. So even a mild shake can activate the alarm. Build it and its cost is just Rs.50.
Continue reading “Anti- Bag Snatching Alarm. Start Up Project 26”

# LED Panel Light Analysis. Start Up Project 24

We see lot of LED Panel Lights flooding cool light in commercial buildings, offices, banks etc. I love LED Panel lights because these are high efficient and economic lights. They also not cause any eye strain. Unlike LED Bulbs, the efficiency of LED panel lights is very high and gives the Lumen, K and Power as per the specifications provided because of the use of LED Driver with constant current output .The use of LED driver increases efficiency because the input AC fluctuations will not reflects in the output. So the LED Driver gives constant voltage and current for the LEDs inside the Panel. The result is uniform light throughout the life period of the Lamp as high as 1 lack hours. The only problem in the LED Panel lights is that the Driver may fail if there is a high voltage surge in AC lines that may occur during unexpected lightning or other reasons. But we can easily replace the Driver because it is externally connected. The cost of the Driver is between Rs.50 and Rs.100. Let us analyse one LED Panel light to see its interior and efficiency.
Continue reading “LED Panel Light Analysis. Start Up Project 24”

# Pocket Mobile Charger. Start Up Project 20

No wonder, technology is that much advanced. You can charge your Mobile phone from a single Pen cell or even from a watch battery. The Mobile battery needs 5V for charging and the Pen cell has only 1.5 volt. How it is possible? There comes the help of DC-DC Booster Module with USB. It converts a voltage as low as 0.9V (900 mV) to 5.1 Volt. Its input voltage can be between 0.9V to 5V so it provides 5.1-5.2 V out put through the USB socket. So you can connect any USB device that requires 5V. Irrespective of the low input voltage, the output remains constant as 5.1V. The Module that works on 1.5V AA cell provides 200 mA current while two AA cells give 600 mA current. Let us build one Pocket Mobile charger. It is too small and costs only Rs.100
Continue reading “Pocket Mobile Charger. Start Up Project 20”