Circuit Wiring

This is an automatic emergency lamp with day light sensing, means it senses darkness/night and turns ON automatically. Similarly it senses day light and turns OFF automatically. A simple emergency lamp which does not require any special equipment; even a multimeter to assemble and use. Any individual who can do a good quality soldering must be able to build this circuit successfully.

This can be easily accommodated in the defunct two 6 watt tube National Emergency Lamp or any PL tube type emergency lamp. The difference will be in the working; it will work non stop for more than 8 hours. Deep discharge is taken care by the LED characteristic and over charge protection is taken care by the fixed voltage regulator.This uses a simple 3Pin fixed regulator which has a built in current limiting circuit.

Simple Emergency Light Circuit Diagram: 

The only required adjustment is the preset which has to be set to ensure the LEDs just light up (it should be left at that position). The 5mm LDR is just mounted on top of the emergency light as shown in the photograph. LDR is used to avoid it lighting up during day time or when the room lights are ON. 2 LEDs are used in series; the dropping resistance is avoided and 2 LEDs light up with current that is required for a single LED,  by which energy is saved to a great extent.

This particular circuit has been kept so simple for people who has limited access to components or in other words this is an emergency light that you can build with minimum components. In addition to circuit diagram, He has shared photographs of the prototype he made in National emergency light and a PCB design.

Nowadays the batteries are gaining more and more power, being the only components that fail to provide energy for portable electronic devices. The evolution is rapid, leading manufacturers electronic equipment to attempt to minimize the consumption of their products so that they can operate for several hours using simple batteries trade. In spite of the efforts of manufacturers, the device will absorb a zero power not yet invented. Thus, both small and if the current device is mathematically certain that at some point, after a few hours, days or ethdomades, the battery-drain .

 Automatic Switch for Batteries  Circuit diagram

The purpose of the circuit will describe below, is to keep alive batteries for the maximum time, minimizing unnecessary consumption. Taking a brief look at the circuit, you notice that the few parts that are can be integrated into any device powered by a battery of 9 V. The main trait is that allows current to flow to the load for a minute, since you pressed the switch S1. After this time automatically cuts off the battery connection. The peak current during switching is 20 mA, price satisfactory for most devices that work with batteries, this nominal voltage.

The heart of the construction is a Darlington type transistor PNP (T1), which is driven in a state of conduction through the pressing switch S1. The small current thaoio, which is due to the high rate of aid, makes able to remain in this condition even for relatively small values ??of the capacity of capacitor C 1 (Around 100 MF). The resistance A3 limits the charge current of the capacitor, thus ensuring long life pressing the switch.

Resistance A1 and A2, in conjunction with the capacitor C 1, determine the period allowed to flow, flow to the load. After this time, the T1 is driven in the state cutoff, a condition ensured by R1. In this design, the placement of a diode to protect from any reverse polarity would be an unnecessary luxury, since the maximum reverse voltage that can accept darlington between thasis and emitter (UBE) is equal to 10 V.

The process of charging batteries / battery dry using a series of Automatic Dry Cell Charger (Battery Charger Automatic Dry) uses a pulse system charging current and peak voltage detector batteries dry in the position of full charge. pulse generator circuit in the "Automatic Dry Cell Charger (Battery Charger Automatic Dry)" was built using NAND gates. 

Meanwhile, as the position of full chargenya voltage detector using IC 741 that is set as a comparator with a reference value of full charge battery voltage. So the series Automatic Dry Cell Charger (Battery Charger Automatic Dry) is a dry battery charger that can be used to charge battery charger (battery) that is safe and dry will automatically cut off when the battery charging process has been fully dry.

Automatic Dry Cell Charger (Battery Charger Automatic Dry) above the reading level of the battery voltage via pin 2 of IC 741 to compare with a reference voltage which is determined based on the comparison of the value of R1 and R2. LED 2 functions as an indicator of the charging process and LED 1 functions as an indicator of the charging process has been completed. BD139 Transistor Q1 is a power charger that requires cooling because these transistors will be hot during the charging process the dry batteries.

 It is true that if any one wants to try to direct mengghubungkan between supply with batteries then the batteries can be sure will be filled. But the current flowing through a charged battery can not be controlled and if the battery is full, the batteries will be damaged or worn out if it remains on the short circuit condition.

Working Principle Battery Charger

By the time we put an empty battery charging terminals, transistor Q1 will be activated immediately because the current flows through R1 and would trigger a transistor Q1 base. In this condition the flow that would fill the batteries mostly comes from the collector of Q1 is connected directly to the positive terminal of supply. Then during the charging process increases the battery voltage will increase the current flowing in Q2 base via 10 Kohm R5, VR1 and diode D2. VR1 is a component that is used as an initial calibration to determine the exact position in the planning process of switching circuit. For VR1 you can use a trimpot or potensio according to your taste. At the beginning of filling, arrange potensio at position D3 LED indicators on the condition of death, and the current flowing into the collector of Q1 is not too big and not too small.

If the battery is fully charged, the LED indicator will light up automatically because of an increase in voltage on the battery charge will cause the increase of current flowing at the base of transistor Q2 and will terminate the charging cycle due to transistor Q1 having a cut-off due to lack of base current. Why on condition Q1 base current will experience a shortage of this is because almost all the current flowing in R1 10 Kohm will switch to a diode D1 which is logically connected directly with ground experience due Q2 saturated.
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Component List
1. Resistors: R1 (10 Kohm), R2 (680 ohms), R3 (100 Kohm), R5 (10 Kohm) and VR1 (Potensio / trimpot = 100 Kohm)
2. Diodes: D1 & D2 (IN4002) and D3 (Led)
3. Transistors: Q1 and Q2 (2N3904)
4. 9 volt power supply

The process of charging batteries / battery dry using a series of Automatic Dry Cell Charger (Battery Charger Automatic Dry) uses a pulse system charging current and peak voltage detector batteries dry in the position of full charge. pulse generator circuit in the "Automatic Dry Cell Charger (Battery Charger Automatic Dry)" was built using NAND gates. 

Meanwhile, as the position of full chargenya voltage detector using IC 741 that is set as a comparator with a reference value of full charge battery voltage. So the series Automatic Dry Cell Charger (Battery Charger Automatic Dry) is a dry battery charger that can be used to charge battery charger (battery) that is safe and dry will automatically cut off when the battery charging process has been fully dry.

Automatic Dry Cell Charger (Battery Charger Automatic Dry) above the reading level of the battery voltage via pin 2 of IC 741 to compare with a reference voltage which is determined based on the comparison of the value of R1 and R2. LED 2 functions as an indicator of the charging process and LED 1 functions as an indicator of the charging process has been completed. BD139 Transistor Q1 is a power charger that requires cooling because these transistors will be hot during the charging process the dry batteries.