Simple LED Flashlight Circuit (Torch Circuit)

Ignore powerful flashlights.

White LEDs nowadays are very effective and brilliant.

They use only 3V and a very small amount of current roughly 20 mA to illuminate the night.

This simple LED flashlight circuit is shown in the following diagram.

What is a LED Flashlight Circuit (Torch Circuit):

The LED flashlight circuit also referred to as a torch circuit is a simple electronic circuit that generates light by activating a LED.

Compared to standard incandescent bulbs LED flashlights are more energy efficient and last longer which makes them popular.

Circuit Working:

Parts List:

This easy circuit uses two AAA batteries connected end to end in series to provide a total voltage of 3 volts which lights up the LED.

The LED is carefully connected between the positive and negative terminals of the circuit made by connecting the AAA batteries in series.

A push button switch is added in series with the LED to control the circuit pressing the switch turns the flashlight ON and OFF.

When the push button switch is connected by a user it completes the circuit helps in bright activation of the LED.

This small yet informative project is an excellent start for anyone starting out in the electronics industry.

Formulas:

The following formula is used to express the amazing output of white Light Emitting Diodes (LEDs) in regard to modern lighting technology:

P_LED = V_LED × I_LED

where,

• V_LED​ is the voltage across the LED and
• I_LED​ is the current flowing through it.

One should know that these LEDs are incredibly brilliant and provide powerful light which is having a low input voltage of 3V and a low input current of around 20 mA.

Going on to the circuit design the voltage Vtotal that the series connection of AAA batteries provides is calculated by:

V_total = N_cells × V_cell

where,

• N_cells is the number of cells 2 in this artcile and
• V_cell​ is the low voltage of each cell 1.5V.

In this LED flashlight circuit the LED is connected across the positive and negative terminals of the 3V battery configuration with a series configured push button switch serving as the important connector.

The power P_total​ consumed by the circuit can be calculated by the formula:

P_total = V_total × I_total

where,

• I_total​ is the total current flowing through the circuit.

Since there is generally very little resistance generated by the push button switch itotal is calculated as the LED current ILED

How to Build:

To build a Simple LED Flashlight Circuit (Torch Circuit) follow the below mentioned steps for connections:

• Assemble the above mentioned components shown in the circuit diagram including a push button switch, two AAA batteries, a white LED and connecting wires.
• Choose basic equipment such as a soldering iron and wire strippers.
• By joining the AAA cells in series one can choose a total voltage output of 3V.
• Leaving the other positive and negative terminals unconnected connect the positive terminal of the first cell to the negative terminal of the second cell.
• Connect the LED to the positive and negative terminals of the battery.
• With the longer terminal connected to the positive side one should be sure that the LEDs polarity is positioned correctly.
• The push button switch and the LED should be connected in series.
• Connect one switches terminal to the positive terminal of the battery and the other to the positive lead of the LED.
• Select the soldering iron and use it to fix the connections at each junction.
• One should ensure that the soldering is clean and strong for both its mechanics and for conducting electricity.
• Remember to use insulating material or heat shrink tubing to cover exposed connections to lower the risk of short circuits.
• Place the components within an enclosure to keep them in place.
• The push button switch should be positioned such that it can be reached easily by the user.

Closure:

• Once the connection is completed the simple LED flashlight circuit is ready to use.
• It is a fun project that lets one explore the world of electronics.

Conclusion

For individuals who are just starting out in the world of electronics this small but informative project is a great place to start.

With its luminous output and power consumption controlled by the previously mentioned formulas the built in simple LED flashlight circuit is ready to go and provide an hands on start in the exciting field of electronics.

References:

LED-Flashlight

Flashlight