Simple LED Flashlight Circuit (Torch Circuit)

Forget bulky flashlights.

Modern white LEDs are incredibly bright and efficient.

They can light up the night with just 3V and a tiny amount of current around 20 mA.

The following diagram shows a basic LED flashlight circuit.

What is a LED Flashlight Circuit (Torch Circuit):

A LED flashlight circuit also known as a torch circuit, is a simple electronic circuit that powers a light emitting diode to produce a source of light.

LED flashlights are popular due to their energy efficiency and longevity compared to traditional incandescent bulbs.

Circuit Description:

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 engaged by a user, it consummates the circuit facilitating the radiant activation of the LED.

For those embarking on their journey into the field of electronics this modest yet illuminating project stands as an ideal initiation point.

Formulas:

Let us incorporate some basic formulas to enhance the technical aspects of the explanation:

In the world of contemporary lighting technology the luminous output P_LED​ of white Light Emitting Diodes LEDs can be expressed by the formula:

P_LED = V_LED × I_LED

where,

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

Remarkably, these LEDs exhibit exceptional brilliance and can achieve potent illumination even with a modest 3V input voltage and a meager input current of approximately 20 mA.

Now, turning our attention to the circuit construction the total voltage V_total supplied by the series connected AAA cells is given by:

V_total = N_cells × V_cell

where,

• N_cells is the number of cells 2 in this case and
• V_cell​ is the nominal 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 crucial intermediary.

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

P_total = V_total × I_total

where,

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

In this scenario, I_total​ can be approximated as the LED current I_LED​ since the push button switch typically introduces negligible resistance.

How to Build:

• Collect the requisite components, including two AAA cells, a white LED, a push button switch, and connecting wires.
• Employ basic tools such as a soldering iron and wire strippers.
• Position the AAA cells in series ensuring a cumulative voltage output of 3V.
• Connect the positive terminal of the first cell to the negative terminal of the second cell leaving the remaining positive and negative terminals unconnected.
• Attach the LED across the positive and negative terminals of the battery configuration.
• Exercise caution to align the LEDs polarity correctly, with the longer lead connected to the positive side.
• Integrate the push button switch in series with the LED.
• Connect one terminal of the switch to the positive terminal of the battery, and the other to the positive lead of the LED.
• Employ the soldering iron to secure the connections at each junction.
• Ensure tidy and robust soldering to guarantee electrical continuity and mechanical stability.
• Apply insulating material or heat shrink tubing to cover exposed connections averting the risk of short circuits.
• Arrange the components within an enclosure securing them in place.
• Position the push button switch in an easily accessible location for user engagement.

Closure:

• Once you connect everything your simple LED flashlight is ready to use.
• It is a fun project that lets you explore the world of electronics.

Conclusion

For those embarking on their journey into the field of electronics this modest yet illuminating project stands as an ideal initiation point.

The constructed simple LED flashlight circuit torch circuit, with its luminous output and power consumption governed by the aforementioned formulas is poised for operation offering a hands on introduction to the fascinating world of electronics.

References

LED-Flashlight

Flashlight