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:
| Type | Specification | Quantity |
|---|---|---|
| LED | White 20mA 5mm | 1 |
| Push Button | 1 | |
| Cells | AAA 1.5 Cells | 2 |
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 dazzling output of white Light Emitting Diodes (LEDs) in regard to modern lighting technology:
PLED = VLED × ILED
where,
- VLED is the voltage across the LED and
- ILED is the current flowing through it.
Though having a low input voltage of 3V and a low input current of about 20 mA these kind of LEDs are remarkably bright and deliver strong illumination.
Moving on to the circuit design the total voltage Vtotal provided by the AAA cells are connected in series is calculated by:
Vtotal = Ncells × Vcell
where,
- Ncells is the number of cells 2 in this case and
- Vcell 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 important connector.
The power Ptotal consumed by the circuit can be calculated by the formula:
Ptotal = Vtotal × Itotal
where,
- Itotal 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 steps for connections:
- Gather the necessary parts mentioned in the above circuit diagram such as a white LED, two AAA cells, a push button switch and connecting cables.
- Select simple tools like wire strippers and a soldering iron.
- Find out a cumulative voltage output of 3V by connecting the AAA cells in series.
- Connect the first cells positive terminal to the second cells negative terminal leaving the other positive and negative terminals disconnected.
- Connect the LED to the battery configurations positive and negative terminals.
- Take care to ensure that the LEDs polarity is correctly positioned with the longer lead attached to the positive side.
- Connect the LED and the push button switch in series.
- Join one of the switches terminals to the batteries positive terminal and the other to the LEDs positive lead.
- To secure the connections at each junction choose the soldering iron.
- For mechanical stability and electrical continuity one should make sure the soldering is strong and clean.
- To reduce the chance of short circuits remember to cover exposed connections with heat shrink tubing or insulating material.
- Keep the parts in place by placing them inside an enclosure.
- The user should place the push button switch in an easy to reach position.
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 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.
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