Light Up in the Dark Circuit (LDR)

This is an LDR (Light Dependent Resistor) Circuit made for a lamp to provide light during the nighttime. This circuit utilizes an LDR, a transistor, a potentiometer, an LED, and a battery. Using the advantage of more resistance on the circuit while having a lack of light, we can provide a reasonable amount of light during nighttime.

LED (Light Emitting Diode)

LDR (Light Dependent Resistor)/Photoresistor

Transistor

Potentiometer

Battery

Wires

Solder

Soldering Iron

Breadboard

Materials needed for this step:

Photoresistor (LDR)

Once you've gathered your electrical components, it's time to start assembling your LDR (or photoresistor) circuit on your breadboard. This could be considered essential to your final project because it will greatly aid you when trying to create the circuit on a matrix (perf) board, and will help you save both time, energy, and materials. This is crucial to prevent errors during the creation process and short circuits, which can harm components. Errors can have a detrimental effect on the project as a whole and need unneeded halts, which is why I consider this step to be crucial.

1.) Grab your breadboard and connect a battery to it, which could be connected to the computer (otherwise, get two wires, one in a positive slot in the breadboard, and one in a negative slot, and connect to a power source (generator, power source)

2.) Assemble the circuit as shown in the completed GIF and picture

3.) Turn the battery on (or power source) using crocodile clamps and make sure it is functional

4.) Check to see if it is functional (if when a significant amount of light is taken away, the LED lights up, indicating more resistance)

5.) When functional, take note of the circuit and remove components, you have completed your prototype, and you are ready for the Matrix Board, your final product for this level of the lamp.

Materials needed for this step:

LED (Light Emitting Diode)

LDR (Light Dependent Resistor)/Photoresistor

Transistor

Potentiometer

Wires

Solder

Soldering Iron

HOW TO SOLDER LIKE A PRO

1. Materials:

Perf board

Electronic components (resistors, capacitors, ICs, etc.)

Soldering iron (preferably with adjustable temperature)

Solder (60/40 tin-lead or lead-free)

Wire cutter/stripper

Thin, insulated wire (or pre-tinned hookup wire)

Soldering stand with sponge or brass wool

Desoldering pump or wick (for mistakes)

Tweezers (optional for small components)

"Noah, how do I apply the solder to the perf board?"

Place the tip of the soldering iron against the pad (the copper ring around the hole on the perf board) and the component lead at the same time. Allow it to heat for 1–2 seconds.

Once the pad and lead are heated, touch the solder to the joint (not the soldering iron). The solder should flow smoothly and form a shiny, cone-shaped joint around the lead.

Once the solder has flowed, remove the iron and let the joint cool naturally (should take just a few seconds).

"What happens if I make a mistake?"

If you make a mistake, use a desoldering pump or wick to remove the solder. Then, correct the placement or connection and re-solder.

Now it's time for the real deal. Once you have your components and materials, take your matrix board and assemble the circuit using your previous work and knowledge. Be careful not to touch the matrix board too much with your bare hands, though, because the acids from your hands could be detrimental to the board.

1.) Lay all of your components out on the perf/matrix board

2.) Solder the components to the board (as shown in picture)

3.) Connect to a power source/power generator with crocodile clamps

4.) Check to see if it is functional (if when a significant amount of light is taken away, the LED lights up, indicating more resistance)

You've made your LDR circuit! It is now up to you where you want to take this.You could turn this into a functioning home lamp, lights for your room or your home in the night, or anything your heart desires, don't hold back!

I give you my thanks for reading, and happy construction!

“Imagination rules the world.”

– Napoleon Bonaparte