Introduction: Night Light Socket

About: Electronics Professor Retired.
This project presents the simple and economical way to do an automatic socket with photo cell, based on an adapter for socket double contact, we can find at any hardware store, to control the ignition of an incandescent bulb, when there is no ambient light. This socket is very useful for an outdoor patio or lighting to illuminate a garage, especially when one goes on vacation.
This socket is placed between the main socket and bulb, on and off automatically depending on the brightness of the environment. It has input to a standard bulb and maximum capacity of 100 Watts.
Requires that the person who wants to build this device, have basic electricity, electronics and safety knowledge, as well as, you possess a digital multitester. No batteries required.
Electronic devices are available in a store of electronics (such as STEREN, for example), adaptor for socket at any hardware store, as well as welding, and solder paste.

Step 1: Parts.

The following materials are required to build this socket with photo cell:
1 TRIAC 4A 600V (2N6075A or similar)
1 Capacitor 0.1 uF 250V
1 resistor 1W 56KΩ (or an arrangement of resistors that provide the approximate value)
1 photocell resistive 5 mm
1 double socket adapter contact (without chain)
solder paste
1 soldering pencil
1 digital multitester
Nose pliers
Cuticle nippers
Phillips screwdriver
Small screwdriver

Step 2: Electronic Circuit.

The electronic circuitry that controls the ignition and off floodlight is based on an electronic device of solid state called a TRIAC (triode in alternating current) which operates as a switch that lets or no power to floodlight.
Then, when the photo cell does not receive sunlight or artificial light presents a very high resistance, and is as if it were disconnected from the circuit, and has no influence, and electric current flows into the DIAC (diode in alternating current), through resistance and capacitor, that triggers the TRIAC, allowing the floodlight to be light. When the photocell if you receive direct sunlight, dramatically lower its resistance and leads the current mentioned towards the neutral of the electrical installation and the TRIAC is it blocks, turning off the floodlight. The function is automatic, as long as the normal switch of the floodlight on or activated.

Step 3: Assembling the Electronic Circuit.

First, indicate that this electronic circuit is not assembled in printed circuit, but components weld among themselves, as it is shown in the sequence of images.
Devices are placed and its terminals are rolled, and then welded the pencil soldering iron. The recommended sequence is:

TRIAC to DIAC, Capacitor to DIAC + TRIAC, Resistance to TRIAC + DIAC, and finally, Photocell to TRIAC + DIAC.

IMPORTANT: be careful not to short circuit between the electronic components.

Step 4: Disassembly of the Adaptor Socket Double Contact and Preparation.

Take adapter socket that we buy at the hardware store to disarm it. First remove the screw using the Phillips screwdriver.
Second, remove carefully the upper contact of the adapter with a small flat screwdriver. We separate the 2 parts of the adapter as shown in the figures.
Also, a hole of 5 mm is made for that photo cell comes out of an adapter.

Step 5: Welding Parts.

The electronic circuit will be connected in series with the bulb, while the adapter connects in parallel with the same energy. Therefore, must cut one of the internal contacts (neutral) adapter, as shown in the figure, to weld the 2 sections with the electronic circuit as is illustrates., must also apply duct tape to the other contact (line) of copper as the figures indicate.
Finally, join the 2 parts of the adapter carefully, screw is placed and put the top contact, with a flat screwdriver.

Step 6: Final Considerations.

Once armed the socket, should be a continuity test with digital multimeter. Without placing the incandescent bulb, or connect to the mains AC adapter, connect the multimeter in continuity function (whistle), and must have continuity in the line of energy, but should not have it in neutral line (remember that we open and connect these electronic circuit) if any continuity in the neutral will have to open the socket then you most likely have a short circuit.
Finally, we put the bulb on the socket and connect it to the socket stream where you want to locate the light, and check its correct operation.

IMPORTANT NOTE:This socket does not work with FLUORECENT LAMPS, only with incandescent bulbs.

I wish you good luck in the manufacture of this system of energy saving.

Best regards.
Weekend Projects Contest

Participated in the
Weekend Projects Contest