Decorative light sources are readily available on the market as gift items. Here the project presented demonstrates how to operate it using TV remote control (or any other remote control of AC or music system etc.). Remotely operated it needs to be modified, within its Internal Circuits and there is also need to build a Simple Circuit using IR Sensor to detect the IR Remote Signal.
The available decorative light sources look like this
Fig. 2: Image of decorative light sources
First disconnect the fiber optic cables. You will see 3 different colored LEDs inside – RED, GREEN, BLUE.
Fig. 3: Image of LEDs inside light sources
Now remove the top cover to see the internal circuitry. As shown in the image, inside there is a Simple Circuit with 3 LEDs at the top and a COB at the bottom (Not Visible in the Image provided). The circuit has only four external connections – 2 for power supply (through battery cells as shown) and 2 for push button. Simply disconnect the push button connections as shown. These two connections will be connected to the IR sensor circuit.
Figure 4: Image of the Internal Circuit of Decorative Light Sources
IR Sensor Circuit
The circuit is very simple, built using TSOP1738 IR Sensor, two NPN Transistors and a C/O relay.
See the circuit diagram guide for the circuit at the top.
Circuit Description
The sensor output is connected to the base input of the NPN transistor Q1. Transistors Q1 and Q2 are connected in the switch configuration. The relay coil is connected between Vcc and the collector of Q2 as shown. The common (C) and normally open (NO) terminals are connected to the Light Fountain switch terminals. So now, instead of the push button, the relay switch is connected.
Here is the image of the circuit built on breadboard
Fig. 5: Light source prototype on breadboard
Circuit Operation
Typically, the sensor output is high. Therefore, transistor Q1 is ON. Therefore, the collector output is low. Since its output is an input to Q2, Q2 is OFF. Therefore, the relay is also off (de-energized). When the IR signal reaches the sensor, its output goes low. So Q1 is OFF. This makes Q2 ON. Then the relay is energized and switches on. This makes momentary contact between the C and NO terminals. This contact activates the COB and turns on the light source.
Each time any of the buttons are pressed on any TV remote control, the relay contact activates the Light Fountain and it turns ON. The COB performs different functions on each trigger. As
· Turns LEDs on and off in alternating firing
· It switches alternating LEDs, first just RED, then just GREEN, then just BLUE, then RED-GREEN and in the same way
· Also flashes all 3 LEDs with different effects to generate an excellent overall lighting effect
Here is the image of the complete circuit setup with Light Fountain
Fig. 6: Image of the complete light source circuit configuration
Circuit diagrams
| circuit_20 |  |
Project Components
- CITSOP1738
- LED
- Resistor
