The colour changing LED in this kit is automatically illuminated and starts to cycle through various patterns when the light sensor has detected that is dark. The kit uses the light activated board with a colour changing LED. The kit includes the light activated switch project kit (part 2112), accompanied by a battery clip, battery cage and rainbow LED. All individually bagged and ready for your students to build.
- When in darkness, this Easy Build Kit generates an array of different coloured illuminations using a Colour Changing LED.
- 1 x 100KΩ Potentiometer.
- 2 x BC337 NPN Transistor.
- 1 x 220Ω Resistor.
- 1 x LDR (Light Dependent Resistor).
- 1 x Colour Changing (Rainbow) LED.
- 1 x PP3 Clip Leads.
- 1 x 4AA Battery Holder.
- 1 x Night Light PCB
- PCB Length: 53mm.
- PCB Width: 25.5mm.
- Build Instructions.
- Teaching Notes.
- Autodesk files for this product.
- 3D CAD Files.
- Click here to find out more about Autodesk
- This kit requires soldering.
Teachers can order a sample of this kit (one per school) here. You will need to select the kit from a list of all the sample kits; the stock code for this kit is 2120.
Note: this service is only offered to schools for evaluation purposes only.
This kit is designed and manufactured in the UK by Kitronik.
Night Light designs by students at Plymstock School.
An example of a Colourful Mood Light.
Colour Changing LED demo and explanation video.
Dark Activated Colour Changing Night Light demo video.
A video about our Night Light Kits taken from our Ask Kitronik Live event 2012.
A guide to understanding how a Potential Divider / Voltage Divider works. What is a Potential Divider / Voltage Divider? This is a simple circuit which takes advantage of the way voltages drop across resistors in series.
Learn how to introduce Colour Changing LEDs to mood light projects.
I am having difficulty in trying to get the assembled circuit to work. I have checked all the usual things- Component positions, dry joints etc. When connected to the battery pack nothing happens-with or without LDR covered and variable resistor adjusted. If connected to a mains power supply (set to 6v output), the LED lights briefly before dying off. If I repeat this process the same thing occurs. Covering the LDR and/or adjusting the variable resistor makes no change to the circuit function. Do you have any suggestions?
Posted byon Tuesday, 28 June 2016
There are two common fault on this circuit:
- A wire link is required in place of R3 and is often missed out.
- The input and output connections look similar and can be connected wrong. I’d check that you have the power supply connected to the connection labelled power.
Further fault finding can be found in the teaching notes which can be downloaded off this product page.
If you are still struggling to get it to work don’t hesitate to get back in touch.
Hi, we'd like to replace the battery pack with a smaller 9V rectangular battery so we can make a more compact housing for the whole unit. It says in your notes that the LED has a built in resistor so only the wire connector is needed in R3. However can you state what resistor we would need to put in R3 if we wanted to use a 9V battery to protect the LED?
Posted byon Monday, 16 May 2016
The problem with using a resistor and a colour changing LED is that it is very difficult to use the correct resistor. As the colour changes so does the current requirement of the LED, as such some colours require more or less current to create that particular colour. If you put a resistor with a high value in you would likely stop the LED changing to certain colours, a low value resistor and when the colour changes from a high value current draw to a low value you could damage the LED as it isn’t protected correctly. As such it may be better looking into using AAA batteries instead and keep the power source at 6V’s as per how the kit has been supplied.
Just a point on your LDR circuit, the output is constant and the LED won't turn on, took out LED and verified it's working ok, removed both transistors, tested with multimeter and it's ok and variable resistor is working perfectly, LDR is also working, something seems to cause the output to not turn off when light hits it.
Posted byon Wednesday, 4 May 2016
There could be a few reasons why the LED won’t turn off, if you view page 4 in the following document https://www.kitronik.co.uk/pdf/2120_dark_activated_colour_changing_night_light_essentials_2_0.pdf it shows the possible causes for this. This should resolve the issue, however if you are still having problems please do not hesitate to contact us at firstname.lastname@example.org
Can I substitute a 10mm rainbow cycling LED for the one provided? It emits a lot more light so could affect the circuit? Tim
Posted byon Tuesday, 12 January 2016
Yes you can substitute the 5mm LED for the 10mm one, electrically it is the same.
Can you suggest a suitable switch to add to the circiut?
Posted byon Wednesday, 2 December 2015
Most of our switches would be fine for this, you might want to try this rocker switch. https://www.kitronik.co.uk/c3407-spst-round-rocker-switch.html
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