Dark Activated Colour Changing Night Light Kit

A:

Hi Dave, Yes you could change it to a single colour Led, however you would also need to change the wire link in R3 to a suitable rated resistor, this would depend on the LED you are using.

A:

Hi Steve, We don’t stock any enclosure or case for this product, but examples of what others have created can be seen here, https://www.kitronik.co.uk/2120-dark-activated-colour-changing-night-light-kit.html under the media tab.

A:

Hi John, Yes the kit could be powered via a USB lead. The colour changing LED can handle a 5V supply so there wouldn’t be any issues. 5v’s is the maximum the kit could be powered with however.

A:

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.

Best regards

Michael 

A:

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.

A:

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 support@kitronik.co.uk

A:

Yes you can substitute the 5mm LED for the 10mm one, electrically it is the same.

A:

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 

A:

The LED that is used in this kit is the 5mm colour changing LED - https://www.kitronik.co.uk/3527-colour-changing-5mm-diffused-led-750mcd.html

A:

This kit uses a colour changing LED, and as such it doesn’t flash. However you could use the standard light activated kit, 2112 and include a flashing LED instead, we sell a range of flashing LED’s https://www.kitronik.co.uk/3538-red-flashing-5mm-water-clear-led-30deg-3500mcd.html  The 2112 kit measures 53mm in length by 25.5mm in width, although you could mount the PCB elsewhere and have the LDR and LED’s on flying leads in the position you require them.

A:

You can run this kit from a 5V power supply with no changes needed, however you can run this kit on a supply up to 9V but you would need to replace the 0 Ohm resistor to ensure the LED is protected.

A:

Yes 3.6V is approximately the lowest voltage you can use. However the disadvantage of using just enough voltage to begin with is that the LED will go out before the batteries are completely flat so there will be some wasted battery life. You would be better using a higher starting voltage to begin with, this would give you a longer running time and less waste on the batteries.

A:

Yes this can be done, however the power would need to be spilt off with a potential divider at 5V, this would then need to be used to power the night light kit. Any voltage above 5V would cause the trigger point to change and would cause the light activated part to not work correctly.

A: Yes, that would be fine.

A: Hi, the reason is because we use the same PCB for this kit as we use for our light/heat activated switch kits which can drive up to half an Amp. For driving a single LED there isn't any need for it. A lot of people were buying the light activated switch kit and a colour changing LED + battery cage so we made it into a kit. to make it easier to buy. Electronically speaking a single transistor would be fine.

A: Hi, Unfortunately that won't work. The output is roughly 0.9V lower than the input. So if you use an input of 2xAA (3V) that gives 2.1V maximum as an output. The colour changing LED needs at least 2.7V to light up. You could do it with 3xAA, the disadvantage there though is that the LED will go out before the batteries are completely flat so there will be some wasted battery life.

A: Sorry for the delay I wanted to test it for myself! Yes it works fine from USB. It normally runs from 6V but I tested it down to 4V and it worked fine. A USB lead supplies 5V so that?s ok. We sell a cable that goes into a USB port and the other end has two wires, positive and negative. You just solder these into the PCB where you would normally put the batteries. The product code for the cable is 4101 and the product page is here https://www.kitronik.co.uk/products/batteries-holders-chargers-usb-power/power-supplies-and-usb-power/usb-power-lead/

A: Yes you can connect more than one LED, though the LEDs won't say in sync with each other. The number of LEDs that you can connect will be determined by the gain of the transistor I suspect that you should be able to connect 3 or 4 LEDs. If you connect more than the gain allows for you won't damage anything, it will just be a case of the LEDs not being as bright and possibly having the colour sequence restarting from the beginning.

A: There's a page here that explains bulk discounts, https://www.kitronik.co.uk/ordering/bulk-buy-discount-for-kits/ if you put the number you want into the product page and click add to cart the cart will show the discount you would receive.

A: Hi Michelle, they probably were talking about the power rating of the soldering iron. For our kits we would advise something around 18-22W, more powerful soldering irons are available but they heat things up much more quickly which can mean students sometimes burn the board or components and damage the tracks. That said, the rating of the iron itself can't stop the kits from working. I'd recommend you send some photos of the kits that aren't working to support@kitronik.co.uk so I can take a look at them.