Asked by: BNolan
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Kitronik Light Activated Switch plus wire cutters
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Kitronik Light Activated Switch plus wire cutters and soldering starter kit
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Description
This light-activated kit is also available as a temperature-activated project kit. The output of this board can be used to control other electronic circuits, turning them on automatically when it goes light or dark.
The board has space for an LED with a current limit resistor (both available separately) which will light when the output turns on.
The Darlington pair transistor configuration allows an output current of up to half an amp to be controlled. Operating voltage 3V to 12V (lower voltages allow for better adjustment of the switching point).
Note:
- This kit requires soldering.
Features:
- This Light Switch Kit detects the brightness of its surroundings using a Phototransistor.
- The kit acts as an automated on/off switch (light dependable) for many devices.
Contents:
- 1 x 1MΩ Potentiometer.
- 2 x BC337 NPN Transistors.
- 1 x Phototransistor.
- 1 x 220Ω Resistor.
- 1 x Light Activated Switch PCB
Possible applications include:
- Garden light that switches on automatically at night.
- Drawer alarm, which sounds when a dark drawer is opened.
- Line following robot (using 2 light-activated boards).
Dimensions:
- PCB Length: 53mm.
- PCB Width: 25.5mm.
Requires:
Free samples:
Teachers can order a sample of this kit (one per school) request a sample kit.
You will need to select the kit from a list of all the sample kits; the stock code for this kit is 2112.
Note: this service is only offered to schools for evaluation purposes only.
Buy British:
This product is designed and manufactured in the UK by Kitronik.
Same Day Dispatch
- Orders placed online before 3:00pm Monday - Friday (excluding public holidays and our Christmas shutdown period) are always dispatched the same day provided the goods are in stock. If the goods are not in stock we will endeavour to contact you as soon as possible to discuss a dispatch date.
UK Deliveries
- If you live on the UK mainland and don't have any large materials or lithium batteries in your order it will cost £3.95 (£4.74 including VAT) if you spend less than £40 (£48 including VAT).
- If you spend between £40 and £200 (£48 - £240.00 including VAT, excluding large materials or lithium batteries) delivery is free to most locations, £12 (£14.40 including VAT, excluding large materials or lithium batteries) to Northern Ireland and £15 (£18.00 including VAT, excluding large materials or lithium batteries) to UK remote locations. For a list of postcodes that will be charged the remote location rate: remote area list.
- If you spend over £200 (£240.00 including VAT, excluding large materials or lithium batteries) delivery is free within the UK.
Rest of the world
- These orders are sent via UPS, and the cost is dependant on the service you choose at checkout. Alternatively you can choose the free collection option and have your own courier collect it from us. International orders can only be shipped to the registered card address. Please note: International orders may be charged import duty dependant on local import laws and duty rates. These charges are usually billed to you directly from UPS.
- Delivery times vary for international orders depending on the service selected and the destination. You can see the delivery time and cost at the shipping stage, or by using the shipping estimator from within the shipping basket.
Collection
- If you would like to collect your order, or use your own courier then there is an option you can select during checkout. We do not charge a packaging or handling fee for this service, and you will receive an email when your order has been processed, you can collect half an hour after receipt of this email.
Further Information
- For information about all of the delivery options we offer see full delivery details.
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Q:
Can you use the circuit board for a moisture sensor circuit? If you replace the LDR for probes.
A:
Hi there,
Thank you for your question, in theory yes though it might take a bit of work and technical know how depending on which sensors you use.
Best Regards
Cullen
Answered by: Cullen Lewis
12-Feb-20
Q:
To use the switch output to control another device where current does not have to be limited, such as a buzzer, should R3 be a jumper wire?
Asked by: Diane Brancazio
A:
Hi Diane,
Thank you for your question, that is correct should just be a wire link. You can use the off cut leg of another component for example.
Best Regards
Cullen
Answered by: Cullen Lewis
08-Mar-19
Q:
Description says: The board has space for an LED with current limit resistor. What voltage LED?
Asked by: Gordon Sanderson
A:
Hi Gordon,
Thank you for your question, I am afraid the answer is it depends on the resistor and power supply you are using. This kit does not come with a power supply but theoretically any 5mm LED could be used provided it did not exceed 12V (as this is the limit of the darlington pair). It just comes down to the power supply used.
Best Regards
Cullen
Answered by: Cullen Lewis
11-Oct-18
Q:
Will a 12 volt battery be too powerful for this switch?
I want to use the switch to operate a fan in my greenhouse but the battery will be connected to a solar panel.
Thanks
Asked by: Anthony Morris
A:
Hi Anthony, The kit can handle a maximum voltage of 12V. So as long as does it doesn't supply more than 12V it will be fine.
Answered by: Michael Lockhart
27-Mar-18
Q:
Would a single LED light trip the switch?
Asked by: John
A:
Hi John, It would depend greatly on the LED you are using and also the trigger point you set the kit to but technically yes you may be able to get an LED to trigger the circuit.
Answered by: Michael Lockhart
02-Jan-18
Q:
have you got a copy of the circuit diagram for this please ?
Asked by: Jim
A:
I have updated the product description on the website to include a link to the teaching material, which includes the circuit diagram.
Answered by: Aaron Sturman
06-Feb-13
Q:
Could you please specify the LED and resistor, to be added to this light switch project, as mentioned in the description, so I can buy the lot in one go? Also, will it be obvious where these should be located on the PCB? Thanks, David.
Asked by: David Johnston
A:
You can use any LED with the board. The resistor that is used will depend on the LED you have chosen and the voltage that the board is operating off. Let's take an example of a standard red LED, where the board operates from two AA batteries: All LEDs have a forward voltage drop, for a standard LED this will be about 1.8V. The light switch circuit uses transistors in a Darlington pair configuration and this has a drop of 0.9V across it. Therefor it stands to reason that if the supply voltage is 3V and there is 1.8V dropped across the LED and 0.9V dropped across the Darlington pair then there must be 0.3V dropped across the resistor. A typical current for an LED is 10mA (or 0.01A). From Ohms law we k
now that R = V/ I so in this case R = 0.3 / 0.01 = 30 ohms or the nearest preferred E6 value of 33 ohms. A red LED with 3 AA batteries would require a 150 or 220 ohm resistor A white LED with 3 AA batteries would require a 100 ohm resistor
now that R = V/ I so in this case R = 0.3 / 0.01 = 30 ohms or the nearest preferred E6 value of 33 ohms. A red LED with 3 AA batteries would require a 150 or 220 ohm resistor A white LED with 3 AA batteries would require a 100 ohm resistor
Answered by: Geoff Hampson
25-Sep-12
Q:
Hi Can I buy these in quantities of 10 already assembled? and if so how much would they be? Regards
Asked by: Les Pettitt
A:
Although we do some kits in a pre-assembled version this isn't one of them. The board can be configured to be activated by light or by dark and this is done by placing the components in different places. This would mean having two different version of the assembled board. So unfortunately the answer is no we don?t do them preassembled.
Answered by: Geoff Hampson
18-Jul-12
Q:
Hi Kitronik, Can i use this kit to make a mood lamp style project and use a colour changing LED as the light output?? Thanks
Asked by: Simon
A:
Yes it is possible to put a colour changing LED on the board, in fact because a lot of people do this we have a kit that includes the colour changing LED and a battery cage. If you have a look on the related items on the left it is the dark activated colour changing LED kit you need.
Answered by: Geoff Hampson
29-May-12
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