Building a Dark Detector Kit
Product Code : EL-AS-11125
Last updated: 6 October 2026
Quick answer: A grades 9 to 12 kit in which students build a working night-light from LEDs, a transistor, a light-dependent resistor and resistors, with a free downloadable activity guide. Materials support 1 to 3 students.
Students build a functioning dark detector, a night-light that switches on as the light fails, from discrete components: LEDs, an NPN transistor, a light-dependent resistor and resistors. Because the circuit does something recognisable when it works, the transistor stops being an abstraction and becomes the part that makes the lamp come on.
The published learning outcomes are specific. Students learn how electronic light sensors operate; how NPN transistors function, with their three elements acting as a solid-state switch; and how light-dependent resistors control current flow while LEDs demonstrate the characteristics of semiconductors, with both devices relying on the photoelectric effect. That last point is the link to atomic structure: the photoelectric effect is where the quantum behaviour of light becomes measurable on a bench.
The kit is specified for grades 9 to 12 with materials supporting 1 to 3 students, so order one kit per small group rather than per class. The activity guide is a free download rather than printed matter in the box.
The component values, the number of each part supplied, whether a breadboard or soldering is required, and whether a battery is included are not published. Those decide whether the kit is usable as delivered, so ask before ordering.
Technical specifications
Specification | As published |
Product type | Electronics construction kit, light-sensing circuit |
Grade level | Grades 9 to 12 |
Students supported | 1 to 3 per kit |
Components, as listed | LEDs, a transistor, a light-dependent resistor and resistors |
Activity guide | Free downloadable guide |
Concepts covered | Electronic light sensors, NPN transistors as solid-state switches, LDR current control, LED semiconductor characteristics, photoelectric effect |
Supplied from | Ambala, Haryana, India |
Only what this listing publishes is recorded above. Component values and quantities, whether a breadboard or soldering iron is required, whether a battery is included, and whether the assembled circuit is reusable are not stated. Confirm these before ordering, and note one kit supports only 1 to 3 students.
Range and ordering
This item belongs to the Atomic Structure family within Biotechnology Equipment and Labware, part of the Biotechnology range. Packaged teaching kits are listed under Biotechnology Kits. Bulk, tender and OEM quantities are handled through lab tenders and OEM orders; use the contact page to request a quotation or any specification noted above.