How does a dive light work?

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Dive lights can be turned on easily with a simple press or twist of the switch. But how exactly are the dive lights able to produce light? Let’s find out more. First, it’s important to know the typical parts of a dive light. These components are working together to produce light:

Casing: It’s the protective housing that protects the inner parts of the light.
O-rings: For sealing joints and connections and for sealing penetrations through the watertight housing.
Contacts: Throughout the body of the torch, there’s a thin strip of copper or brass metal, which creates an electrical connection between the batteries, lamp and switch.
Switch: To trigger the light on or off, when you activate the switch, which either signals the flow of electricity to turn the light on, or breaks the connection to turn it off.
Reflector: At the front of the light, situated around the light bulb. This piece redirects the bulb’s rays into a steady beam.
Lamp: To emit light, typically the LEDs, there are DIP, SMD, COB LEDs packaging.
Lens: Protecting the light source, reflector from damage, to help transmit and distribute the light, usually high grade transparent plastic or toughened glass.
Power source: Often a set of batteries, such as NiMH, Li-ion batteries, are used as power supply and to keep the device on.

When the dive light’s switch is activated, it makes contact between two contact strips, which begin a flow of electricity, powered from the battery. The batteries are connected in such a way that allows electricity to flow from the positive terminal of the battery throughout the lamp and back to the negative terminal of the battery. This exchange of electricity allows the bulb or LED to glow. Once the bulb is activated, the reflector targets that new light into a steady beam directed forward and out through the lens.


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