LEDs are polarised with positive and negative. Before any wiring is performed, the polarity of LED should be identified. If the reverse voltage applied to LEDs is too high, it may damage them permanently.
There are two types of basic LED lighting circuits:
(1) Constant Voltage (CV) – LEDs are wired in “Parallel”, voltage across each LED is constant while current varies depending on the rating of LEDs. e.g. 12V @ 0~5A
Connect the power supply’s positive to all LEDs’ positive and negative to negative as shown below. Connect as many LEDs like this as you want but make sure the total wattage does not exceed the power supply’s rated wattage.
Typical LED products that requires a constant voltage circuit is LED strip lighting or ribbons.
(2) Constant Current (CC) – LEDs are wired in “Series”, voltage across LEDs varies depending on the number of LEDs, while the current through the circuit remain constant. e.g. 24~48V @ 700mA
Note: Always switch on mains power after the circuit is complete. Never connect constant current LEDs to a live circuit, this will damage the LED immediately and permanently.
Typical constant current LEDs: LED down lights, LED High Bay lights, LED Chip Modules etc…