Hello all and thank you in advance for this probably dumb question. If I have four 3 volt 1 watt LED's in series on a 12 volt supply is the wattage 4 watts at 12 volts? Ergo I could have twelve of these four chip assemblies on a 60w 12v PSU? Best WIshes, Mike
Power calculation is correct, it's however no good idea to drive LED lamps by constant voltage, actual forward voltage is temperature dependant and undergoes type variations. Dedicated LED supplies are using constant current.
Power calculation is correct, it's however no good idea to drive LED lamps by constant voltage, actual forward voltage is temperature dependant and undergoes type variations. Dedicated LED supplies are using constant current.
But only because they have built in current limiting resistors. (so These resistors dissipate extra power.
Unnecessary waste of power, just drive them with constant current.
I mean the LED companies try to develop high efficiency LEDs .. but then you add resisitors to destroy all their effort.
But only because they have built in current limiting resistors. (so These resistors dissipate extra power.
Unnecessary waste of power, just drive them with constant current.
Sadly these are cheap LEDs with wide tolerances. i.e. not 3V ... this may be safer for you to limit the current but they may not be from all the same batch.
Generally you need 1 to 2 sq'" of Cu heatsink per Watt.