Electronic equipment has for many years been designed to be
driven by constant Direct Current voltage, most commonly
12vDC. Some companies prefer to drive their electronic LED's
by giving them a constant current (amps or milliamps) rather than
constant voltage. It is cheaper to manufacture than a
constant voltage driver and you get max light output from the
led..
Their is a problem with this, particularly when switching on.
Often the electronics delivering the constant voltage do not switch
fast enough, so if the load (led's connected) is very little, then
initially the current output of the driver is too much for the LED
and it pops. In other words, the driver needs some time to
balance the output load to the draw being called by the leds in the
circut. This time to take to balance the load may be too long
for the diodes on the circuit. At the same time this device
will fully drive the led at all times, which in will cause it to
run hotter, emit more light, but shorten lifespan considerably.
With a constant current driver, the circuit should be switched off
frequently in order for the LED to cool down.
Then you have the risk when you switch on again.....
Small LED's run at lower than 12vDC voltages. They are
diodes, a diode is an electronic component that only allows
electrons to flow thru in one direction. Initially that
was their primary function, so they were an integral component in
any circuit filtering AC and delivering DC
electricity. Light emitting diodes were discovered by
accident when it was noticed that diodes glowed when they got hot
in a radio transmitter, back in 1907.
Basically what is happening is that a "toll" of a photon is
emitted when an electron goes thru the gate(diode)
So, I recommend rather that constant voltage be used to
drive LED's and then a simple resistor can be used to lower this
voltage to the LED's spec. This way you can actually drive
the LED at about 90% current which will cause it to loose only
about 5% of light output, but it will run much cooler and for a lot
longer. Constant voltage drivers, e.g. switch mode power
supplies, are much more tolerant of varying input voltages, which
is also important for protecting electronic equipment on an
unstable or varying grid supply which we often have in Africa.