These are a few simple LED circuits. They can be used as warning lights - as fake motorcycle alarms - as a doorbell substitutes for the deaf or hearing impaired.
Connecting LEDs In Series
Connecting LEDs in series is very efficient. You can light several LEDs - with the same amount of energy it takes to light just one. The reason is simple. With one LED - the series resistor wastes most of the energy - in the form of heat. But when you connect several LEDs in series - the energy that would have been wasted in the resistor - is turned into light instead.
The more LEDs you connect in series - the smaller the voltage drop across the resistor. And the smaller the voltage drop across the resistor - the smaller the amount of power it has to dissipate - i.e. waste.
Fake Alarm - Circuit No.1
The first circuit is described in complete detail. The remaining two circuits are only slightly different from the first - and their descriptions deal only with those differences. Therefore - to understand how the later circuits work - you should begin with Fake Alarm No.1
Fake Alarm - Circuit No.2
The last circuit will flash up to two groups of 5 LEDs in tandem. This circuit will flash the two groups alternately. The alternate flashing creates the illusion of movement - and makes the display more eye-catching.
Warning Signal - Circuit No.3
This circuit is like the previous one - except that it will flash up to 15 groups of 5 LEDs per output. The LEDs will also flash at a faster rate - and they will glow at their full brilliance. Unlike the more discrete "alarm fitted" indicators - this circuit is designed to get your attention.