Simple LED Bike Light Schematic

We know flashing LED lights from the high street shop. But, they were often gave me trouble with flat batteries and lights that fell off. In this case, we make a better one idea using another front wheel, one which has a dynamo already built in the hub. This supplied a nice sine wave of 30 Vpp (at no load). With this knowledge I designed a simple power supply. The transistors that are used are type BD911. These are a bit of an overkill, but there were plenty of these at my school, so that is why I used them. Something a little smaller will also work. The power supply is connected to an astable multi-vibrator. This alternately drives the front light and the rear light. This is the figure of the circuit.

Simple LED Flasher Circuit Using LM3909

This is a very -very easy and simple LED flasher circuit with only needs three components that are: a flasher IC, a LED and an electrolytic capacitor. Here’s the figure of the circuit;

 

Component list:
LED1_________Red LED
C1___________100uf/16V
IC1__________LM3909

Simple Flashing Neon Circuit

This is design circuit that is used for one, two or three neon indicator bulbs can be made to flash in sequence at rates determined by the R and C values. This is the figure of the circuit.


In the single stage circuit, using one lamp, the capacitor charges through the resistor until the ionization potential of the neon is reached (about 70 volts) and then discharges quickly through the lamp until the voltage falls below what is needed to sustain the lamp which is approximately 45 volts. The cycle then repeats at a rate of about 3 Hz for values shown. Smaller R or C values increase frequency, larger values decrease frequency. All capacitors should be the non-polarized variety with a 100 volt or more rating. For more than 3 stages, the lamps may need to be matched for similar turn-on voltages.