Introduction: Led Bicycle Safety Lights(pedal Powered) Under $10
bicycle riding is fun and also good for our fitness plus it doesn't consume any fuel and thus good for our environment too. But riding a bike in night could be dangerous ,so here is a tutorial of how to build safety bicycle led lights which are powered by a generator or dynamo.
Step 1: Step 1 : Getting Right Material and Tools
1) 4x(1 watt white led)
2)12x(3mm red led)
3)key board button
6)nut and screws
7)dc motor from old tape recorder
9)iron sheet (4x10cm )
11)2x(7805 5v regulator)
tools used :
1)hot glue gun
6)drill machine with 3mm bit
Step 2: Step2: Front Led Lights
-take the iron sheet , mark a line 1 cm from the bottom
-bend the iron sheet to 90degree with the help of pliers
-confirm the cathodes of 1 watt led ( negative mark (-) on the terminal) and solder the 4 1 watt led on the iron sheet as shown in the image
-the iron sheet will act as ground or negative
-now solder the 7805 regulator to the sheet as shown,connect the key board switch to pin 3 as shown
front led light is complete.
Step 3: Step3 :rear Led Lights
-take the zip ties and cut the starting and end with the help of wire cutter
-mark 6 marks each 2.5cm apart from each other as shown
-now the tricky part, make holes for the 3 mm led pins with the help of a board pin
-connect all led in parallel
-solder 100 ohm resistor
Step 4: Step4: Adding Dynamo/generator
here we will use a tape-recorder motor(dc motor from old tape recorder)
-take the dc motor and fix a rubber wheel on it
-select the best place for the motor so that it should make contact with the wheel rim
-now take aluminium sheet and and mark for the cuts according to the rear frame of bicycle
-cut the aluminium sheet with metal sheet cutter
-cut a strip out of aluminum sheet as wide as the lenght of motor's body. Bend the strip on the motor and make a c-shape (this will help in holding the motor in 1 place)
-take the motor and aluminum sheet and freely place it on the frame for measuring the best positon for the motor .make sure that the motor must not collapse with the wheel spokes .
-drill holes for the screws.
-Fix the assembly of dc motor with the help if hot glu and clear tape.
Step 5: Step5: Putting Rear Led on Bicycle
-first,take clear tape and tape over the area on bicycle where the led strip is to be placed(this is done so to make surface non conducting which can cause short circuit)
-place the led strip that we made on the bicycle rear frame and with the help of clear tape , just tape it from the each led gaps as shown
-bend each led about 45degree to 50degree
Step 6: Step 6: Placing the Front Led
-connect/solder the flexible wire for input from the generator
-take the front led ,that we made in between the handle bar
-place it flat and bend the metal plate at the angle that makes the led becomes parallel to ground
-tape it on the handle bar or you can also use zip-ties or hot glue to make it fix there
-find the best place where you can to fix the switch for front leds , and glue it with hot gule gun. I chose to fix the switch beneath the break lever for using it as dipper .
Step 7: Step7: Connections
-first rotate the wheel and check the output of motor for determining the + and - terminals
accordingly solder the diode (this done to stop the voltage getting back to the motor)
-take flexible wire and connect the front led with motor's output-now take 7805 regulator and connect it to the both rear led strips. From the + output terminal of motor, add 1ohm resistor and connect it to the input of 7805
(the 1 ohm resistor is added to make a voltage divider for front leds because more current will flow where the resistance is low thus, here more current will flow to front leds )
-spin the wheel and check whether the leds glow or not
hove fun and ride safely :)
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