This is Bicycle distance meter circuit or Measure the distance by use bicycle wheel as main tool and normal electronic circuits and so important parts are reed switch detect a magnetic force to CD4017 as Decade counter with 10 decoded outputs IC then connected to Optocoupler 4N26, and display to a frequency counter.
Two-wheel vehicle known as the bicycle is a vehicle that has been used for a long time. Not just items truck. Two foot spin took people to their destination only. But also as an exercise to the body. Strong mental health to boot. And currently has a campaign to turn the bike well. In addition to saving energy, then. Considered to reduce pollution to the environment.
The rotation of each wheel. Possible to calculate the length distance as Figure 1 Distance measuring circuit the principle detect rotation in each round. and Determine to rotate Fully 8 rounds. So will display the once.
In this case the diameter of the wheel is about 24-26 inchs. When rotated Fully to on 8 cycle distance of 0.01 miles, or about 16 metre. Calculate the circumference of a wheel. When rotated, the 8 round distance of 16 metre.
The working of circuit
The reed switch-S1 detect a magnetic force by it is connected circuit when has When the magnetic force approach. And turn on the circuit when When the magnetic field away working with resistors-R1, R2 and capacitors-C1,to generate pulse signal to IC1 Count the number of pulses. When count up to pulse No. 8 will have voltage “high” out of pin 6 through R4 to trigger base of transistor-Q1 to working, there are current flow through LED inside the optocoupler-IC2, then send the pulse signal output of pin 7, 8 to go a frequency counter module of distance meter that successfully installed on the bike.
Figure 1 Measure the distance circuits
The magnet plate is stalled on a bicycle wheel. From the center of bicycle wheel about 12.5 inch. The reed switch-S1 is stalled at fork of bicycle in level matches the magnets plate. When magnet rotates matched switch-S1 is fully one cycle. Then, generate pulse signals up to one pulse.
If wheel full in 8 cycle. and will have pulse in to IC1 = 8 pluse. and there are voltage output to trigger to transistor works, then Display to the distance meter once time.
But when wheel rotates to 9 cycle or pulse no. 9 to IC1 will into reset mode or Restart again until full 8 turns. so It will show at the distance meter is second time. Each time the display out to a distance of 0.01 miles. or about 16 metre.
How to builds
This project has a few components so can assemble on the universal PCB board.
Starting equipment lowest first to the assembly. Start from Diode and then resistors and sort of high continuously.
The device has various polarity must be careful with setting the polarity at PCB and the part match together.
The soldering iron is less than 40watts. And Use of lead solder containing lead and tin in the ratio of 60/40. Including the need also to have a flux inside the lead.
The components list
Resistors size ¼W +5%
R2: 100 ohms
C1: 10uF 16V Electrolytic
Q1: BC549C 45V 100mA NPN Transistor
IC1: CD4017, Decade counter with 10 decoded outputs IC
IC2: Optocoupler number 4N26
S1: Reed switch
Small magnet plate
Universal PCB board
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