How to Build an Electric Fan
In this project, we are going to build a battery-operated, handheld fan, such as one shown above, which is common to see inside of a discount store or supermarket.
This fan, like any other, blows so that a person can keep him or herself cool in hot weather.
This type of fan is actually very easy to build, only requiring a few parts.
To build this type of fan, the components needed are:
- 3V DC Motor
- Plastic Propeller
- 2 'AA' Batteries
- Battery Holder (optional)
The first part which we need is an electric DC motor. A DC motor spins when it is fed sufficient DC voltage. The reason we must use a DC motor, not an AC, is because we are powering the motor through batteries. Batteries supply DC voltage. Therefore, we must use a DC motor. And not only do we need is a DC motor but we need it to be a 3V DC motor. This is a DC motor which is powered by 3 volts. The reason why we need it a 3V motor is because we are going to use 2 'AA' batteries to power the motor. 2 'AA' batteries, in series, supplies 3 volts, since each battery supplies 1.5 volts each. If we chose a motor that needed more voltage, the 2 'AA' batteries would not be able to supply sufficient voltage to power it. For example, if we chose a 6V DC motor, 2 'AA' batteries, supplying 3 volts, is obviously not enough. In that case, we would need 4 'AA' batteries to power the motor. We don't want to use too many batteries when designing an electronic product. We want the design to be as efficient as possible, therefore, we would it ideally to be of low power. The lower the power needed, the less batteries are needed to power it. Therefore, a user will be happier with this than if they needed a bunch of batteries.
The next part which we need is a plastic propeller.
This is a plastic unit which goes over the shaft of the DC motor. When the motor receives sufficient power, it will spin. When the plastic propeller is attached to the shaft, it spins, since it's attached to the shaft. In turn, the propeller moves air and blows air into the face of the user, who needs to be cooled from the hot weather.
Plastic propellers can be obtained from Allelectronics- Plastic Propeller.
The last part which is needed are the 2 'AA' (double A) batteries. Each battery supplies 1.5 volts. When placed in series,
in total, they supply 3 volts. This is the amount of voltage needed to power a 3VDC motor.
This is necessary to power the DC motor, so that its shaft can spin, which in turns spins the plastic propeller.
Complete Electric Fan Circuit
When we put the complete circuit together, it will look something like the circuit below:
This circuit now acts as a fan. The batteries supply DC voltage to the DC motor, which powers it. Since the motor is now receiving sufficient power, its shaft will spin. This will spin the plastic propeller attached to the shaft.'
It's a very basic circuit. This is how handheld fans work. To give it an on-off button, then you would just attach a switch
from the batteries to the motor. This would allow a user to switch it on, then off when not in use.