Output Devices
Output Devices
Group Assignment
measure the power consumption of an output device
Group Assignment Workflow
For this week, we have decided to test various output devices, and for the first attempt, we have chosen a stepper motor. This is the properties of the motor we used (shown in the datasheet):
Current: 20mA
Voltage: 12V
Reference site
There are four main ways we can measure the electrical properties of the motor:
- Data Sheet - we can get the overall image of the device
- Scope. - not useful; not a good workflow; we are only able to measure Voltage and thus we have to calculate other values – e.g. current – on our own.
- Bench Power Supply - we can both supply and measure power that goes into the motor.
- Multi meter - most important; we can get each values separetely, rather than getting the overall combined value.
The image below shows how we connected the board to the Bench Power Supply.
In the image below, we are measuring current and voltage of the motor. In the process, we realized that the values that are written in the data sheet are avarage, most of the time, not the best or maximum values. Therefore, it is crucial to test and measure, rather than heavily relying on the information on the data sheet.
To measure current and voltage that solely goes to the motor, not other boards (e.g. Arduino UNO), we had to put the tips of the probs of the multi meter on the iron on the bottom side of the board.
Depending on the range of the voltage that goes into a chip, it is important to choose the right hole between these two: 20A MAX and mA on the multi meter.
We used the aligator clips (clamp jumpers) to measure current.
After this investigation, we got these values:
I = 0.12 A
V = 5.77 V
By using these, we calcualted Power (P).
P = I x V
P = 0.12 x 5.77
= 0.6924 Watt
In the table below, we show current (A) for each output device we tested over the week.
| name | output device | theory | measure |
|---|---|---|---|
| Hyunho | Grove-Water Atomization | Rating Voltage = 5.0V(DC) Max Current = 400mA Power consumption = 2W |
Rating Voltage = 5.0V(DC) Max Current = 180mA Power consumption = 0.9W |
| Yunjo | |||
| Jeonghwan | Stepper Motor(NEMA17) | Rating Voltage = 24.0V Max Current = 1700mA Power consumption = 40W |
Rating Voltage = 15.3V Max Current = 350mA Power consumption = 5.355W |
| Jihwan | peltier module | Rating Volt = 12V Max Currnet = 8A Power consumption = 92.1W |
Rating Volt = 12V Max Currnet = 3A Power consumption = 36W |
| Seokmin | |||
| Yunje | WS2812B | Rating Voltage = 5.0V Max Current = 500mA Power consumption = 2.5W |
Rating Voltage = 5.0V Max Current = 200mA Power consumption = 1W |