26. Group Assignment Week 10 - Output Devices¶
This week we are working on communicating an output device with our microcontroller. In the group assignment we are measuring the power consumption of an output device.
Group Assignment
- Measure the power consumption of an output device
Group Members:
Measuring Devices¶
In order to measure the power consumption of an output device we can make use of a number of measuring instruments and methods. The primary method that we can employ is to connect a current measuring instrument in series with our output device and calculate the power with the following equation.
Power = Voltage x Current.
Measuring Instruments
- Measuring current using a DC power supply
- Connecting an Ammeter in series.
- Using a powermeter.
In our lab we had the following options to measure the power consumption of our output device.
- DC Power Supply
- Multimeter as Ammeter.
DC Power Supply¶
Initially we started working with the DC power supply available in our lab, The DC power supply we have in our lab is the GW INSTEAK GPD3303D
Overview of the Power Supply
The GPD3303D is a 3-channel multiple output programmable linear DC Power Supply contain the superior technology and high quality which GW Instek had established through its long history of power supply design and manufacturing. The GPD series offers digital panel control, large display, bright LED indicators, high output resolution, 4 sets of setup memory, USB remote control and smart cooling fan control. Additionally, the GPD series provide easy operation, a wide selection of panel setting and operation, a wide selection of panel settings. All these features make the GPD series the most promising new comer in the power supply market. The knobs are digitally controlled, allowing fine or coarse volume setting. The key lock feature locks panel operations, preventing accidental changes of the setting which might lead damaging for the equipment’s. This GPD series can save and recall panel settings, these features which cannot offer by general power supplies.
- User-friendly operation, coarse/fine volume control
- Four sets save/recall
- Key-lock
- Output ON/OFF
- Smart cooling fan achieving low noise
- USB standard interface
- PC software and USB driver
- LabVIEW™ driver
The above informations were taken from: https://www.newark.com/gw-instek/gpd3303d/power-supply-3ch-30v-3a-programmable/dp/08R6425
The power supply has the following specifications:
- Power Supply Output Type: Programmable
- No. of Outputs: 3 Output
- Output Voltage Min: 0V
- Output Voltage Max: 30V
- Output Current Min: 0A
- Output Current Max: 3A
- Power Rating: 195W
- Supply Voltage Min: 100VAC
- Supply Voltage Max: 230VAC
- Manufacturer Warranty: -
- Product Range: GPD Series
We made the circuit connection of our board with output device connected to the power supply. However, in the course of measuring, the power supply was non-functional.
We tried connecting it to both the 230V and 120V power supply. However, it would not start. Therefore, we moved on to working with another method.
Multimeter as Ammeter.¶
Then we followed by using a multimeter as an Ammeter. To accomplish that we first put the Ammeter in current measurement setting and connect the ammeter in series with our output device. The circuit connection we made use of is shown below:
Figure: LED Load (Above), Motor Load (Below).
Using the multimeter as Ammeter in series, we switch the power supply and record the current drawn by the output device. In our group, we have two output devices in use namely a DC motor and LED. We connected the controller to the output device with one of the wire connected through the Multimeter.
The measured values of the power consumed by the output devices are shown below:
Power Consumption
Power consumed by LED: > 9mA
Power Consumed by Motor: > 90mA
Videos¶
The videos showing the measurement of power using Multimeter as Ammeter is shown in the video below: