9. Output devices¶

This is the documentation of week 9 activity output devices by Ahmad Tijjani Ishaq and Muhammad Jidda.

As for our individual Assignment it can be found here Jidda and Ahmed

The group task for this weeks activity is to measure the power consumption of an output device

OUTPUT DEVICES¶

Output devices are essential components in various systems and technologies, converting electronic signals into tangible actions or displays. They play a crucial role in transforming digital information into physical outcomes that users can perceive and interact with.

Some examples of output devices are - DC Motor - Servo Motor - Stepper Motor - LCD Display - Speakers etc.

Group tasks¶

We measured the power consumpption of three DC motors 12v, 9v, and 5v dc motors.

Equipments

We used the following testing equipments: - Multimeter - DC Power supply

Multimeter¶

A multimeter, also known as a multitester or VOM (volt-ohm-milliammeter), is an electronic measuring instrument that combines several measurement functions in one unit. Here are some common types of measurements a multimeter can perform:

Voltage Measurement (Volts, V): Multimeters can measure both AC (Alternating Current) and DC (Direct Current) voltages. They are used to measure the voltage level of electrical circuits or components.
Current Measurement (Amperes, Amps, A): Multimeters can measure electrical current flow. They can measure both AC and DC currents in circuits, typically ranging from milliamps to amps.
Resistance Measurement (Ohms, Ω): Multimeters can measure the resistance of electrical components or circuits. This measurement helps in troubleshooting circuits, testing continuity, or determining the value of resistors.
Continuity Testing: Multimeters have a continuity test function that checks if there is a complete path for current flow between two points in a circuit. It typically emits a beep or shows a low resistance value when continuity is detected.
Diode Testing: Multimeters can test diodes to determine if they are functioning properly. They apply a small voltage across the diode and measure the resulting voltage drop to assess its forward bias.
Capacitance Measurement (Farads, F): Some advanced multimeters can measure capacitance, which is the ability of a component to store electrical charge. This measurement is useful in testing capacitors and analyzing electronic circuits.
Frequency Measurement (Hertz, Hz): Certain multimeters can measure the frequency of an AC signal. This is helpful for analyzing electrical waveforms and troubleshooting frequency-related issues.
Temperature Measurement: Some multimeters come with a built-in or external temperature probe to measure temperature in Celsius or Fahrenheit. This feature is useful for HVAC technicians, electricians, and engineers working with temperature-sensitive equipment.
Duty Cycle Measurement: Advanced multimeters can measure the duty cycle of a waveform, which represents the ratio of the time a signal is active to the total period of the waveform.
Inductance Measurement (Henries, H): High-end multimeters may also have the capability to measure inductance, which is the property of an electrical conductor by which a change in current induces an electromotive force in the conductor itself.

DC Supply¶

DC Power Supply¶

A DC (Direct Current) power supply is an electrical device that converts alternating current (AC) from a mains power source into a steady, continuous flow of direct current. DC power supplies are used in various applications across industries such as electronics, telecommunications, automotive, and manufacturing.

Types of DC Power Supplies:¶

Linear Power Supply: Linear power supplies use a transformer to step down the voltage from the mains power source and convert it to DC using rectifier circuits. They typically provide a stable output voltage but are less efficient and larger compared to other types of DC power supplies.
Switched-Mode Power Supply (SMPS): Switched-mode power supplies use high-frequency switching techniques to convert AC voltage to DC. They are more efficient and compact than linear power supplies and are commonly used in electronic devices such as computers, TVs, and mobile phones.
Bench Power Supply: Bench power supplies are versatile DC power sources commonly used in laboratories, workshops, and educational settings. They offer adjustable output voltage and current limits, allowing users to simulate various operating conditions for testing electronic circuits and components.

Key Features:¶

Output Voltage and Current Adjustment: DC power supplies allow users to adjust the output voltage and current to meet the requirements of specific applications.
Regulation: Good DC power supplies maintain a stable output voltage even when the load or input voltage changes. Voltage regulation ensures consistent performance and protects connected devices from voltage fluctuations.
Overcurrent and Overvoltage Protection: DC power supplies incorporate protection mechanisms to prevent damage to the connected load in case of overcurrent or overvoltage conditions.
Remote Control and Monitoring: Some DC power supplies offer remote control capabilities, allowing users to adjust settings and monitor performance remotely via computer interfaces or communication protocols.

Applications:¶

Electronics Testing and Development: DC power supplies are essential tools for testing and prototyping electronic circuits, powering components, and simulating real-world operating conditions.
Battery Charging: DC power supplies are used to charge rechargeable batteries in various devices such as smartphones, laptops, electric vehicles, and renewable energy systems.
Industrial Automation: DC power supplies play a crucial role in industrial automation systems, providing stable power to control circuits, sensors, actuators, and other equipment.
Telecommunications: DC power supplies power telecommunications equipment, including routers, switches, base stations, and communication towers.
Medical Devices: DC power supplies are used in medical devices such as MRI machines, ultrasound equipment, and patient monitoring systems, providing reliable power for critical healthcare applications.

Proceedure¶

To measure The power consumption of our various dc motors, We measured the current flow through them (when no load is connected and when they are at a stall) when they are connected to a power supply. We used both the multimeter and power supply device to do that.

Measurement¶

Using Power Supply - We connected The Possitive (Red) probe of the power supply to one terminal of our Dc motor and the other probe(black) to the other terminal. - We then switched on our DC supply and set the voltage to that of the motor. - The current drawn by the motor is then displayed on the current segment of the dc supply screen.

Using Multimeter - We connected the negative probe of our power supply (it could be battery but we used our DC supply) To one terminal of our DC motor - Then The possitive probe of our DC supply to possitive probe of multimeter - And lastly Negative probe of multimeter to the other terminal of our DC motor as illustrated in image below

Stall Current

Stall current is the current drawn when the DC motor is loaded to a complete stop. It is the maximum current that the DC motor can draw.

The measurement connection is similar as above be it with multimeter or with the DC supply.
When the motor is powered, we hold it to a complete stop and then take the measurement

Result and Conclusion¶

We obtained the following currents value for our three motors.

MM- Multi meter

DS- DC supply

Motor	No load Current (DS)	No load Current (MM)	Stall Current (DS)
12V DC	50mA	54mA	1.05A
9V DC	100mA	96mA	2.68A
5V DC	90mA	86mA	790mA

We Then proceed to calculate our power for each motor using the infamous power equation

P= I * V

Where:

P is power
I is current draw by the motors
V is the voltage supplied to the motors

we used the current values obtained from the DC Supply screen.

Motor	No load Current	Stall Current	No load Power(W)	Stall load Power(W)
12V DC	50mA	1.05A	0.6W	12.6W
9V DC	100mA	2.68A	0.9W	24.12W
5V DC	90mA	790mA	0.45W	3.95W

From The results obtained we can see that The power drawn when at stall is much more than that when no lad is applied. This implies that when a dc motor is loaded it draws more current increasingly.

Last update: April 6, 2024