Power net portal is a special schematic object used to define a power or ground net. Power ports allow you to conveniently indicate a power net at any location in the design. Power nets of the same designator automatically connect throughout your design #portal #power
A generic fixed inductor for rapid developing circuit topology. *You can now change the footprint and 3D model at the top level anytime you want. This is the power of #generics
@copilot I need your help in Designing a system to control the power (Wattage) delivered to a resistive load (RL) using MOSFETs, with an input of either 28VDC or 230VAC, and incorporating closed-loop control with a sensor, managed by a microcontroller unit (MCU) like an STM32,
Sure, I'd be happy to guide you through the process. Since the complete design could be complex, let's break it down into several steps:
DC/AC to DC Conversion: For the 230VAC case, you will need a rectifier (bridge or full-wave) followed by a filter capacitor. This will convert your AC voltage to DC. With 28VDC, you can omit this part.
Voltage regulation: The MCU and sensor will require certain voltage levels to operate, and therefore a voltage regulator should be implemented. For instance, the STM32 operates at 3.3V, so a 3.3V regulator such as the LM1117 should be used.
Power Control Element: A MOSFET is a great choice for control of power to the resistive load. You could use an N-Channel MOSFET like the IRF520, which will be controlled by a PWM (Pulse Width Modulation) signal from the MCU.
Sensor: To maintain wattage control, a current sensor can be used in series with the load to provide an analog voltage to the MCU corresponding to the current flowing through the load. An example of such a current sensor would be the ACS712. We can then calculate the power using the basic formula P=VI where we already know the voltage is either 28V (or rectified 230V) and the current is measured by the sensor.
Components and Connections:
Full-Wave Rectifier (If using 230VAC): Connect 230VAC to Rectifier AC (in), then connect Rectifier DC (out) to Filter Capacitor C1.
Filter Capacitor (If using 230VAC): Connect C1 (out) to R_Load.
Voltage Regulator: Connect Input to 28VDC supply (or C1 out if 230VAC is used), and Output to Microcontroller Power Pin on the STM32.
IRF520 MOSFET: Connect Gate Pin to Microcontroller PWM Pin, Source Pin to Ground, and Drain Pin to one side of the Resistive Load (RL).
Current Sensor ACS712: Connect it in series with your Load and power supply. Connect the Output to an ADC (Analog to Digital Converter) pin on the STM32.
STM32 MCU: Connect ADC Pin to ACS712 output, and PWM Pin to Gate of MOSFET.
Remember that your specific connections may vary depending on your chosen MCU.
Hope this helps you to start your project. Please feel free to ask if you have any questions or any specific requirements.
Sure, I'm more than happy to assist you in arranging the components for your project. However, I should note that while I can't physically intervene, I can certainly propose a guide with a sequence for organizing your schematic.
Voltage Source: Place your 28VDC or 230VAC power supply source to the left side of your schematic for a traditional left-to-right flow.
AC to DC Conversion: If you're using 230VAC, position the rectifier next to the source, and then position the filter capacitor right after it to handle the AC to DC conversion.
Voltage Regulator: Position the voltage regulator next to the DC source (this will be the output from filter capacitor if a 230VAC source is used or the 28VDC source).
Microcontroller (MCU): Place the MCU (STM32) beside the voltage regulator. This will make it clear that the MCU is powered by the output of the voltage regulator.
Power MOSFET: Position the MOSFET so that the gate terminal (which will be connected to a PWM output from the MCU) is placed directly to the right of the MCU.
Load (Resistor RL): Right of the MOSFET, place the resistive load (RL). RL goes to the Drain terminal of the MOSFET and to one side of the current sensor.
Current Sensor: Position the ACS712 such that the load (RL) and the other terminal (ACS712) are connected to the power supply return line.
Stick to arranging your lines vertically or horizontally and keep the crossing of the lines to a minimum, for a clear schematic. Remember to label each component distinctly for the convenience of anyone who views your schematic. Lines connecting components represent wires or traces on your PCB.
Do keep in mind to arrange all your components where it's easiest for you, the order given is merely a guideline, and different individuals may prefer different component arrangements according to their work processes.
1y
Hi! Iām copilot. Think of me like an experienced electrical engineer that can he...
Hi! Iām copilot. Think of me like an experienced electrical engineer that can help you brainstorm ideas, debug problems, research components, and even make wiring connections for you. Ask me questions like:
@copilot I'm designing a PCB for a medical device that measures heart rate and temperature. Can you give me the list of components I will need?
@copilot How would I connect these parts to make the LED flash at 1kHz?
@copilot can you choose 4 digital pins on the ATMega328P-AU that I have here to use as GPIO given that I am already using some pins for reset, the external clock, UART, and I2C.
Reach me at any time by tagging me on comments or in the chat with my handle, @copilot.
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Passive Components
Resistor Power Rating
Beta
Checks that the power traveling across a given resistor is under its rating with 50% headroom.