A Comprehensive Guide to Designing a 12V DC to 220V AC Inverter Circuit & PCB
You need an inverter to convert low-voltage DC (Direct Current) power, which is commonly received from a battery or solar panel, into high-voltage AC (Alternating Current) electricity, which is compatible with conventional home equipment. In this manual, we'll look at the design and assembly of a PCB (printed circuit board) and a 12V DC to 220V AC inverter circuit. This article will provide you helpful tips whether you're an electronics enthusiast or looking for a dependable power supply during crises.
Before getting into the circuit design, let's establish a list of the fundamental parts required to build a 12V DC to 220V AC inverter.
Transformer
MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors)
Capacitors
Resistors
Diodes
Heat sink
PCB (Printed Circuit Board)
Inductor
Voltage regulator
Cooling fan (optional)
Design of a circuit
Step-up Transformer: The main winding of the transformer needs to be built for a 12V input, and the secondary winding needs to be built for a 220V output. Based on your needs, pick a transformer with a suitable power rating.
Four MOSFETs should be used to build an H-bridge in the MOSFET-Based H-Bridge design. By switching the polarity across the transformer, the H-bridge enables the transformation of DC electricity into an AC waveform.
Add capacitors across the transformer's output terminals as a filter to tame harmonics and smooth the output waveform.
Protection circuitry: Provide freewheeling routes for the inductive load as well as diodes to safeguard MOSFETs from reverse current.
Integrate a voltage regulator circuit to preserve a constant output voltage.
If necessary, include a cooling fan and heat sink in your cooling system.
PCB Design:
Schematic Creation: Begin by drawing a schematic diagram of the inverter circuit using a suitable software tool such as EagleCAD, KiCAD, or Altium Designer. Ensure that all the components are correctly connected and labeled.
PCB Layout: Transfer the schematic into the PCB layout software. Arrange the components in an organized and optimized manner, taking care of component clearances and signal traces.
Trace Routing: Route the traces carefully, ensuring appropriate thickness and width to handle the current and voltage requirements of the circuit. Place ground and power planes to minimize noise and provide stable reference voltages.
Design Rule Check (DRC): Perform a DRC to verify the layout against design constraints, such as clearances, minimum trace widths, and other manufacturing specifications.
Gerber File Generation: Generate Gerber files from the PCB layout software, which contain the necessary information for PCB fabrication.
PCB Fabrication: Send the Gerber files to a PCB manufacturer or use a DIY approach, such as etching, to fabricate the PCB.
Assembly: Once you have the fabricated PCB, proceed with soldering the components onto the board, following best practices for soldering and component placement.
Explanation of the circuit diagram:
DC Input: Connect the positive terminal of the +12V DC power supply to the input side of the inverter circuit.
Fuse: Place a fuse in series with the input to protect the circuit from excessive current.
Power Switch: Add a power switch to control the supply of power to the inverter.
Transformer Primary Winding: Connect the primary winding of the step-up transformer to the power switch.
MOSFET H-Bridge: Construct an H-bridge configuration using four MOSFETs, with their respective gates connected to control circuitry.
Filter Capacitors: Connect capacitors across the output terminals of the transformer to smooth out the output waveform.
Protection Diodes: Integrate diodes across each MOSFET to protect them from reverse current and provide freewheeling paths for the inductive load.
Voltage Regulator: Include a voltage regulator circuit to maintain a stable output voltage.
Cooling System: Optionally, add a cooling system such as a cooling fan and heat sink to prevent overheating of components.
AC Output: Connect the secondary winding of the transformer to the AC output terminals.
Load: Connect the desired load (e.g., household appliances) to the AC output terminals.
Safety and testing
After putting the circuit and PCB together, it's important to carry out careful testing and follow safety protocols:
Make sure the output waveform resembles the intended AC waveform by testing it with an oscilloscope.
To make sure they adhere to the necessary criteria, check the output voltage and frequency.
To evaluate the inverter's performance under various operating situations, use load tests.