Understanding Soft-Start Circuits in Power Electronics

Shunt Resistor – A Simple Component with a Powerful Role In electronics, sometimes the smallest components do the biggest jobs. A shunt resistor is one such example — crucial for current measurement and circuit protection. What is a Shunt Resistor? A low-value precision resistor placed in parallel (or sometimes in series) with a circuit path to create a measurable voltage drop that is proportional to current. Why It’s Important: 1️⃣ Current Sensing – Converts current into voltage (using Ohm’s Law). 2️⃣ Protection – Prevents overcurrent by enabling monitoring/control. 3️⃣ Accuracy – Used in precision power supplies, battery management, and energy meters. Key Considerations in Design: Resistance Value (mΩ range) – Must be low enough to minimize power loss but high enough to generate measurable voltage. Power Rating – Handles heat dissipation under high currents. Temperature Coefficient – Stability matters in precision systems. Real-World Applications: Battery management systems (BMS) in EVs. Power monitoring in embedded devices. Industrial automation for current feedback. Takeaway: The shunt resistor may look tiny, but it’s the eyes of the circuit — allowing us to “see” current and keep systems safe and efficient. #Electronics #CircuitDesign #ShuntResistor #Engineering

Every time you de-energize a DC relay coil, you create a high-voltage spike. This spike, caused by the coil’s stored magnetic energy, can damage semiconductors, shorten relay life, and introduce electrical noise into your panel. 🔍 What’s Happening Technically: A DC coil acts like an inductor, storing energy in its magnetic field. When the control signal drops, the collapsing field forces current in the opposite direction, generating a voltage spike (often >200V). Without suppression, this spike stresses transistors, microcontrollers, and other sensitive circuits. 🔧 Solutions Engineers Use: 1️⃣ Flyback Diode (Most Common): Placed across the coil to safely dissipate energy. 2️⃣ RC Snubber: Handles high-frequency transients, great for AC relays. 3️⃣ TVS Diode or Varistor: Best for high-speed switching or critical protection. 📈 Benefits: Extends relay life by reducing arcing. Protects PLC outputs, HMI controllers, and power electronics. Improves system reliability and reduces downtime. 💡 Engineering Takeaway: A $0.05 diode can save a $500 controller. Always design with suppression in mind! #RelayProtection #ElectricalEngineering #PLCProgramming #IndustrialAutomation #PanelDesign #FlybackDiode #ControlSystems

Every time you de-energize a DC relay coil, you create a high-voltage spike. This spike, caused by the coil’s stored magnetic energy, can damage semiconductors, shorten relay life, and introduce electrical noise into your panel. 🔍 What’s Happening Technically: A DC coil acts like an inductor, storing energy in its magnetic field. When the control signal drops, the collapsing field forces current in the opposite direction, generating a voltage spike (often >200V). Without suppression, this spike stresses transistors, microcontrollers, and other sensitive circuits. 🔧 Solutions Engineers Use: 1️⃣ Flyback Diode (Most Common): Placed across the coil to safely dissipate energy. 2️⃣ RC Snubber: Handles high-frequency transients, great for AC relays. 3️⃣ TVS Diode or Varistor: Best for high-speed switching or critical protection. 📈 Benefits: Extends relay life by reducing arcing. Protects PLC outputs, HMI controllers, and power electronics. Improves system reliability and reduces downtime. 💡 Engineering Takeaway: A $0.05 diode can save a $500 controller. Always design with suppression in mind! #RelayProtection #ElectricalEngineering #PLCProgramming #IndustrialAutomation #PanelDesign #FlybackDiode #ControlSystems

Every time you de-energize a DC relay coil, you create a high-voltage spike. This spike, caused by the coil’s stored magnetic energy, can damage semiconductors, shorten relay life, and introduce electrical noise into your panel. 🔍 What’s Happening Technically: A DC coil acts like an inductor, storing energy in its magnetic field. When the control signal drops, the collapsing field forces current in the opposite direction, generating a voltage spike (often >200V). Without suppression, this spike stresses transistors, microcontrollers, and other sensitive circuits. 🔧 Solutions Engineers Use: 1️⃣ Flyback Diode (Most Common): Placed across the coil to safely dissipate energy. 2️⃣ RC Snubber: Handles high-frequency transients, great for AC relays. 3️⃣ TVS Diode or Varistor: Best for high-speed switching or critical protection. 📈 Benefits: Extends relay life by reducing arcing. Protects PLC outputs, HMI controllers, and power electronics. Improves system reliability and reduces downtime. 💡 Engineering Takeaway: A $0.05 diode can save a $500 controller. Always design with suppression in mind! #RelayProtection #ElectricalEngineering #PLCProgramming #IndustrialAutomation #PanelDesign #FlybackDiode #ControlSystems

🔌 How 6 Diodes Turn AC into DC 💡 Ever wondered how industrial drives get smooth DC from rough AC? The answer lies in the Three-Phase Bridge Rectifier — a core component in modern power electronics. 🔧 Here's a breakdown to spark your engineering mind: ✅ 3-phase AC input (R, Y, B) enters the rectifier ✅ 6 diodes arranged in a bridge configuration ✅ Two diodes conduct at any moment — one positive, one negative ✅ Conduction happens in 60° segments to maintain continuity ✅ Output: 6-pulse DC waveform with reduced ripple ✅ Efficiency: Higher than single-phase systems ✅ Applications: – Motor drives – DC link converters – Industrial automation systems #EletrosoniGlobal #Semiconductors #SemiconductorIndustry #ChipDesign #ICDesign #ASIC #SoC #Fabless #ChipManufacturing #Nanoelectronics #VLSI #EDAtools #EmbeddedSystems #Microelectronics #AIChips #RFDigital #AppleSilicon #FoundryServices #WaferFabrication #SemiconductorDesign #SemiconductorEngineering #ChipInnovation #CleanRoomTech #TechHardware #AdvancedPackaging #SemiconductorSupplyChain

🔋 The Role of the Double Pulse Test in Medium-Voltage NPC Converters ⚡ In medium-voltage drives, the three-level Neutral Point Clamped (NPC) inverter is one of the most widely adopted topologies thanks to its efficiency, lower harmonic content, and reduced device stress. However, achieving reliable operation requires careful evaluation of the switching behavior of each device in the phase leg. 👉 This is where the double pulse test (DPT) becomes essential. 🔎 Why it matters - Datasheet values are obtained under ideal test setups with minimal parasitics. - In real converter prototypes, busbar inductances, commutation paths, and gate driver design significantly affect switching behavior. - The DPT allows engineers to validate devices inside the actual NPC configuration, ensuring accurate performance assessment. 📊 Key insights from DPT in NPC converters - Turn-on and turn-off losses → define the thermal design of the power cell. - Overvoltage at turn-off → influenced by leakage inductance and di/dt. - Reverse recovery of clamping and freewheeling diodes → impacting efficiency and EMI. - Asymmetric stress on inner vs. outer switches → a critical characteristic of NPC topologies. ⚙️ Gate driver tuning DPT enables the fine adjustment of gate resistance and driver strategies, balancing switching speed, overvoltage, and efficiency — essential for medium-voltage applications where reliability is non-negotiable. 🔑 In summary, for MV NPC converters, the double pulse test is not optional — it is the cornerstone for developing safe, efficient, and robust medium-voltage drives. 📚 Selected References [1] A. Dias, J. A. Alves, Experimental tests to evaluate the electrical behavior of medium voltage power cells with adjustable speed drives, WEG Drives & Controls. [2] J. Korhonen et al., Double pulse test method for neutral point clamped inverter switches at the nominal rating while using only half of the nominal DC link voltage, IEEE SPEEDAM, 2022. [3] R. Jakob et al., 3-Level High Power Converter with Press Pack IGBT, EPE, 2005. #PowerElectronics #MediumVoltage #NPC #IGBT #DoublePulseTest #MVDrives

⚡Why does a diode allow current in one direction but block it in the other? The answer lies in its I-V characteristics! 📉⚡ 🔁 Understanding the Current-Voltage (I-V) curve of a diode is crucial for designing rectifiers, regulators, and switching circuits. Let’s break it down! 📌 Key Regions of the I-V Curve ✅ Forward Bias Region (+V, +I) ⤷ Small current flows until threshold voltage (Vₜ) is reached ⤷ Silicon diode: ~0.7V | Germanium diode: ~0.3V | LEDs: ~1.8V - 3.5V ⤷ After Vₜ, current rises exponentially ✅ Reverse Bias Region (-V, ~0I) ⤷ Minimal leakage current flows (almost no conduction) ⤷ Acts as an open circuit ✅ Breakdown Region (-V, High -I) ⤷ If reverse voltage exceeds limit, breakdown occurs ⤷ Zener diodes are designed to operate in this region for voltage regulation 📊 Where Are These Curves Used? ⤷ Rectifier Circuits → Convert AC to DC ⤷ Voltage Regulators → Maintain steady voltage (Zener diodes) ⤷ LED Circuits → Light emission for indicators & displays ⤷ High-Speed Switching → Schottky diodes for fast response 💡 Choosing the right diode requires understanding its I-V curve! Engineers use this data to optimize circuit performance and efficiency. ➡ What’s your go-to diode for circuit design? Let’s discuss in the comments! 💬 ♻️ Repost to share with your network if you find this helpful. 🔗 Follow Ashish Shorma Dipta for posts like this. #ElectricalEngineering #Diodes #PowerElectronics #Semiconductors #CircuitDesign

Today’s focus was on the traditional mobile charger circuit. I explored how a step-down transformer, rectifier, filter, and voltage regulator work together to convert 230V AC into a stable 5V DC output – the backbone of mobile charging. Key Learnings: ⚡ Step-down transformer: Converts 230V AC → 9V AC ⚡ Bridge rectifier (D1–D4): Converts AC → pulsating DC ⚡ Filter capacitor: Smoothens DC output ⚡ Voltage regulator (7805 IC): Provides steady 5V DC ⚡ Bypass capacitor: Removes high-frequency noise I also looked at transformer design equations using Faraday’s Law of Electromagnetic Induction and the drawbacks of traditional chargers (heavy, bulky, less efficient). This naturally connects to SMPS (Switch Mode Power Supply) technology, which modern chargers use for compact size and higher efficiency. 💡 Takeaway: Even a simple mobile adapter holds deep engineering insights into power conversion and regulation. 👉 Up next in the challenge: exploring fast charging, wireless charging, and SMPS-based charger circuits in the coming days! #CircuitDesign #Electronics #LearningInPublic #ElectricalEngineering

7800 Series Voltage Regulators: 7805, 7812, 7824, etc For many years the 7800 or 78xx series linear voltage regulators, including the more popular versions of this series like the 7805, 7812, etc, were the most popular voltage regulator chips available and they were used in many electronic circuits, large and small. The 7800 series voltage regulators were very easy to use, they were cheap to buy, and they provided excellent performance. Although now they are a little dated, they can still be obtained very cheaply and provide excellent performance, and they often remain designated as "Active" components that are likely to remain available for many years to come. This makes them an ideal choice for many electronic devices and circuits, especially for the home constructor, etc. Not only was there the 7800 series of linear voltage regulators giving a positive output voltage, but there was also the complementary 7900 series regulators used for negative voltage lines. Basic 7800 series voltage regulator circuit The electronic circuit design using 7800 series voltage regulators is very easy. It is almost a matter of putting them in circuit: input, output and ground. Naturally there are a few additional electronic components that may be required to ensure the correct operation of the voltage regulator circuit. Points to note in the circuit: *     This capacitor is required to ensure the stability of the regulator. Normally if the smoothing capacitor for the rectifiers is close, then this can be omitted, but if there is any length of wire, then it must be included to ensure the circuit remains stable. **     This capacitor is in circuit to remove noise and transients. This is the basic circuit used for any 7800 series voltage regulator. It is very successful and requires no additional components beyond those shown for the basic operation. Read more: https://lnkd.in/gHmmpni #voltageregulator #7800regulator #circuitdesign #powersupplies #linearregulator

✅Day 259 of My Power Electronics Challenge 📘Topic: UVLO (Under-Voltage Lockout) – Protecting Power Circuits from Low Supply Risks ⚡ What Is UVLO? Under-Voltage Lockout (UVLO) is a vital feature in power electronics that monitors the supply voltage and disables or locks out switching regulators, drivers, or controllers if voltage falls below a safe threshold. This protection ensures systems never operate in regions that could lead to erratic behavior, data corruption, or device damage. 🔍 Why Is UVLO Essential? Prevents Malfunctions: Low supply voltage can cause MOSFETs, drivers, and ICs to turn on incompletely, resulting in overheating, faulty switching, or unpredictable logic. Protects Loads & Data: UVLO eliminates risk of unreliable signals or brown-out data loss in embedded and communication systems. Enhances Safety: Ensures converters, chargers, and automation systems operate only when the supply is within specification. ✅ Typical UVLO Implementations Integrated IC Feature: Built into most PWM controllers, gate drivers, voltage regulators, and power management ICs. Programmable Thresholds: Some designs allow tuning UVLO points for custom battery levels or supply rails. Digital/Analog Monitoring: Comparator or microcontroller-based circuits can implement adjustable UVLO for advanced systems. 📘 Design Tips Set the UVLO threshold above the device’s minimum safe operating voltage, considering load startup requirements. Validate lockout and recovery behavior with controlled supply ramps and oscilloscope. Use UVLO flags and interrupts for logging and fault diagnosis. Combine UVLO with overvoltage and brown-out protection for comprehensive resilience. 🔧 Applications Switching power supplies and DC-DC converters Motor drivers and inverters Battery-powered and portable electronics Industrial controllers, wireless modem and sensor nodes 🧠 Quick Tip: A missed UVLO setting can cause elusive, intermittent failures—always specify, simulate, and test this feature on every new design! 🌐 UVLO is key for making power electronics robust and reliable—not just against missed supply, but for all low-voltage risks. 🔖 #PowerElectronics #UVLO #UndervoltageLockout #VoltageProtection #Reliability #PWMController #DesignTips #EmbeddedSystems #CircuitTesting #100DayChallenge #Day259 #BatteryPowered #OmWaghmare