Solving the "Singing" 48V Power Module in a Server Rack

Case Study: Taming Annoying Acoustic Noise in Power Modules 🔇 A client's industrial power module was emitting a high-pitched "singing" or buzzing sound under load—a classic case of inductor acoustic noise. This phenomenon, often caused by magnetostriction and winding vibration, is more than just an annoyance. It signals energy loss and can raise reliability concerns. Our engineered solution focused on the root cause: ✅ Material Science: Switched to a specialized ferrite core composition with lower magnetostriction. ✅ Advanced Process: Implemented vacuum impregnation with a high-performance epoxy to securely lock the windings and dampen vibration. ✅ System-Level Synergy: Worked with the client's team to slightly adjust the switching frequency, moving it away from the sensitive audio range. The result? Audible noise was eliminated, and the project moved smoothly into high-volume production. Have you encountered similar "singing" inductors in your #UPS, #PowerSupply, or #SolarInverter designs? What was your solution? Share your experiences in the comments! #Engineering #CaseStudy #Magnetics #PowerElectronics #EMC #HardwareDesign #Reliability #Manufacturing #[IKP electronics]

Unexpected Resonances – EMI Filters vs. Converter Control Loops: Sometimes the hardest problems in power electronics aren’t inside the converter itself, but in how it interacts with its environment. A classic example: resonances between EMI filters and converter control loops. The issue: *EMI filters add extra poles and zeros into the system. If the converter’s control loop isn’t designed with this in mind, their interaction can create unexpected resonances. *The result? Oscillations, instability, failed compliance tests, or strange field failures that are hard to reproduce. How to predict and damp: *Model the input impedance of the converter and the output impedance of the EMI filter – instability often arises when the two are comparable. *Use Middlebrook’s criterion as a design guideline. *Add damping networks (RC snubbers, resistive damping in filter capacitors, or active damping). *Validate with frequency response analysis (FRA), not just time-domain testing. Lesson learned: An EMI filter is not just an add-on for compliance – it becomes part of the control system. Treating it as such early in design saves painful debugging later.

EMI filters are not passive “bolt-ons” for compliance, but active participants in the system’s dynamic behavior. Better treat EMI filters as part of the control system early on.

High Power Density is a Trend — But Balance is the True Goal ⚡ In test power supplies, power density has become a major focus. Packing more kilowatts into fewer liters means better space utilization and efficiency — a clear advantage for R&D labs and system integration. But density alone is not enough. A truly robust solution must also balance performance and long-term reliability. Without this balance, higher density can quickly turn into higher risk. In practice, high-density designs must be supported by advanced capabilities, such as: 🔎 Four-quadrant operation → enabling bidirectional power flow for complex test scenarios 🔎 Programmable waveforms with feedback → simulating diverse conditions with high accuracy 🔎 Modular scalability → supporting multi-unit parallel connection and future expansion 🔎 Integrated AC source + load design → reducing system complexity, cabling, and cost 🔎 Fast dynamic response → ensuring precise performance in demanding applications An example is the ActionPower PRE20 Series, which integrates 22 kVA in just 3U (≈133 mm) — reaching nearly 950–1100 W/L, a level that stands among the industry’s best. Importantly, this density is achieved together with dynamic performance, functional integration, and stability, making it suitable for advanced applications like battery simulation, grid emulation, and high-end validation. 👉 In the end, high power density matters — but true engineering excellence lies in achieving density, performance, and reliability together. #HighPowerDensity #PowerTesting #Electronics #ActionPower

𝐒𝐰𝐢𝐭𝐜𝐡𝐢𝐧𝐠 𝐫𝐞𝐠𝐮𝐥𝐚𝐭𝐨𝐫 𝐟𝐮𝐧𝐝𝐚𝐦𝐞𝐧𝐭𝐚𝐥 switching regulator is a highly efficient power supply circuit that converts DC voltage by rapidly switching a power transistor on and off, using an inductor to store and transfer energy and a capacitor to filter the output voltage. Its core components are a switch, an inductor, a diode, and a capacitor, which allow it to regulate voltage efficiently, achieve high power density, and generate output voltages that are higher, lower, or of a different polarity than the input voltage.  Switching regulators are increasing in popularity because they offer the advantages of higher power conversion efficiency and increased design flexibility(multiple output voltages of different polarities can be generated from a single input voltage). Buck—used to reduce a DC voltage to a lower DC voltage. Boost—provides an output voltage that is higher than the input. Buck-Boost(invert)—an output voltage that is generated opposite in polarity to the input. Flyback—an output voltage that is less than or greater than the input can be generated, as well as multiple outputs.  Push-Pull—A two-transistor converter that is especially efficient at low input voltages. Half-Bridge—A two-transistor converter used in many offline applications. Full-Bridge—A four transistor converter(usually used in offline designs) that can generate the highest output power of all the types listed.

⚡ Active or Passive Component: Do You Think You Know the Difference? In this 2nd post of my series on PID control in electronics, I propose to look at this distinction from a much more practical angle. We all learn that: • 🔹 A passive component consumes energy (resistor, lamp, capacitor…). • 🔹 An active component uses a power supply to amplify or generate a signal (op-amp, transistor…). Simple, right ? Well… not really. 👉 So how can a passive circuit perform the same function as an active one, even though their nature is completely different? 🤔 When we apply this difference to an electronic PID, the impact is immediate: • ⚙️ Passive → simple, cost-effective… but inevitable losses. • ⚙️ Active → amplification, better precision… but watch out for saturation! ❗ Before designing a PID, don’t forget to: 1️⃣ Study the system stability (open-loop and closed-loop) 2️⃣ Calculate the P, I, and D coefficients (tuning) 3️⃣ Then build the circuit. 🎁 In this post, I share with you a practical document that includes: • Simple & beginner-friendly guide to designing P action in electronic. • LTspice simulations to visualize the electronic parameters. • Falstad demos to test passive vs. active in real time. 💬 And you? Do you know how to reduce voltage drop in a purely passive circuit (at least for small loads) 🤔❓ 📌 Additional resources: 👉 Part 1 - Intro to PID controller : https://lnkd.in/enD9aMhq 👉 Falstad Demo (Passive Implementation) : https://lnkd.in/eGewaKQY 👉 Falstad Demo (Active Implementation) : https://lnkd.in/eJyndKS6 #Electronics #Automation #Engineering #PID #Controller #ControlSystems #EmbeddedSystems #LTspice #Falstad

Power Transformer Turns Ratio (TTR) Test 🎯 Purpose To verify that the actual winding ratio (HV:LV turns) matches the design/nameplate ratio. To ensure correct vector group and polarity. To confirm tap-changer correctness across all tap positions. This test is critical before energization — a wrong ratio or vector group can cause severe circulating currents or parallel operation failure. Test Connections Equipment: Turns Ratio Tester (TTR) (e.g., Megger TTR, DV Power TRT, Omicron CPC100 with TTR module). Wiring Setup: 1. Connect the H terminal of TTR kit to HV bushing terminals of the transformer. 2. Connect the X terminal of the kit to LV bushing terminals. 3. If a tertiary (Δ) winding is present, connect accordingly to verify vector group. 4. Ensure transformer is isolated and discharged before connection. Principle: TTR kit applies a low AC voltage (~80–100 V) to one winding (usually HV) and measures the induced voltage on LV. Ratio = (Applied Voltage / Induced Voltage). Procedure 1. Select the tap position (start from first tap). 2. Apply test voltage through TTR. 3. Record: Ratio (HV/LV) Phase angle error Deviation from nameplate 4. Repeat for middle tap and last tap (plus all in between for OLTC). 5. Compare readings with nameplate ratio and factory test report. Acceptable Readings (IEC / IEEE Standards) Ratio Error Tolerance: ±0.5% (IEC 60076 / IEEE C57). Phase Angle Error: should be < 40 minutes. Vector Group: must match nameplate (e.g., Dyn11, YNd1). If deviation exceeds limits → OLTC problem, wrong winding connection, or shorted turns. Results on Tap Positions 1️⃣ First Tap (Max Tap / Highest Voltage Tap) HV turns are maximum → ratio is highest. Induced LV voltage is lowest for a given applied HV. Ratio error should still be within ±0.5%. 2️⃣ Middle Tap (Nominal Tap) This is the reference point. Ratio must closely match nameplate ratio. Used for base comparison across taps. 3️⃣ Last Tap (Min Tap / Lowest Voltage Tap) HV turns are minimum → ratio is lowest. LV induced voltage is highest. Current in LV winding will be slightly higher at this tap when energized, but for TTR test (low voltage applied), only the ratio matters. ⚡ Important Field Notes Symmetry: All three phases must show nearly identical ratio values; large deviation in one phase suggests winding deformation or OLTC issue. OLTC Jumps: If the ratio suddenly shifts at a particular tap, the OLTC diverter switch is faulty. Vector Group Check: TTR kits can automatically detect vector group; mismatches are often due to wrong bushing labeling or internal misconnection. ✅ Summary Connect TTR kit → HV side (H terminals), LV side (X terminals). Measure ratio at 1st, middle, and last taps. International standard: ratio error ≤ ±0.5%. Expect: Highest ratio at first tap Nominal ratio at middle tap Lowest ratio at last tap Abnormal readings → suspect OLTC, winding, or vector group issues.

What is ElectroStatic Charge? Electrostatic charge, commonly referred to as static electricity, represents an electric charge at rest. It arises from the imbalance of electrical charges on a material's surface or within its structure. Let's delve into this concept in greater detail… Click below to read and learn more! #ESD #ESDDamage https://lnkd.in/dGuU4cQY

Hello connectors , I have recently completed a mini project - H Bridge of motor driver , ⚡️ I commenced with breadboard connections , with a basic circuit diagram I made connections and instead of motor I have used LED to check the output .✅ Components used : Led PNP and NPN transistor ( each 2) Resistor (6) 📌Transistors : • Act as electronic switches to control the current path. • Four are arranged in an H-shape to form the H-Bridge. • When certain pairs are switched ON, current flows through the motor in one direction (forward), and when the opposite pair is ON, current flows in the other direction (reverse). 📌Resistors : • Used at the base of each transistor. • They limit the base current going into the transistors, protecting them from damage. • Ensure proper switching (not too much or too little current). 🔹 How They Are Used (Working Principle) This H-Bridge has two control inputs: A and B. 📌• Case 1: A = HIGH, B = LOW • Left-top transistor (Q1) and Right-bottom transistor (Q4) turn ON. • Current flows VCC → Q1 → Motor → Q4 → Ground. • Motor rotates in one direction (say, clockwise). 📌• Case 2: A = LOW, B = HIGH • Right-top transistor (Q2) and Left-bottom transistor (Q3) turn ON. • Current flows VCC → Q2 → Motor → Q3 → Ground. • Motor rotates in the opposite direction (anticlockwise). 📌• Case 3: A = B = LOW • All transistors OFF → Motor stops. 📌• Case 4: A = B = HIGH • Risk of short circuit (both top and bottom of one side conduct) Instead of Motor I have used LED’s, ✅This project helped me to understand deeply about the working of H bridge and the advantages of them . 🎖️ through this project , I strengthened my foundation . #electronics #miniprojects #importanceofHbridge #engineering #electrical

Concepts for realizing High-Voltage Power Modules. Embedding of power electronic components provides a large benefit in terms of reliability, volume reduction and electrical performance. Direct copper connection and the resulting short connection length lead to a significant reduction of parasitic inductance, resulting in improved switching behavior and switching losses. Proper thermal and electrical design is a key enabler for such high performance power modules.