Source: https://mokxi.com/learn/power-supply-design Updated: 2026-11-11 Electrical track Power supply design # Power supply design: from the wall to a battery pack Rectifiers and smoothing, linear regulators, a boost converter, LiPo charging and a battery gauge, each one measured on simulated meters. Free In your browser 2 courses, 27 lessons, about 13 hours Start free The voltage divider See the course Overview ## How you will learn it Every circuit needs power, and a bad supply causes more mystery bugs than bad code. Designing one well means knowing where the volts come from, what a regulator wastes as heat, and when a switching converter is worth the noise. Power and batteries builds a supply piece by piece and ends with a power bank and a charge gauge. Electronics basics covers the rectifier and capacitor that turn the wall into DC. Outcomes ## What you will learn - Turn AC into smooth DC with a rectifier and a capacitor. - Choose between a linear regulator and a boost or buck converter. - Charge a LiPo safely with a TP4056 and wire cells in series or parallel. - Measure a battery's voltage with a divider and show its charge. Your route ## The courses and lessons to take Every lesson opens in the editor right away, signed in or not, and the simulator checks each step. - Step 1 · 20 lessons · 10 h ### Electronics basics The rectifier, the capacitor and the divider. - The voltage divider Two resistors in a row split a voltage in a fixed ratio. Read the middle with a meter, change the ratio, and build a divider for a voltage you choose. - From the wall to DC: a rectifier and a capacitor One diode blocks the negative half of an AC wave, and a big capacitor fills the gaps. Watch AC turn into smooth DC, and see what a small capacitor or a heavy load does to it. Every lesson in the course - Step 2 · 7 lessons · 3 h ### Power and batteries Regulators, converters, charging and a power bank. - A voltage regulator: 9 V in, 5 V out A 7805 turns a 9 V battery into a steady 5 V: its three legs and two capacitors, the dropout when the battery runs down, the heat it makes, and an AMS1117 that needs far less headroom. - Charging a LiPo with a TP4056 A solar panel charges a LiPo through a TP4056 while an INA3221 and an LCD show every milliamp: why lithium needs a real charger, the 4.2 V limit, and what happens when the sun goes down. - A boost converter: one cell to 12 V An MT3608 boost module turns one 4 V lithium cell into 12 V for a lamp, and keeps it at 12 V as the cell runs down: how a boost converter trades amps for volts, and why it cannot step down. - Boss project: a power bank with a charge gauge Put it all together: a lithium cell charged from USB by a TP4056, boosted to 5 V by an MT3608 for a gadget, and an Uno showing the charge on an LCD and a traffic light. Every lesson in the course Keep going ## Guides and tools on the same subject Lab ### Diodes and rectifiers lab Open it Guide ### LM2596 buck converter Open it Simulator ### Voltage regulator simulator Open it Track ### Electrical track Current and voltage you can see, then transistors, op-amps, filters, power and PCBs. Every circuit runs in a real circuit simulator in your browser. See the whole track Questions ## Questions people ask Linear regulator or switching converter? A linear regulator is simple and quiet but turns the extra voltage into heat. A switching converter wastes far less but adds noise. The course measures both so you can see the trade. Is it safe to learn about LiPo charging this way? Yes. The simulator shows what a charger does at each stage, with no risk. On a real bench, always use a proper charger module like the TP4056. Does this cover switching power supply design? It covers boost converters and why they work. Deeper switching design is planned for a power electronics course in the electrical track.