Power supply schematics

Build a simple 4.7 volt charging circuit to safely power your mobile phone's 3.6 volt battery, utilizing a BD139 transistor and a 4.7 volt Zener diode for optimal slow charging efficiency and battery health.... [read more]

Build your own intelligent 9V Ni-Cad charger with a 555 timer and achieve perfectly charged batteries every time. This innovative circuit, utilizing components like a 555 timer and a 4.7V Zener diode, allows for automatic charging of 6V and 9V Ni-Cad batteries, ensuring optimal performance and preventing overcharging.... [read more]

Build a robust NiCd battery charger capable of charging up to 7 batteries and unlock limitless potential with a 25V input. This innovative design includes reverse polarity protection and safeguards against discharge, empowering you to create a reliable charging solution.... [read more]

Power your devices anywhere with this compact 5V supply, delivering 660mA for charging iPods, MP3 players, and USB accessories. This efficient switch-mode regulator minimizes heat and provides reliable power on the go.... [read more]

Build your own portable mobile charger with four 1.5V pen cells, delivering up to 1.5 Amps and charging your phone three to four times while traveling. This innovative circuit, featuring a BC548 transistor and Zener diode, creates a powerful solution for charging your mobile device without access to AC power.... [read more]

Build your own affordable 7.2V mobile phone charger with this innovative circuit design. This schematic utilizes readily available components – including an LM7806 regulator and a 9VAC transformer – to create a powerful and reliable charging solution, perfect for boosting your projects and ensuring your devices are always powered up.... [read more]

Build a portable cellphone charger and extend your travel adventures with this simple circuit, delivering power in just two to three hours. This innovative design utilizes a 12V battery and a carefully calibrated circuit to replenish your phone's battery, ensuring you stay connected on the go.... [read more]

Build a powerful, versatile universal charger perfect for car and portable device charging, boosting your electronics projects with this innovative schematic. This circuit transforms a standard mains adapter into a customizable charger, ideal for NiCd and NiMH batteries, and allows you to charge phones, toys, MP3 players, and more. Select from 5 adjustable charge currents and monitor charging progress with the integrated LED indicator. Create your own customized charger today!... [read more]

Optimize your model aircraft batteries with this innovative charger, designed for precise Lithium-Polymer cell charging and maximizing their performance. Achieve up to 97% of your cells' rated capacity through a controlled 600mA charge, safeguarding against damage and ensuring a powerful, reliable boost for your aircraft.... [read more]

Build a robust and intelligent Peltier cooler charging circuit with advanced protection features. This innovative design seamlessly switches between vehicle and SLA battery power, utilizing a 2-step charging process and incorporating a resettable PTC thermistor, a low-voltage disconnect, and inline fuse for ultimate battery safeguarding and optimal cooling performance.... [read more]

Safeguard your car battery with this innovative circuit, utilizing a 3-terminal regulator (REG1) providing 8V power and a high-current Mosfet to control charging, preventing overcharging and extending battery life. This system employs a 555 timer and a zener diode to ensure precise charging, indicated by LED2, offering a reliable and motivating solution for your automotive needs.... [read more]

Build a robust and reliable mobile charger with precise current and voltage regulation, safeguarding your battery’s lifespan and protecting against unexpected voltage spikes. This innovative circuit, featuring a 10-second delay, ensures safe overnight charging and prevents damage from power outages, extending your battery’s life and providing peace of mind.... [read more]

Build a powerful 7815 battery charger capable of delivering up to 4.4A, expertly tapering to 0A at 15.0V. Maximize your battery charging efficiency with this design, featuring a 7815 regulator and a robust current limiting circuit for optimal performance and reliability.... [read more]

Safeguard your valuable battery investments and unlock limitless possibilities with this innovative micropower battery protector. This compact switch, rated up to 10A, seamlessly protects batteries from over-discharge, ideal for 4.8V to 12.5V systems, including 6V and 12V lead-acid batteries and 4-10 cell NiCd/NiMH packs. Build your next groundbreaking project today!... [read more]

Build a smart battery status indicator circuit for portable test equipment, operating from 5V to 12V. This innovative design uses a flashing LED to alert you to low battery levels, ensuring your instruments never unexpectedly shut down.... [read more]

Build a smart battery saver circuit with a delay, automatically turning off your device when the ambient light is low – perfect for conserving power and ensuring your display is always readable. This innovative design utilizes a MOSFET and LDR sensor for efficient power management, ideal for devices running on 6 or 9V batteries and drawing up to 100mA.... [read more]

Predict impending battery failures in your 24V power system with this innovative LED circuit. This simple schematic utilizes a voltage difference detection to alert you to failing batteries, ensuring your truck, 4WD, RV, or boat remains powered. Build this essential monitoring system today.... [read more]

Protect your 12V fridge and car stereo systems with this vital circuit, designed to prevent battery drain and ensure reliable operation. This innovative Battery Guardian automatically cuts power when voltage drops, safeguarding your investment and avoiding costly breakdowns. Build your own system and enjoy peace of mind.... [read more]

Build a reliable battery charger detection circuit with this easy-to-implement schematic. Safely monitor your power supply’s output with a 3 to 15V range and 1A maximum current, ensuring your devices receive the optimal charge.... [read more]

Build powerful charging circuits with precision! Design efficient battery charging systems using voltage dividers and constant current sources for optimal power delivery and extended battery life.... [read more]

Design a powerful lithium battery charger to fuel your projects with this innovative circuit. This meticulously crafted charger precisely manages the charging of series lithium cells (3.6V, 1Ah) ideal for portable electronics. Optimize charging performance by adjusting the current and monitor charging status via an LED indicator. Unleash your ingenuity and build a reliable charging solution today.... [read more]

Build a vibrant 4-LED voltage bar graph to precisely monitor your 3.6V lithium-ion battery’s performance. This circuit, utilizing a TL431 reference and a meticulously designed voltage divider, displays voltage levels from 2.46V to 3.9V, empowering you to optimize battery usage and achieve peak performance.... [read more]

Unleash the Power Within: Build Your Intelligent 12V/6V Battery Charger Transform your automotive projects with this expertly designed charger! Featuring a powerful 6.8V/15V output and precise 1.2A regulation, you can confidently build a robust, fast, and reliable battery charger. This circuit, with its innovative use of a 230VAC transformer and clever component selection, provides the ideal foundation for your advanced projects. Optimize your build with the trimmer pot (TR1) and gain the confidence to tackle complex battery charging challenges. Let's build something extraordinary!... [read more]

Build your own precise battery tester and unlock the secrets of voltage measurement with this innovative circuit. Discover how to create a reliable system for testing batteries with a constant current load, ensuring accurate results and saving you money.... [read more]

Quickly test batteries from 1.5V to 15V with this innovative circuit, revealing battery health and ensuring optimal performance – build your testing solution today!... [read more]

Build a robust and reliable 4-stage power supply unit for your electronic circuit testing – providing precise 12V, 9V, 6V, 5V and 18V outputs to safeguard your valuable components and ensure accurate results.... [read more]

Design a robust and versatile DC power supply capable of delivering up to 3A, ideal for prototyping and powering your electronic projects. This adjustable power supply offers a stable 3 to 30V output, perfect for experiments and builds.... [read more]

Build a robust and reliable power supply with this simple yet powerful circuit. The 7809 regulator delivers up to 2 amps, ensuring a clean and stable 5V output. Includes reverse polarity protection with a 1N5400 diode and optimized filtering for logic circuits with a 100nF capacitor.... [read more]

Build your own versatile adjustable power supply, generating precisely controlled voltages from 1.3V to 22V with up to 1A of current. This compact, easy-to-assemble circuit, featuring an LM317T regulator, unlocks limitless design possibilities.... [read more]

Build a versatile current-limited power supply with adjustable outputs from ±5V to ±15V, using an LM317 and LM337 for precise current control and stable regulated outputs.... [read more]