Dolabra put together this 5 volt solar power supply. The solar panel recharges a single alkaline battery which is then boosted to 5volts via an NCP1402 breakout board. Maximum output is 200 mA. I broke all the rules — I soldered directly to the battery and I’m recharging an alkaline. I’m surely going to be […]
Category Archives: power supply
Offline high voltage AC power supply
Dilshan designed an offline high voltage AC power supply primarily for SMPS testing. It outputs a square wave, so hooking it up to a mains-transformer based linear supplies is not a good idea, as the transformer will overheat. It’s open source hardware, so the schematics and design files are available. This is a high voltage, […]
ATX breakout board bench power supply back in stock
The ATX breakout board bench power supply is back in stock at Seeed Studio. This board recycles an old computer PSU into a handy bench tool with 3.3/5/12/-12 volt supplies. You can get one for $14 at Seeed Studio.
Benchtop power supply based on ATX Breakout board
Software & Sawdust posted his new Benchtop power supply based on the ATX Breakout board. It features our breakout board, and an ATX power supply packed together into a custom wood case. This is a project that’s been in the back of my mind for a long time but I just never seemed to find […]
App Note: Adjustable power supply using a digital potentiometer
How to use a digital potentiometer to calibrate and control an adjustable power supply. A resistive feedback network is often used to set the output voltage of a power supply, since fixed resistors are simple to use and low cost. However, because a fixed network is not adjustable, the output voltage cannot be accurately set. […]
Scalable 12V solar power system and battery charge controller
Squonk writes about this scalable solar charger he’s located: An unconventional, scalable high efficiency 12V solar power system and battery charge controller with low voltage cutout to protect the battery. (ideal for systems of 50W or less). The most common solar charger consists of a Schottky diode to prevent the battery from draining into the […]
The impact of high pulse drain on CR2032 coin-cell battery capacity
If you design circuits powered by CR2032 batteries here’s an article located by Joe Desbonnet which you should consider: This is an interesting article on how the performance of a cell/battery under pulsed loads can vary dramatically depending on period, peak current, duty cycle and other factors. The article discusses the performance of a CR2032 […]
New 7400 Competition sponsor: Tautic Electronics
Tautic Electronics has donated five dual output breadboard power supply to the Open 7400 Competition. Get your entry in and this and other cool hardware can be yours.
Another OverLoad review
Another review of ITead’s OverLoad programmable dummy load: All in all, interesting device. The only major flaw I see attm is that instead of using DAC and drive the current value trough mcu they are doing that analogue … I’ll check schematic to see if there is DAC on board at all, but if not […]
Designing and building a bench supply
Another article that might help with bench power supply designs: A good, reliable and easy to use bench power supply unit is probably the most important and most used device in every electronic lab. A proper electronically stabilized bench power supply unit can easily cost over 200 Euro. Using a clever microcontroller based design we […]
Unboxing the OverLoad programmable dummy load
tempmj posted his first impressions ITead’s new programmable dummy load. Via the forum.
FSAR001 AC to 5volt DC regulator
schazamp built an FSAR001 experimenter board: This device, remember, takes 80-265Vrms wall power and puts out a (relatively) clean 5V DC. According to the datasheet, the way this thing works is by monitoring the voltage of the AC waveform and charging a big electrolytic capacitor during the low voltage segments on the leading and trailing […]
True RMS explaned
Not everyone understands how multimeters measure RMS voltage. Doug Criner has put a good explanation. Can there be more than one RMS value of a voltage waveform, but only one of them is true? Apparently so.To use simple Ohm’s law and power calculations for a periodic waveform, we must know its RMS, or root-mean-square value–which […]
Digitally controlled power supply
Here’s a design for a digitally controlled power supply: I’ve built quite a few power supplies over the years; it’s an almost vital tool for electronics. It’s been my plan to built one which would drop the analog potentiometers in exchange for digital control with a microcontroller. There are many advantages to it as well […]
1.5 to 10 volt inverter
If you need a 5 to 10 volt DC power source and only have a couple AA batteries, here’s a simple solution from CoolCircuits. It uses four transistors and a handful of passive components to produce an adjustable 5 to 10 volt output from 1.5 to 4.5 volt input.
Switched-mode power supply design
Clearing out old posts before the new year, some of these might seem ancient. Great read on switch mode power supplies. From the comments: Maybe you want the index page, or the SMPS page. From the contact form, via Adafruit.
Boost driver for long LED strings
rsdio tipped us to an app note on a Boost driver for long LED strings. The long strings of LEDs commonly found in TV and display backlighting, street lights, and parking garage lights require a current driver capable of producing high voltages. This reference design provides such a driver using the MAX16834, and demonstrates how […]
Simple current limiter is programmable
rsdio tipped us to an app note on a simple current limiter. This circuit lets you program a current limit without using microcontrollers or data converters. It consists of a charge-pump voltage doubler (U1), a current-sense amplifier (U2), and two n-channel MOSFETs. The sense-resistor value determines the maximum current limit. Thanks rsdio!
Building a DC-DC power supply that works
rsdio tipped us to an app note on DC-DC power supplies: This article discusses important considerations when designing a DC-DC power supply. Topics include choosing the right DC-DC converter for the application; MOSFET gate capacitance; high switching frequencies and component size; equations and calculations; selecting peripheral components; component placement and trade-offs; grounding; load and line […]
PIC programmable power supply
We’ve been working on a new power supply in the forum, so this programmable power supply project was an interesting read. The PIC adjusts the output voltage using input from a keypad. Via Hack a Day.