Supercapacitor uninterruptable power supply (UPS) for Raspberry Pi

smbakeryt built a couple supercapacitor uninterruptible power supply (UPS) prototypes for his raspberry pi projects: For my Convergent restoration, I decided to build an RASCSI to replace some failing SCSI hard drives. The RASCSI is a SCSI emulator built using a raspberry pi. Problem with these types of emulators is that if you carelessly power […]

Convert an ATX computer supply to a bench power supply

Using an old computer ATX power supply as a high-performance workbench power supply @ DroneBot Workshop: A Bench Power Supply is an essential component for any serious electronics experimenter. But a good supply with multiple output voltages and a high current capability can set you back some serious cash. In this article we’ll look at […]

A different power source for field ham radio operating

Gwen, NG3P, has been working on a power source project for field ham radio operating: We’re coming up on a confluence of two things: Nice weather, and relaxing of the Covid-19 lockdowns in much of the United States. This means more hams leaving their home shacks and taking their operating to the field. For some, […]

Tiny transformer inside: Decapping an isolated power transfer chip

Ken Shirriff writes: I saw an ad for a tiny chip1 that provides 5 volts2 of isolated power: You feed 5 volts in one side, and get 5 volts out the other side. What makes this remarkable is that the two sides can have up to 5000 volts between them. This chip contains a DC-DC […]

DIY long lasting voltage regulator circuit for Raspberry Pi

Jithin @ rootsaid.com writes: Raspberry Pi is simple, handy and cheap yet powerful single board computers of all time. It has USB ports to connect hardware such as pen drive, keyboard, mouse, HDMI port for display out, 3.5 mm port for audio and several GPIO pins to work with embedded projects, all of which can […]

Building an extremely high powered 1-12V lab power supply on the cheap

Matthew Millman has published a new build: For a number of years now I’ve had a couple of high powered switching power supply units made by Power-One. They’re typically found in I.T. equipment and provide a single output rail of either 12 V or 48 V with a very high current rating. The other cool […]

Building a Power-over-Ethernet (PoE) power supply using a DPS5005 module

Dr. Scott M. Baker has designed and built a PoE-powered lab power supply using a DPS5005 and custom PoE board: The DPS5005 is a DC-DC converter. It can accept an input voltage from 0 to about 55 volts or so, and will regulate an output voltage up to about 1 volt below the input. This […]

Teardown of an Amrel PPS 35-2 programmable power supply

Kerry D. Wong did teardown on a single-channel Amrel PPS 35-2 programmable power supply: A while back, I did a teardown on a dual-channel Amrel PPS-2322 programmable power supply, and was quite impressed by its solid construction. Recently, I found another Amrel power supply on eBay and this time it is a single channel version […]

Understanding and repairing the power supply from a 1969 analog computer

Ken Shirriff writes: We recently started restoring a vintage1 analog computer. Unlike a digital computer that represents numbers with discrete binary values, an analog computer performs computations using physical, continuously changeable values such as voltages. Since the accuracy of the results depends on the accuracy of these voltages, a precision power supply is critical in […]

Teardown and modification of an Electrophoresis power supply

Kerry Wong did a teardown of an EC600-90 electrophoresis high voltage power supply: Electrophoresis power supplies are commonly found in biology and other life sciences laboratories. These power supplies are usually capable of supplying high voltages and high currents required for gel electrophoresis–a method used for separating DNA, RNA and other protein fragments based on […]

Teardown and repair of an GW Instek PSW80-40.5 1080W multi-range programmable power supply

Teardown and repair of an GW Instek 1080W power supply from The Signal Path: In this episode Shahriar investigates the failure of a GW Instek 1080W power supply capable of providing up to 80V and 40A of programmable output voltage and current respectively. The power supply does not power on. However, relay noises can be […]

Inside a two-quadrant power supply – Agilent 66312A teardown and experiment

Kerry Wong did a teardown of an Agilent 66312A dynamic measurement DC source: Typically, a lab power supply can only operate within a single quadrant. Take a positive voltage power supply for example, it can only output or source current. If any attempt is made trying to sink current into the power supply by connecting […]

Glowing mercury thyratrons: Inside a 1940s Teletype switching power supply

Ken Shirriff take a look inside a bulky DC power supply REC-30 rectifier, how it works and contrast it with a MacBook power supply: We recently started restoring a Teletype Model 19, a Navy communication system introduced in the 1940s.14 This Teletype was powered by a bulky DC power supply called the “REC-30 rectifier”. The […]

DC/DC switcher for 5v TO 3v at 750mA in a TO-220 7805 footprint

An open source small DC/DC 3W switcher to drop 5V to 3V in a 7805 TO-220 pinout from Black Mesa Labs: This post is an open source hardware design from Black Mesa Labs for a simple DC/DC converter for dropping 5V to 3.3V ( or adjustable to lower voltages via resistor selections ). The design […]