Pre-spun hard drives

spinmaster

This device is lovingly called the SPINmaster. [Linux-works] built it to spin up multiple hard drives before the motherboard starts up. It detects the power-up from the PSU and uses a relay to hold the motherboard in reset, indicated by the red LED. Each of four relays then spins up a hard drive and illuminates the green LED when ready. Once all green lights come on the reset relay shuts off and … [Read more...]

Dual voltage power supply

dual_regualted_power

[Melanie] had some time this weekend so she whipped up a dual voltage power supply from parts on hand. This design plugs right into a breadboard and, unlike the last breadboard power supply we saw, provides two voltages at one time. 5v is delivered to one power bus while 3.3v goes to the other. Her design uses two linear low voltage drop regulators from the LF00 family (PDF datasheet) to … [Read more...]

Tube amplifier in a PSU

tube_amp_in_psu

[Niclas] sent us his home made tube amplifier. For the case he used a computer power supply unit, took out the guts and replaced them with the amplifier board. He based this build off of an existing design but took a more minimalist approach. The wooden face plate has an on/off switch, an audio jack, and volume control. Apparently, the tubes are floating loose inside of the case. We'd recommend a … [Read more...]

Regulated breadboard PSU

sparkfun_bbpsu

SparkFun has released a breadboard power suppy that can provide regulated 3.3v or 5v. Unlike the supply we saw from adafruit industries earlier this summer, this one is based on an lm317. This small device features on/off switch, voltage selection swith, and appropriately spaced pin headers to plug into both the top and bottom rails of a standard breadboard.  Rather build it yourself? Take a look … [Read more...]

Bench power supply adapter

psu_adapter

Every electronics workbench could benefit from having a bench power supply. Converting a PC power supply works, but often, it involves splicing wires and limits the supply to only bench use, and building one from scratch is definitely an undertaking. To counter this, [silic0re] and his father came up with a detachable adapter that simply plugs into the existing connectors. The adapter provides … [Read more...]

Compaq motherboard power mod

cpq2atx_brd2

Some companies insist on using proprietary pieces. It can be really frustrating when there is no apparent reason other than consumer lock in. It irritates us to feel like we're being forced to buy their pieces. This is one of the more popular reasons listed when you ask a hacker or modder what got them started.  This project takes us through making a normal power supply work with the compaq … [Read more...]