14 may 2015

Next step in the LISN filters

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Honkin' 5 uH, 50A inductorsI´m getting closer to having my CISPR25-spec LISN – used for automotive and other DC-input circuits. Below are some photos of the 5 uH, 50A inductors built for me by a local magnetics company. They´re not pretty, but they´re both pretty close to 5 uH. That´s 4mm diameter, solid copper magnet wire, by the way, and I just about broke my hand trying to cut it! Fortunately the bass player from my band is an electrician and he lent me the heavy duty wire cutters in the photo!
The old laptop I was using to run my AP300 netowkr analyzer/LCR meter finally died. The hard drive motor kept making these awful, wheezing, groaning sounds, and finally three days ago it stopped – for good. Fortunately the desktop I´m planning to use as my arcade machine is on the same bench, so for now it´s doing double duty. Below are the scans of inductance and resistance for both devices. My big debate now is whether to add more capacitance to the filter for the lower inductance device. What I plan to do is have a lot of footprints for the capacitor bank, since it´s made up of multiple film caps, so that I can adjust as needed to get the final impedance set by CISPR25.

LISN 5uH #2 L and R LISN 5uH #1 L and R

26 abr 2015

Arcade Machine: Getting Started!

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LTC6995-1 Turbofire CktI´m building my own video arcade machine with the help of a friend who´s an architect and an AutoCAD master. I´ll post photos as it develops – today I looked at samples of different woods and picked natural birch. The finish of the machine will be natural wood – I want it to look like a piece of fine, solid-wood furniture. It´s going to be very heavy, but very elegant.
Most of the hardware is purchased, but I did custom design a series of astable multivibrators using the LTC6995-1. A toggle switch selects between normal, one-press-one-cycle button pressing and turbofire. I set it to 20 Hz and that seems to work quite well. This is for all those shooting games, from Galaga to the present where you´d end up with a severe case of Carpel-Tunnel syndrome if it wasn´t for turbofire!

20 abr 2015

Blue laser pointer

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This is my first post after a series of hacks killed my website, I´m still not sure if it was twice or three times.
In any case, the local OSRAM-OS salesman graciosly samples me five PL-450B laser diodes, which are a stunning, beautiful royal blue at 450 nm. I ordered some housings from Taiwan because the TO-38 package is tiny, and has a weird shape. I´ve designed a very nice two-stage LED driver using the LTC3537, which is a synchronous boost converter and LDO in the same IC. This runs from a single 18650 LiON cell. (One cell caught on fire while I was «harvesting» them from a dying laptop battery. They ARE twitchy!) The driver provides a very clean, constant 100 mA.
What´s holding me back on this project is the mechanical side. I want an aluminum tube to hold the battery and the LD housings, and then a momentary contact switch right in the middle of the tube where it´s easy to press with a thumb as you point towards a screen. Directly opposite I want a MicroB USB jack, because I want to be able to recharge the LiON cell without removing it from the laser pointer. So far my attempts to find a manufacturer of custom designs in aluminum have failed. Eelectronics are easy compared to mechanics!

05 sep 2013

New service added / Nuevo servicio añadido

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I´ve just added a new page to the web with details on my newsest service: opening up and testing pre-manufactured or «catalog» power supplies. Check out the link for details!

Power Supply Testing

Acabo de añadir un enlace nuevo para un servicio nuevo: abrir y probar las fuentes de alimentación pre-fabricadas, o «de catálogo». Muy pronto pondré la pagina en español también. De momento los detalles están en inglés por en enlace arriba.

05 sep 2013

Back to work! ¡De vuelta al trabajo!

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Hello All,
I had an excellent time with Converter Technology, working on fairly standard flyback, and LED driver, and having the most with with an LLC half bridge converter. Iain and Anthony were great, and so was the tea. Now it´s nose to the grindstone.

Hola a Todos,
He pasado un mes increible con Converter Technology, probando un flyback, un driver de LEDs y, sin uda la más divertida, una fuente half bridge LLC. Ahora me pongo a trabajar aquí.

Hello All! I´m pleased and excited to announce that I´ll be spending the entire month of July in Reading, England, working with my friend and former NSC colleague Dr. Iain Mosely. Iain´s company, Converter Technology, also speciaizes in power management, and I´m looking forward to working with some high voltage, high power supplies, and learning how to do so without electrocuting myself!

Hola a Todos! Anuncio con muchas ganas que pasaré el mes de Julio en Reading, Inglaterra, trabajando con un buen amigo y ex-compañero de NSC, el Dr. Iain Mosely. Su empresa, Converter Technology, también se especializa en gestión de potencia. Espero trabajar con unas fuentes de altas tensiones y altas potencias, y aprender a probarlas sin electrocutarme!

Hello All,

Things are moving quickly – new computer, Altium up and running, the ESD lab benches are all set up and lab equipment is coming in faster than I can set it up! I´m all fired up!

 

Hola a Todos,

Las cosas ya van rapidamente – nuevo portatil, tengo Altium funcionando, los bancos ESD están instalados y el equipo de laboratorio llega tan rapidamente que ni siquiera tengo tiempo de montarlo todo. ¡Estoy genial!

Chris