New toy- Yokogawa CL 220 clamp meter

Posted on November 29, 2013 by reagle

The thing is tiny! Shown next to the EEVblog uRuller

The thing is tiny! Shown next to the EEVblog uRuler

Introduction

I’ve been looking for a good clamp meter for a while now. While there is plenty of no-name cheap meters on Ebay, I figured I’d wait till something better “washes ashore”. So when a Yokogawa meter got caught in my ebay filters one day, I grabbed it. Yokogawa is a Japanese company, well known for their power measurement equipment. This meter has a nice mix of AC and DC current ranges fitting my low to medium current measurements needs. It is also a recent model, still being made and supported- a rarity in my lab setup of 20+ year old equipment Continue reading →

Schick Hydro 5 razor teardown

Posted on November 9, 2013 by reagle

Today’s teardown subject has been waiting for its turn for a while- I picked it up at the last Design East conference in Boston in 2012. There, Microchip and Energizer were talking about low power design and using these Schick Hydro 5 power razors as an example. Hot on the heels of my repair of a Philips Sonicare toothbrush, this seems to be a good fit for a comparison. Both things do essentially the same thing- they shake, light up some LEDs and not much else.

Product unpacking

Schick Hydro 5

Continue reading →

Part of the week: LT8554 and on the art of cell balancing

Posted on November 8, 2013 by reagle

This week’s part of the week is a Linear Technology’s LT8584. The part is a DC-DC converter that is designed for a very specific purpose- active balancing of battery cells. In a typical long battery string, no matter how tightly matched initially, there will always be cells that end up with a bit more or a bit less charge. Over time these imbalances start affecting what the battery can deliver, as one week cell may trigger undervoltage limit for example and shut the whole pack down despite other cells being perfectly happy. Continue reading →

Philips Sonicare HX6710 teardown and repair

Posted on November 3, 2013 by reagle

Today we have a new subject to tear down- my own Sonicare toothbrush. At the end of a brushing cycle it made a short “Beep” noise and went silent. No reaction to button press or to putting it on a charger. No lights, sounds or anything. Oh well, might as well take it apart.

Philips Sonicare