I’ve been lucky enough recently to score a Keithley 2304 power supply off ebay for a measly $75. For those unfamiliar, these are high speed battery simulator units capable of measuring very low currents and also behaving like a battery and sinking current.
Original ebay picture
It’s been a while since we’ve fixed anything. But no worries- something always breaks around here! Lately, our fancy electrical dryer decided to call it quits. Continue reading
Here is another silly hack I’ve finally got around to do and document. We have a BioBrite SunRise alarm clock at home that nicely simulates sunset and sunrise.The clock is almost perfect with one notable exception- backlight is exceptionally bright even when it dims it for the night mode. This post describes how I fixed that. Continue reading
Today we have a repair that’s somewhat off-topic for the typical posts here. But hey, it broke, got fixed- might as well document for others. Plus it has some wires inside- that counts!
Today we have two tiny multimeters to take apart and see what we can learn from how their designs progressed:
On the left is Hioki 3217 and on the right – Beckman DM78
I stumbled on these lights at the local Home Depot store this weekend, and was intrigues by the price ($9.95 despite being listed at $20 online) and also the versatility. You can simply screw one into an exposed lamp holder and end up with a fixture instead of a bare bulb, while also using a lot less energy.Or you can use a supplied socket with a pigtail and wire it to a ceiling box. In my case, I was looking to improve garage lighting. A single 60W bulb was just not cutting it and I am not a big user of fluorescents. These things being small and light but also enclosed would be a good choice there
Retail box front
Another addition to my growing collection of vintage multimeters is this Weston Schlumberger Model 6000 meter from the mid 1970s
Old vs new(ish)- notice how square it is
The meter was listed as in almost like new condition except for a spot on the front panel. It came with (very rubbery) test leads and an actual printed user manual- a rare thing these days.The Ebay posting was worded very carefully to never mention whether the thing actually works, so I figured it did not really matter. If it does not- teardown turns into repair attempt and either way we learn something new. Continue reading
The latest addition to our vintage collection is a Keithley 130A handheld DMM from the mid-eighties.Keithley is not well known for its handheld DMMs, or at least I’ve never heard of them. It’s a 3.5 digit 0.25% instrument made in mid 1980s
The thing is tiny! Shown next to the EEVblog uRuler
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
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.
Schick Hydro 5