Tap On! Tap Off! The Backlight!

We recently covered [TechnologyCatalyst’s] excellent $50 multimeter shoot out, and we weren’t surprised when the winner was the Uni-T UT61E. It’s jam packed with features, and has a lot of bang for your buck. But one thing that it’s missing is a backlight.

The 61E uses a chip form CyrusTek called the ES51922A. This chip has a back light features built into it, but Uni-T simply didn’t add the supporting circuitry and LEDs. This was done either to keep cost down, or to not take away sales from their higher end models – your guess is as good as ours. Even though several people have tried carefully soldering to this fine pitch chip package to add back lights, the backlight timer is set to turn off in 60 seconds.

[Nisei] on the EEVBlog forum came up with an elegant capacitive touch solution that we could see being used in many other applications. The mod centers around a using a TTP223 touch sensor module that you can find on eBay for $1 instead of tapping into the meter’s dormant backlight controller. Add in a voltage regulator, a resistor, 2 leds and some foil tape, and that’s about all you need. [Nisei] did a great job documenting the mod with graphics rather than pictures (that can be a bit ambiguous at times.) Also, in case you missed the $50 DMM review you can find it here.

With all that said, we’re thinking the next multimeter mod might just need to be the “Clap-On, Clap-off” meter.