We may earn commission from links on this page, but we only recommend products we love. Promise. Keep scrolling for the full list of the best at-home red-light therapy devices below, along with ...

If you’ve worked on a project with small LEDs, you know the frustration of determining their polarity. This ingenious LED Probe from [David] packs a lot of useful features into a simple, ...

This circuit can be used to test up to three LEDs at once, connected in series. You can easily increase that number by using a higher supply voltage. If you do so, you should allow 2.7 V for each ...

[mircemk] built a slick-looking LED tester with a couple handy functions built in. Not only can one select a target current to put through an LED, but by providing a target voltage, the system will ...

We independently review everything we recommend. When you buy through our links, we may earn a commission. Learn more› By Thom Dunn Thom Dunn is a writer focusing on home heating and cooling. He once ...