The polarity markings on LEDs (Light Emitting Diodes) seem to be a common cause of confusion. The polarity may be indicated by a flat section on one side of the body or by one lead being shorter than ...

What do you get for the geek who has everything and likes LEDs? A tricked-out LED tester, naturally. [Dave Cook]’s deluxe model sports an LCD screen and two adjustable values: desired current and ...

Some diode manufacturers caution against using the diode tester function in ohmmeters because it could exceed the reverse-voltage and forward-current ratings of sensitive diodes. This is especially ...

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 ...

The circuit has been constructed to provide an in-circuit system that will test the integrity of electronic components such as Silicon Controlled Rectifiers, diodes, and PNP or NPN transistors. 4093 – ...

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, ...