madbeanpedals::forum

General => Open Discussion => Topic started by: AntKnee on April 03, 2017, 06:09:44 PM

Title: Mastech Multimeter - Does yours measure forward voltage?
Post by: AntKnee on April 03, 2017, 06:09:44 PM
My Mastech meter lights up the LED, but gives no reading on the voltage. It always reads "OL".
It may not work on this function, or it my be a crappy meter. If anyone could try with their Mastech Meter and post up, I'd appreciate it.

Please only post regarding the Mastech Meters, that is all that will help me. Thank you!
Title: Re: Mastech Multimeter - Does yours measure forward voltage?
Post by: thesmokingman on April 04, 2017, 12:01:38 AM
OL has two meanings when measuring diodes, reverse biased (but LEDs light when forward biased) or over limit(this is usually the case). I believe a good deal of multimeters will measure up to 1V Vf and LEDs are higher than that.
Title: Re: Mastech Multimeter - Does yours measure forward voltage?
Post by: culturejam on April 04, 2017, 12:59:26 AM
OL is probably "over limit". For water-clear LED, sometimes they have a forward voltage greater than what the meter can deliver at the current needed to turn the LED on (for long enough to measure). 

Try a diffused LED and see if it works normally. If so, that's probably the issue. I had a meter that wouldn't measure anything over 1.2V, so some water-clear would work, and others wouldn't.