How to test a bridge rectifier with a multi-meter

you hey what's happening guys I am finally feeling better so we're gonna be getting back into some cool projects here pretty soon here's a sneak peek at one a few more of that later anyway today we're gonna do is I'm going to show you how to test a bridge rectifier to make sure it's functioning properly using nothing but a multimeter this is just a standard bridge rectifier here and it's kind of hard to make it out there you can see we have plus AC AC and minus so the first thing you need to know to do this is you know what is a bridge rectifier I'm sure most of you guys already know but if you don't it's basically for diodes like this and this is our plus all look at that beautiful red marker this is the minus and then these two here are our a C's in so this goes over to AC usually to a transformer something like that and then this comes out here so positive that goes to our load then it comes back into the negative so that's basically how a bridge rectifier works for diets if you ever wondering how to draw them just remember all the diodes point towards positive real simple remember remember beautiful so to test a bridge rectifier to find out if it's working all you really need is a multimeter so we'll bring out the fluke here Oh simple put it in diode mode now here's a standard diet it's like a one in four thousand seven I think there's the anode there's the cathode we clip it up like that and you see we get a voltage drop of about a half a volt it could be as low as point four it could be as high as point seven somewhere in this range that's a good voltage drop for your basic silicon Junction diode now if on the other chance you have Schottky diodes well then you're gonna see something different the voltage drop is going to be much lower and Schottky diodes and silicon Junction diodes look exactly alike so you have to tell by the part numbers anyway so reason I showed you that so you know what the diode drop looks like so to test what we're gonna do here this is remember this is starting from the left positive AC AC negative we're going to put our positive lead on the negative and then we're going to put our negative lead on the AC and you see we have a standard diode drop reverse them and we should have absolutely nothing just like that next we're going to put our positive on the other AC and our negative on the positive and we have another voltage drop or another diode drop if we reverse them we get nothing and this might be particularly to this bridge rectifier but if you connect the positive to the negative in the right direction here you have nothing but if you reverse it you get about a 1 volt so you get a double diode drop okay so as long as you're getting those two diode drops everything is copasetic all right let me show you here on the diagram just so you were clear so step one is you're going to connect your your meter positive to the negative on the rectifier alright then you're going to connect meter negative to the AC it's closest to the rectifier and then you should get your drop then if you reverse that you should get nothing open-loop and step three is you put your meter negative on the positive for the rectifier and your meter positive on the AC and you should get a drop step four reverse that and you should get nothing step 5 meter positive to negative on the rectifier and meter negative to positive on the rectifier you should get your drop squared or actually not squared it's drop times to a double diode drop all right so that is a super easy way to test whether or not your bridge rectifier is working or not using nothing more complicated than a multimeter hope you guys enjoyed this if you did give me a thumbs up feel free to comment share and don't forget to subscribe big thanks to all the patrons big thanks to everybody who supports the channel in any way especially the guys who sent me uh some PayPal donations recently thank you very much alright that's it I'm out peace hey thanks for watching the video guys I really appreciate it I appreciate the support of everybody who donates via patreon or PayPal and another way to help out the channel is to buy things from the Amazon store there's a link down below it doesn't cost you anything and I make a few pennies we have some fun here so please feel free to comment on any video your comments are always welcome and you can email me at Arduino zero one six nine at gmail.com

Channel: learnelectronics

Views: 73,366

Rating: 4.8987875 out of 5

Keywords: How to test a bridge rectifier with a multi-meter, full bridge rectifier, diode, diode drop, ac-dc

Id: K-oNaQvMQco

Length: 7min 55sec (475 seconds)

Published: Thu Jan 16 2020