Please help identify this component - Page 1
Forum section: electronics / beginners

author: tigerstyle
author_rank: Contributor
timestamp: December 23, 2015, 12:01:46 pm
content: It's on a PWM board, I believe it is a diode? to stop the current flowing the wrong way between the input through the 3 way toggle switch to the output?On the board I have here it blew, I think it was because the guy using it didn't cut the copper tails short enough on the leads he was connecting, so it went through the back of the terminal block and contacted the diode leg directly.I'm not sure if it is a diode though, but would like to replace it and get the board (maybe!) working again, they are only cheap but want to play over christmas when I can't get one delivered!It was a pretty big one on there, but not sure

author: alsetalokin4017
author_rank: Super Contributor
timestamp: December 23, 2015, 12:08:43 pm
content: Yes, it looks like a diode, probably something like a 6 amp fast rectifier. How do you know it blew?Perhaps FR610 ?http://www.citcorp.com.tw/pdf/F-Fast%20Recovery%20Rectifiers/DS-11F10_REV_C1_FR6005%20SERIES%28R-6%29.pdf

author: tigerstyle
author_rank: Contributor
timestamp: December 23, 2015, 12:11:13 pm
content: It left the board in pieces! ...The magic smoke came outWould this be a good replacement?http://www.maplin.co.uk/p/p600d-6a-silicon-rectifier-uk60q

author: alsetalokin4017
author_rank: Super Contributor
timestamp: December 23, 2015, 12:17:12 pm
content: Quote from: tigerstyle on December 23, 2015, 12:11:13 pmThat's a pretty good indication that it's blown! I don't suppose you can read the part number any more...QuoteI'd try the FR610 in preference. It is faster and higher peak voltage handling. Also very commonly available.

author: Richard Crowley
author_rank: Super Contributor
timestamp: December 23, 2015, 12:31:55 pm
content: Remember that is a high-frequency switch-mode power supply (SMPS) circuit which requires a fast recovery time diode. Conventional mains-frequency diodes are not suitable for that circuit.Note also those SMPS circuits are a house of cards. When one component goes, it frequently takes out several others around it, particularly semiconductors. There is a good possibility that other transistors and/or integrated circuits are blown as well. Most boards like that are undocumented and use mystery "house-number" (or no-number) parts and are so inexpensive, they are hardly worth component-level diagnosis and repair.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: December 23, 2015, 12:36:33 pm
content: Quote from: blueskull on December 23, 2015, 12:21:27 pm300V, 12A. It would probably work, depending on the load inductance. The package on the board is larger than the 5400 series, looks more like a higher-voltage, lower current rating diode to me.Although it could be a 6A10, which is a big fat diode like that but only 100 V.Here's a photo comparing a 1n5400 with a 6A100 (6A, 1kV), if that helps:

author: alsetalokin4017
author_rank: Super Contributor
timestamp: December 23, 2015, 12:38:49 pm
content: Quote from: Richard Crowley on December 23, 2015, 12:31:55 pmAgreed. The diode should be a fast recovery type and high voltage handling. I would also suspect that the mosfet has probably failed too.

author: IconicPCB
author_rank: Super Contributor
timestamp: December 23, 2015, 12:48:21 pm
content: If it were a switcher we ought to e ale to identify the inductor.It is a DC motor driver most probably ( hint see CW and CCW on component legend layer.

author: tigerstyle
author_rank: Contributor
timestamp: December 23, 2015, 12:52:04 pm
content: http://www.maplin.co.uk/p/p600j-6a-silicon-rectifier-uk61rThat has a higher voltage peak than the previous one I linked too, I'll buy it and test it, not a big loss either way.I can see that yes, if this blew big style, then other parts of the board will have taken damageThanks all for the help!

author: alsetalokin4017
author_rank: Super Contributor
timestamp: December 23, 2015, 12:55:40 pm
content: Quote from: blueskull on December 23, 2015, 12:44:18 pmMaybe. I was thinking it was there to protect the mosfet from inductive spikes from the motor. Why else use a big fat diode like that, if you are just protecting from reversed input voltage?

author: alsetalokin4017
author_rank: Super Contributor
timestamp: December 23, 2015, 01:01:30 pm
content: Quote from: tigerstyle on December 23, 2015, 12:52:04 pmCan you post a photo of the backside of the PCB? I'd like to see how the diode is connected to the rest of the circuit. If it's for protection from inductive spikes, you might indeed need a fast recovery diode.

author: wblock
author_rank: Regular Contributor
timestamp: December 23, 2015, 06:33:28 pm
content: Quote from: alsetalokin4017 on December 23, 2015, 12:36:33 pmThat appears to be correct. Searching for pictures of that board ("6-30V DC Motor Speed Controller Reversible PWM") finds some with the 6A10 diode. Some with others, too.

author: tigerstyle
author_rank: Contributor
timestamp: December 23, 2015, 09:20:52 pm
content: Oh fantastic, so the diode I can buy off the shelf here is rated to 600V not 1000VWe'll give it a try!Otherwise the rest of the board is probably blown anyway so no big loss!Thanks again all!Learning everyday!

author: tigerstyle
author_rank: Contributor
timestamp: January 01, 2016, 11:25:45 am
content: It worked! What a successSoldered in the diode, took care of the wiring to keep it neat and no more shorting out, awesome stuff!