Help identifying NPN or PNP in repair, also looking for that EE video course. - Page 1
Forum section: electronics / beginners

author: XOIIO
author_rank: Super Contributor
timestamp: September 24, 2015, 03:11:38 am
content: Well, someone has a blender which one day "just stopped working", and I figured it may be a motor, or a fuse, something like that, the thing was packed full of flour, however when I pulled the board out, I think I found the issue lol. This transistor has had the absolute ass blown out of it.Unfortunately I haven't messed around with transistors enough, so my question in case someone can instantly identify the type, is if it's a PNP or NPN transistor, but more so, how you go about identifying it in this case, since I could just pop in one of each and see what works. I've always liked the idea of reverse engineering circuits to find unknown/specialized components, or in this case, ones that are just blown apart.Also, there were a bunch of free EE lectures online that I never got around to watching, does anyone have a link to those?

author: IconicPCB
author_rank: Super Contributor
timestamp: September 24, 2015, 03:39:49 am
content: and then again .. it might be an scr or a triac?talk to the local service department for the brand ( of mixer ).

author: singapol
author_rank: Frequent Contributor
timestamp: September 24, 2015, 03:44:11 am
content: You can check it with meter if the pins are shorted. The part number is on the front, desolder it or snip the pins off.

author: XOIIO
author_rank: Super Contributor
timestamp: September 24, 2015, 04:05:45 am
content: Quote from: IconicPCB on September 24, 2015, 03:39:49 amAh true. Unfortunately it's somewhat old but I'll see if info has been released on it, maybe a patent for the board would have the schematic.

author: fivefish
author_rank: Frequent Contributor
timestamp: September 24, 2015, 04:26:40 am
content: Could be a triac... speed control for the motor?

author: XOIIO
author_rank: Super Contributor
timestamp: September 24, 2015, 04:38:29 am
content: Quote from: fivefish on September 24, 2015, 04:26:40 amYeah that would make more sense, though that probably means it will be much harder to figure out what it is if I can't find that info.

author: codeboy2k
author_rank: Super Contributor
timestamp: September 24, 2015, 04:55:36 am
content: Being that it's a blender with on/off switch and a speed controller, I suspect that it's just a simple SCR motor speed controller.Looking at the connections, I can see that it is VERY similar to the attached schematic (but this is NOT the schematic for your blender controller).There is an SCR with Cathode, Anode and Gate in that same order. You can see the the diodes feeding the gate, and the anode and cathode going to X1 and X4 through the switch S1. You can see the main speed controller and the 2 trimmer pots wrapped around the emitter/base of Q2.Without drawing up my own schematic (which is easy enough to do), you can trace it out and see that it's similar enough to the schematic of the motor speed controller to say it's likely an SCR, with Cathode/Anode/Gate in that order.It's not likely a TRIAC since TRIACs often need a DIAC or another SCR to trigger them, and this board just has a single transistor gate driver.If you can see any part of the original part number, and knowing it's an SCR, you can try to look it up on a datasheet site. Otherwise, just replace it with any SCR in a TO-220 package that can handle the motor current and voltage. For Canada you should use at least a 200V SCR, and current rating depends on the motor. Or you can just use a 400V/15A one then you can be sure it will work for your blender motor.

author: SeanB
author_rank: Super Contributor
timestamp: September 24, 2015, 11:05:03 am
content: Needs to be a sensitive gate SCR, so you will need to buy the TIC106D or a C106D , which are both sensitive gate and which come in that thin tab package. Buy a few, as they will pop with any fault on the motor, and as the SCR fasiling would have sent a pretty big pulse out the gate change D1 and C1, though C1 would likely have survived, but will be cheap enough to change. you can use a 1N4004 for D1, it will survive the next SCR blowing up, which the 1N4148 in there might not have.

author: amyk
author_rank: Super Contributor
timestamp: September 24, 2015, 02:31:43 pm
content: Find the other piece of the casing, the part number will be on it.

author: AF6LJ
author_rank: Unknown
timestamp: September 24, 2015, 02:41:13 pm
content: Examine the motor very carefully I suspect the motor opened up an armature winding and the resulting spike took out the thyristor. My money is also on that being an SCR.

author: XOIIO
author_rank: Super Contributor
timestamp: September 24, 2015, 07:48:47 pm
content: Quote from: amyk on September 24, 2015, 02:31:43 pmCouldn't find it unfortunately, the thing wasn't sealed up very well so it probably just fell out.

author: SeanB
author_rank: Super Contributor
timestamp: September 24, 2015, 08:04:25 pm
content: Pretty likely it was a C106B or D, only difference is one is a 200V part ( B) while the D is rated for 400V. I have been using them in impulse sealer’s to replace the hard to get locally TO92 SCR they use. Cheap as well, and just needs a little work, along with cutting the tab off, to fit the board layout.

author: XOIIO
author_rank: Super Contributor
timestamp: September 24, 2015, 08:07:02 pm
content: Hmm, only options locally are here.http://www.be-electronics.com/SearchResults.asp?Search=triacProblem is the only one that mentions sensitive is the NTE5609, which just says "moderate sensitivity" and is only 8 amps.I tried checking datasheets for ones that have suitable voltage and amperage ratings but I can't tell if they have sensitive gates or not .NTE564 - 10 ampNTE5645 - 20 ampQ6015L5 - 15 amp, possibly sensitive gate? Specs from mouser below.On-State RMS Current - It RMS: 15 ANon Repetitive On-State Current: 167 A, 200 ARated Repetitive Off-State Voltage VDRM: 600 VOff-State Leakage Current @ VDRM IDRM: 50 uAOn-State Voltage: 1.6 VHolding Current Ih Max: 70 mAGate Trigger Voltage - Vgt: 2.5 VGate Trigger Current - Igt: 50 mAMaximum Operating Temperature: + 125 CMounting Style: Through HolePackage / Case: TO-220-3Minimum Operating Temperature: - 40 CNormally I would order online but it will take quite a while to get here, and I will be going on holidays soon, probably before it arrives. The long tab isn't a critical aspect.Edit: ah crap wait, SCR, so probably not suitable at all, damn.

author: XOIIO
author_rank: Super Contributor
timestamp: September 24, 2015, 08:15:30 pm
content: Hmm, they do carry the S8015L (http://www.mouser.com/ProductDetail/Littelfuse/S8015L/?qs=zHiv0nsVGmoEPlhs%252bvi6sQ%3D%3D), perhaps that would be a suitable alternative?

author: SeanB
author_rank: Super Contributor
timestamp: September 24, 2015, 08:36:11 pm
content: S8015L will probably work there, not exactly stellar in the gate current, but at under 30mA hopefully you get some sensitive ones. Replace D1 in any case, it will probably be faulty.

author: XOIIO
author_rank: Super Contributor
timestamp: September 24, 2015, 09:02:19 pm
content: Quote from: SeanB on September 24, 2015, 08:36:11 pmAlright, cool. I imagine for something like a mixer it's not super critical anyways.

author: XOIIO
author_rank: Super Contributor
timestamp: September 24, 2015, 09:07:01 pm
content: Sigh, still have to wait until next week for them to get them in, typical :/

author: XOIIO
author_rank: Super Contributor
timestamp: September 29, 2015, 03:57:31 pm
content: Well, got the part in, replaced the electrolytic and a couple diodes that tested bad, and the thing is still dead, not getting any output, not much to go on from here except the small transistor package, it's a 2n5210 amplifier, and I won't be able to get that locally, so looks like it's waiting a couple weeks for the part. Once I have that though I can replace pretty much everything but those trim pots (both of which seem fine)