Author Topic: What's this please? (Component Advice)  (Read 362294 times)

0 Members and 1 Guest are viewing this topic.

Offline requim

  • Regular Contributor
  • *
  • Posts: 209
  • Country: us
Re: What's this please? (Component Advice)
« Reply #100 on: January 22, 2012, 06:49:19 pm »
Black in the middle assuming you mean along the axis. It's really hard to see using a 10X loupe. I may be wrong on the color.
« Last Edit: January 22, 2012, 06:52:25 pm by requim »
 

Offline amspire

  • Super Contributor
  • ***
  • Posts: 3633
  • Country: au
Re: What's this please? (Component Advice)
« Reply #101 on: January 22, 2012, 11:57:51 pm »
My guess is it is not a small signal diode.

If you can work out some of the circuit around the diode, we could then make a more educated guess.

If you look carefully, is there a gap inside the glass between the two electrodes, or is there definitely a thin slice of some silver looking metal between them?

If there is a gap, it is fine and it can go back in the circuit.

Richard
 

Offline Rufus

  • Super Contributor
  • ***
  • Posts: 2094
Re: What's this please? (Component Advice)
« Reply #102 on: January 23, 2012, 01:37:16 am »
I'm sure this will be dead easy for virtually everyone on here.  Is this a diode? fuse?  I've tested it for both resistance and in diode mode and all I get is 0L so I assume it's blown.  Is that correct? If so, is there some way I can identify the specs on it so I can replace it?

KitchenAidPart.jpg ? Are you trying to make us guess?

I'll guess it is from a variable speed motor control circuit and it is a diac.
 

Offline requim

  • Regular Contributor
  • *
  • Posts: 209
  • Country: us
Re: What's this please? (Component Advice)
« Reply #103 on: January 23, 2012, 01:50:19 am »
@Rufus - no this isn't a game I just don't know what it is.  It's from a KitchenAid mixer on a small PCB (the only PCB) that has about 7 resistors, two caps (~100 uF and 23uF) and this part.  The other parts seem to be fine so I'd like to make sure this one is too before I starting looking elsewhere for a problem.  The mixer was used 2 - 3 times before it broke.  Unfortunately we didn't open the box and use the mixer until long past the warranty period.

@amspire - I don't see a gap or silver.  All I see is black in the middle. Without a microscope I don't know that I can give a better description of what I'm seeing in the middle. I've tried it under a 10X hastings triple and that's the best I can come up with.
 

Offline G7PSK

  • Super Contributor
  • ***
  • Posts: 3610
  • Country: gb
  • It is hot until proved not.
Re: What's this please? (Component Advice)
« Reply #104 on: January 23, 2012, 02:04:23 am »
Is it a thermal fuse?
 

Offline amspire

  • Super Contributor
  • ***
  • Posts: 3633
  • Country: au
Re: What's this please? (Component Advice)
« Reply #105 on: January 23, 2012, 02:13:34 am »
Can you draw the circuit? A photo of the board and the mixer internals would help.  Rufus's suggestion of a diac is a good one, but that would mean there has to be a triac or thyristor.

I was thinking it may be a spark gap surge arrestor which may be directly across the motor. If it is, it will look like an open circuit, and it will be fine as long as the glass is not broken, and it can go either way - it would not be polarized.

I assume the mixer somehow can vary the motor speed. It could use different resistors, or capacitors to affect the speed, or it could be there is more circuitry you cannot see - perhaps built into the actual speed control switch or knob.

Also, how has it failed?

Richard
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15034
  • Country: za
Re: What's this please? (Component Advice)
« Reply #106 on: January 23, 2012, 02:41:08 am »
This is not so much as what is it, more does any one have some data on it. It is marked as an Oxygen probe the BNC has the legend probe master on it. I have contacted probe master but all they can tell me is that it was made for another company some years ago and they no longer have any data on it. It would appear to be a 10X probe with a gold plated banana plug on the end which has a spring loaded retracting sheath. I purchased it on ebay for a small price with the idea that it might be useful as the basis for a high voltage probe or such like at some point.

That is an oxygen sensor, used to measure the concentration of oxygen in the air supplied to the sensor. Different to the oxygen sensor in your car in that this one generates a millivolt signal ( into a really high impedance, thus the 10x probe to use with a 1M input voltmeter) at ambient temperature, and giving an absolute reading of concentration. If it has been opened for a while it will have aged to near uselessness. It is basically a metal air battery, with some added temperature compensation built in to it that works at the correct load resistance.

Using the connector end to make a high voltage probe is good, just make sure the resistors you use to make the high voltage divider input side are rated for the voltage you will apply to them, and are mounted on a board that is totally clean, no solder residue at all. Preferable is to solder them together and clean before sliding them into a PTFE tube and filling it with an insulating epoxy to provide insulation.
 

Offline G7PSK

  • Super Contributor
  • ***
  • Posts: 3610
  • Country: gb
  • It is hot until proved not.
Re: What's this please? (Component Advice)
« Reply #107 on: January 23, 2012, 03:06:40 am »
Thanks for that SeanB. I had sort of guessed that it could be something like that But when I put the meter on it I just got a 9.13mohm reading from the gold plug to the center pin of the bnc it appears as OC from the gold plug to the bnc outer. The intention is to make a  thousand times probe with an attenuation network. But before I do that I will see if it will respond to pure oxygen from my cutting torch cylinder.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15034
  • Country: za
Re: What's this please? (Component Advice)
« Reply #108 on: January 23, 2012, 04:01:53 am »
It should generate a few millivolts if it is working, if exposed to atmosphere. T%hey are really expensive sensors when new, but have a very limited life once opened. 3 to 6 months is typical, and they cost upwards of $ 100 each. I did use one once, second hand, but did not buy a spare probe once I found out the price. Luckily the probe it came with was still hermetically sealed in a packet. See http://en.wikipedia.org/wiki/Electro-galvanic_fuel_cell for more about the cell construction.
 

Offline requim

  • Regular Contributor
  • *
  • Posts: 209
  • Country: us
Re: What's this please? (Component Advice)
« Reply #109 on: January 23, 2012, 04:09:15 am »
@amspire - What program can I use to make the schematic? Preferably simple and for the Mac, otherwise Linux or Windows is fine.

And yes I forgot the board does have a triac.  I removed it a while ago and forgot all about it when I made my original post.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15034
  • Country: za
Re: What's this please? (Component Advice)
« Reply #110 on: January 23, 2012, 04:24:04 am »
If it has a triac it most likely is a diac. Open circuit ( or pretty close to it) until you reach the breakdown voltage of around 30-40V when it switches on and has a low forward drop of a few volts across it, until the current drops below the holding current. Used as a trigger to do phase control for AC applications like motor speed controls or light dimmers.
 

Offline G7PSK

  • Super Contributor
  • ***
  • Posts: 3610
  • Country: gb
  • It is hot until proved not.
Re: What's this please? (Component Advice)
« Reply #111 on: January 23, 2012, 04:41:47 am »
Hi seanB I tried the probe on a meter it reads 1 to 1.4 mV and 1mV on the scope with a lot of noise from the mains etc, i guess the end is not screened, I will see what happens with pure oxygen. I only paid a few pence for it.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15034
  • Country: za
Re: What's this please? (Component Advice)
« Reply #112 on: January 23, 2012, 04:52:13 am »
Probably still working, the meter normally has a low pass filter on the input, as the time constant on these sensors is in the minute range. Try using a 1uF polypropylene or mylar unit across the unit when testing it to remove mains hum. Might take a few seconds for readings to stabilise  after a step change.
 

Offline G7PSK

  • Super Contributor
  • ***
  • Posts: 3610
  • Country: gb
  • It is hot until proved not.
Re: What's this please? (Component Advice)
« Reply #113 on: January 23, 2012, 04:56:06 am »
Thanks SeanB I will try that, Not sure what I will do with an oxygen probe at the end of the day though I am not into diving much to claustrophobic for me.
 

Offline requim

  • Regular Contributor
  • *
  • Posts: 209
  • Country: us
Re: What's this please? (Component Advice)
« Reply #114 on: January 23, 2012, 05:07:26 am »
@SeanB - How would I test the triac and diac?
 

Offline requim

  • Regular Contributor
  • *
  • Posts: 209
  • Country: us
Re: What's this please? (Component Advice)
« Reply #115 on: January 23, 2012, 05:08:44 am »
@amspire - The mixer will not turn on.  Dead as a doornail.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15034
  • Country: za
Re: What's this please? (Component Advice)
« Reply #116 on: January 23, 2012, 05:15:29 am »
Thanks SeanB I will try that, Not sure what I will do with an oxygen probe at the end of the day though I am not into diving much to claustrophobic for me.

Looking again, if it does not have anything under the heatshrink other than a connection or a resistor then it probably is an adapter for a probe, not the actual probe itself. Most would give a few hundred millivolts when working, so probably it is just the adaptor kit, so cut up for parts.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15034
  • Country: za
Re: What's this please? (Component Advice)
« Reply #117 on: January 23, 2012, 05:21:57 am »
@SeanB - How would I test the triac and diac?

Simplest test is by substitution. Before that check if the motor actually works, easy to do by shorting across the 3 pins of the triac, as you have removed the diac. If the motor runs at full speed you need a new triac and diac, the triac does need to be the same type, but the diac is pretty much interchangeable with any other diac, as they generally only have a single application. See http://en.wikipedia.org/wiki/DIAC for a little more.
 

Offline requim

  • Regular Contributor
  • *
  • Posts: 209
  • Country: us
Re: What's this please? (Component Advice)
« Reply #118 on: January 23, 2012, 04:07:46 pm »
Here's the schematic.  I tried running the motor and either I didn't hook things back up right or the motor doesn't appear to be working.  I'm in the process of taking it apart to dig a little deeper.

 

Offline amspire

  • Super Contributor
  • ***
  • Posts: 3633
  • Country: au
Re: What's this please? (Component Advice)
« Reply #119 on: January 23, 2012, 04:36:58 pm »
Your schematic does have a Triac, so that mystery part is probably a diac. The diac will look like an open circuit till you put its breakdown voltage across it. Could be something like 30V. It will then turn on and drop down to less then a volt until you disconnect it from the current.

There is a good chance it is OK. I would replace it in the circuit for now.

First thing is if you have the model with the circuit breaker, check that the circuit breaker is not open circuit. If it is, there should be a way to reset it.

Check the Triac for shorts or a cracked case. If it is not shorted, then there is a pretty good chance it is OK.

See if you can get any resistance in the motor winding as you turn the shaft. It could have a faulty brush or the winding has gone open circuit.

If you replace the motor with an old incandescent light bulb (40W or 60W would be good), you should be able to vary the brightness with the speed controller. If that works, then the problem is the motor. If it doesn't work, then the problem is on the PCB or the speed control.

Richard.
 

Offline requim

  • Regular Contributor
  • *
  • Posts: 209
  • Country: us
Re: What's this please? (Component Advice)
« Reply #120 on: January 23, 2012, 07:28:55 pm »
Problem solved.  No idea what I did that actually fixed it but it runs again.  Only idea I have is that the brushes were in wrong. Need to adjust it so it runs at the right speeds but it does turn on.  Thanks for all the help.
 

Offline requim

  • Regular Contributor
  • *
  • Posts: 209
  • Country: us
Re: What's this please? (Component Advice)
« Reply #121 on: February 02, 2012, 06:00:38 pm »
I pulled this IC from a Sony PlayStation 3 Slim power supply (EADP-200DP).  I've googled around and checked Octopart and can't find anything of note for it.

Here are the markings:

F --- Fairchild Semiconductor??
YAABE --- pretty sure this is a manufacturing code of some sort since the same chip on another power supply is YAPAA
DNP011 --- Figured this was the part number but can't find anything.  I've tried DNPO11, DNP011, and DNPQ11 (I tried Q before I looked at it under magnification.
NYE -- Manufacturer?

I figured this would be a common part, since it's just a basic SMPS, but I guess not, or I don't know how to look for it properly. Any help would be appreciated. 
 

Offline vk6hdx

  • Regular Contributor
  • *
  • Posts: 57
  • Country: au
    • vk6hdx - Twitter
Re: What's this please? (Component Advice)
« Reply #122 on: February 02, 2012, 06:44:43 pm »
I can't seem to find a datasheet for it either :-\ however it seems to come from Fairchild as I stumbled across this certificate of compliance for it.

http://www.fairchildsemi.com/coc/DN/DNP011.pdf
 

Offline requim

  • Regular Contributor
  • *
  • Posts: 209
  • Country: us
Re: What's this please? (Component Advice)
« Reply #123 on: February 02, 2012, 06:52:50 pm »
Well that's a start.  Maybe my best bet is to email Fairchild Semiconductor and ask them where I can buy them from.

Edit:  It looks as if the part has been EOL'd and is being replaced by DNP013.  Doesn't really matter much because I can't find anything regarding that chip either.
« Last Edit: February 02, 2012, 06:55:33 pm by requim »
 

Offline amspire

  • Super Contributor
  • ***
  • Posts: 3633
  • Country: au
Re: What's this please? (Component Advice)
« Reply #124 on: February 03, 2012, 12:40:52 am »
I think it is one of two things, and you can probably work out which one it is from the circuit.

As a guess, it is either an optocoupler device, or a MOSFET in a 8 pin DIP package. I don't think it is a regulator IC.

If it is an optocoupler then the two leads to the LED part will go to the secondary side of the transformer. Two or 3 wires from the other side of the optocoupler will go to the circuitry connected to the primary/mains side of the transformer.

If it is a mosfet, it will probably have pins shorted, and one pin will be connected to an output of the regulator IC. Another pin may go directly to a transformer winding.

Richard
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf