Author Topic: What's this please? (Component Advice) (Read 1227543 times)

blackbird · « **Reply #1651 on:** January 22, 2021, 10:26:47 pm »

Quote from: capt bullshot on January 22, 2021, 12:59:53 pm

The circuit looks like an attenuator for a balanced line.

Quote from: CJay on January 22, 2021, 01:03:46 pm

And very generously of the manufacturers, they left it unpotted so it should be possible to measure all the components.

Sometime life is so simple...

I did not look close enough (also had my mind on something else) and like CJay noticed I could have measured the individual components. Well, this evening I had the a bit of time (and a dmm with 4-wire probes) so that's what I did.

Quote from: PA0PBZ on January 22, 2021, 01:13:06 pm

My measurements: R1/2 = 153 $\$\Omega\$$ (all four are almost equal as they should be), R2 = 896 $\$\Omega\$$ .

Using calculations from this site an attenuation of 7dB (as is written on the note) gives a K factor of 3.5.
The calculated impedance is 550.8 $\$\Omega\$$ . If I measure (with a dmm, so with DC) the resistance over points Vin and over Vout (in the illustration given by PA0PBZ) I get about 1.2k $\$\Omega\$$ on both.

So maybe the attenuation is not 7dB? A reverse calculation of K (with Z=1.2k $\$\Omega\$$ ) gives a K=5/3 and this gives an attenuation of 3.3dB.... Hmm, was the attenuation on the note wrong of did I screw-up my measurements and/or calculations?

It is getting late so first a good night sleep. $:=\$

vk6zgo · « **Reply #1652 on:** January 23, 2021, 05:11:12 am »

Quote from: blackbird on January 22, 2021, 10:26:47 pm

Quote from: capt bullshot on January 22, 2021, 12:59:53 pm
The circuit looks like an attenuator for a balanced line.
Quote from: CJay on January 22, 2021, 01:03:46 pm
And very generously of the manufacturers, they left it unpotted so it should be possible to measure all the components.

Sometime life is so simple... I did not look close enough (also had my mind on something else) and like CJay noticed I could have measured the individual components. Well, this evening I had the a bit of time (and a dmm with 4-wire probes) so that's what I did.

Quote from: PA0PBZ on January 22, 2021, 01:13:06 pm

My measurements: R1/2 = 153 $\$\Omega\$$ (all four are almost equal as they should be), R2 = 896 $\$\Omega\$$ .

Using calculations from this site an attenuation of 7dB (as is written on the note) gives a K factor of 3.5.
The calculated impedance is 550.8 $\$\Omega\$$ . If I measure (with a dmm, so with DC) the resistance over points Vin and over Vout (in the illustration given by PA0PBZ) I get about 1.2k $\$\Omega\$$ on both.

So maybe the attenuation is not 7dB? A reverse calculation of K (with Z=1.2k $\$\Omega\$$ ) gives a K=5/3 and this gives an attenuation of 3.3dB.... Hmm, was the attenuation on the note wrong of did I screw-up my measurements and/or calculations?

It is getting late so first a good night sleep. $:=\$

OK, terminate the "V out" terminals with 600 Ohms..
Now looking at the "V in" terminals you will see "near as dammit" 600 Ohms.
Swap the termination & meter ends, & you will the see the same resistance value.

The attenuation figure only works when the attenuator is terminated by, (& fed with a source of) the correct
impedance, so it looks like a 600 Ohm device.

Otherwise, all you see is a resistive network.

blackbird · « **Reply #1653 on:** January 23, 2021, 09:31:58 pm »

Quote from: vk6zgo on January 23, 2021, 05:11:12 am

OK, terminate the "V out" terminals with 600 Ohms..
Now looking at the "V in" terminals you will see "near as dammit" 600 Ohms.
Swap the termination & meter ends, & you will the see the same resistance value.

The attenuation figure only works when the attenuator is terminated by, (& fed with a source of) the correct
impedance, so it looks like a 600 Ohm device.

Otherwise, all you see is a resistive network.

Ah, off course, I forgot all about the fact of the termination. I did indeed see nothing more than the resistive network. Tried with terminating Vout with 600 $\$\Omega\$$ and measured (with only dmm) (pure resistive) about 750 $\$\Omega\$$ on the Vin.
My signal source can only output at 50 $\$\Omega\$$ . What should be the most practical way to match the impedance of my signal source to 600 $\$\Omega\$$ ?

vk6zgo · « **Reply #1654 on:** January 24, 2021, 05:18:10 am »

Quote from: blackbird on January 23, 2021, 09:31:58 pm

Quote from: vk6zgo on January 23, 2021, 05:11:12 am
OK, terminate the "V out" terminals with 600 Ohms..
Now looking at the "V in" terminals you will see "near as dammit" 600 Ohms.
Swap the termination & meter ends, & you will the see the same resistance value.

The attenuation figure only works when the attenuator is terminated by, (& fed with a source of) the correct
impedance, so it looks like a 600 Ohm device.

Otherwise, all you see is a resistive network.

Ah, off course, I forgot all about the fact of the termination. I did indeed see nothing more than the resistive network. Tried with terminating Vout with 600 $\$\Omega\$$ and measured (with only dmm) (pure resistive) about 750 $\$\Omega\$$ on the Vin.
My signal source can only output at 50 $\$\Omega\$$ . What should be the most practical way to match the impedance of my signal source to 600 $\$\Omega\$$ ?

You could make up a 50 : 600 Ohm matching pad, or do it the rough way, with a series 550 Ohm resistor.

Yansi · « **Reply #1655 on:** January 29, 2021, 11:01:50 pm »

Anyone any idea, what this old IC may be?

Marked as "gate array GA67A" in one of the documents.

After a bit of searching around, I am out of ideas. Couldn't find anything in PLCC68 that would have at least those three VCC/GND pairs in the corners.

helius · « **Reply #1656 on:** January 30, 2021, 04:26:04 am »

A component labeled "gate array" is a custom integrated circuit. They were also called Uncommitted Logic Arrays (ULAs).
Similar to today's FPGAs, but instead of being programmed electrically, they were programmed at the fab by a customer lithographic mask, adding a metal interconnect layer to the standard wafer. The wafers were then tested, diced, and packaged and chips sent to the customer.

So if you see a device like this, it is usually not a part that was ever sold on the open market, even though it may have markings that are in a datasheet. The most common suppliers were companies like IDT, VLSI, Ferranti, Toshiba, and AT&T.

Yansi · « **Reply #1657 on:** February 16, 2021, 03:12:32 pm »

Likely a matched pair of transistors (guessing by the two triplets of pins) with custom part number mady by F... fairchild? Huh..

How about making some measurements? Start with diode tests. Find all PN junctions and mark their voltage drops.

Google search also came empty on my side, but I haven't tried hard enough.

PA0PBZ · « **Reply #1658 on:** February 16, 2021, 03:13:57 pm »

Not a real answer, or does it? https://www.eevblog.com/forum/projects/f5152-1-info/

nonsuchpro · « **Reply #1659 on:** February 16, 2021, 07:17:08 pm »

Quote from: PA0PBZ on February 16, 2021, 03:13:57 pm

Not a real answer, or does it? https://www.eevblog.com/forum/projects/f5152-1-info/

Shit. I'm getting old. I forgot I posted this! My bad

Yansi · « **Reply #1660 on:** February 17, 2021, 12:55:03 pm »

Where's the original post with the photos of the dual matched transistors?

PA0PBZ · « **Reply #1661 on:** February 17, 2021, 01:48:01 pm »

Looks like he removed the post in shame but if you follow the link I posted you can still admire them!

Yansi · « **Reply #1662 on:** February 17, 2021, 03:11:32 pm »

I thought deleting posts under which other posts has been already placed is forbidden/disabled on this forum. It makes a sh!tmess out of the discussion.

Either way this is not a good practice.

tszaboo · « **Reply #1663 on:** March 15, 2021, 02:07:27 pm »

Someone who can translate this:
https://lcsc.com/product-detail/Electronic-Accessories_Yanchuang-100-100-0-3_C499653.html
Are these ferrite sheets?

RoGeorge · « **Reply #1664 on:** March 15, 2021, 02:14:23 pm »

Quote from: NANDBlog on March 15, 2021, 02:07:27 pm

Someone who can translate this:
https://lcsc.com/product-detail/Electronic-Accessories_Yanchuang-100-100-0-3_C499653.html
Are these ferrite sheets?

Google can translate webpages and files too.

go to
https://translate.google.com/

and in the translate box paste the link to your datasheet pdf to translate
https://datasheet.lcsc.com/szlcsc/2003241132_Yanchuang-100-100-0-3_C499653.pdf

then click on the link that appears in the right side box, the box where usually sits the translated phrase
https://translate.google.com/translate?hl=&sl=auto&tl=en&u=https%3A%2F%2Fdatasheet.lcsc.com%2Fszlcsc%2F2003241132_Yanchuang-100-100-0-3_C499653.pdf

gamalot · « **Reply #1665 on:** March 15, 2021, 02:15:27 pm »

Quote from: NANDBlog on March 15, 2021, 02:07:27 pm

Someone who can translate this:
https://lcsc.com/product-detail/Electronic-Accessories_Yanchuang-100-100-0-3_C499653.html
Are these ferrite sheets?

Yes

gamalot · « **Reply #1666 on:** March 15, 2021, 02:22:16 pm »

ZH-FSMZR15

ZH = JiangXi ZhongHeng Industrial Ceramics Technology CO.,LTD

FS = ferrite sheets

MZ = Mn-Zn series

R15 = 0.15mm (ferrite thickness)

depot · « **Reply #1667 on:** April 12, 2021, 08:30:18 am »

I found some CO2 sensor modules, but I didn't get much application data for them.
Like, what to send to them over I2C or UART to make measurements, etc.
The datasheets are pretty dry. I ask for support from them but I guess they're busy.

Here are a couple things I wish I could use:
https://www.digikey.com/en/products/detail/amphenol-advanced-sensors/T6713/5027891
https://www.digikey.com/en/products/detail/kemet/USEQGSEAC82180/11504936

Or maybe I should ask for bigger picture component advice.
What do you do in this case, someone sells electronics that you think you want, but it's still tough to use?
I don't like this kind of situation. If I hack it together it's still a bad feeling, like I won't get support or the parts I use will disappear.

cdev · « **Reply #1668 on:** April 13, 2021, 01:28:06 am »

Quote from: Excavatoree on May 12, 2011, 02:47:01 am

Just a quick ID question - can anyone identify:

Diode: Marked 62T02 and GI9774 (both on one diode, two lines) Google is no help. About the size of a 1N4002

unknown device in TO-220 package: IR9502 International Rectifier's website doesn't recognize it.

The AVR Transstortester (AVRTT) can extract most of the relevant specs from unknown components. it does this incredibly well.

tsmith35 · « **Reply #1669 on:** April 13, 2021, 02:13:06 am »

Quote from: depot on April 12, 2021, 08:30:18 am

I found some CO2 sensor modules, but I didn't get much application data for them.
Like, what to send to them over I2C or UART to make measurements, etc.
The datasheets are pretty dry. I ask for support from them but I guess they're busy.

Perhaps this will be useful: https://www.14core.com/wiring-the-telaire-t6713-t67xx-a-carbon-dioxide-co2-sensor/
https://ec.kemet.com/environmental-sensors/ (look under "Important Links")

rsjsouza · « **Reply #1670 on:** April 13, 2021, 08:47:09 am »

Quote from: cdev on April 13, 2021, 01:28:06 am

Quote from: Excavatoree on May 12, 2011, 02:47:01 am
Just a quick ID question - can anyone identify:

Diode: Marked 62T02 and GI9774 (both on one diode, two lines) Google is no help. About the size of a 1N4002

unknown device in TO-220 package: IR9502 International Rectifier's website doesn't recognize it.

The AVR Transstortester (AVRTT) can extract most of the relevant specs from unknown components. it does this incredibly well.

cdev, did you realize you are one month away from quoting a ten year old post?

It is crazy how old EEVBlog is becoming... (I have been here for almost that time).

cdev · « **Reply #1671 on:** April 16, 2021, 11:29:52 pm »

Quote from: rsjsouza on April 13, 2021, 08:47:09 am

Quote from: cdev on April 13, 2021, 01:28:06 am
Quote from: Excavatoree on May 12, 2011, 02:47:01 am
Just a quick ID question - can anyone identify:

Diode: Marked 62T02 and GI9774 (both on one diode, two lines) Google is no help. About the size of a 1N4002

unknown device in TO-220 package: IR9502 International Rectifier's website doesn't recognize it.

The AVR Transstortester (AVRTT) can extract most of the relevant specs from unknown components. it does this incredibly well.

Its crazy indeed, in a good way. Ive learned so much stuff here. I have been trying to remember the reason I initially came here. I remember seeing Dave make a video saying about he was going to devote himself to his business full time, and I found i really liked watching his in your face style.

But where did I see it.. LOL..

I'm sorry about quoting such an old post. I realized that after I hit send.

Quote from: rsjsouza on April 13, 2021, 08:47:09 am

cdev, did you realize you are one month away from quoting a ten year old post?

It is crazy how old EEVBlog is becoming... (I have been here for almost that time).

its crazy how old I am getting, but I'm pretty happy. I have my sweetie and my health, and interests.. So I can't complain I am so much more fortunate than so many of us right now. I wish I could do more to help .

tsmith35 · « **Reply #1672 on:** May 07, 2021, 01:15:37 am »

This is the aftermath of connecting 120VAC to a board designed for 24VDC (not me this time!). 3 components let loose magic smoke, of which 2 are unidentified (the 3rd was a 24V TVS on the other side of the board, but it was well-marked).

The mystery components here are VR6 and VR7. Neither component has any markings on them. Plain black SMDs that look just like VR8. Tested the dead components with diode mode on my meter and got 1.5V and 1.6V VF for VR7 postmortem. Got 0.5V and 0.6V VF for VR6 postmortem. VR7 measures about 4.5mm wide x 5mm long, while VR6 measures about 2.5mm wide x 3mm long. Both have a few hundred ohms resistance (depends on polarity) in either direction, though I don't recall exactly how much.

Any ideas? Neither device seems to match diodes in either appearance or dimensions, and the mysterious "VR" designation and "00" don't help any.

Cubdriver · « **Reply #1673 on:** May 07, 2021, 01:30:57 am »

Quote from: tsmith35 on May 07, 2021, 01:15:37 am

This is the aftermath of connecting 120VAC to a board designed for 24VDC (not me this time!). 3 components let loose magic smoke, of which 2 are unidentified (the 3rd was a 24V TVS on the other side of the board, but it was well-marked).

The mystery components here are VR6 and VR7. Neither component has any markings on them. Plain black SMDs that look just like VR8. Tested the dead components with diode mode on my meter and got 1.5V and 1.6V VF for VR7 postmortem. Got 0.5V and 0.6V VF for VR6 postmortem. VR7 measures about 4.5mm wide x 5mm long, while VR6 measures about 2.5mm wide x 3mm long. Both have a few hundred ohms resistance (depends on polarity) in either direction, though I don't recall exactly how much.

Any ideas? Neither device seems to match diodes in either appearance or dimensions, and the mysterious "VR" designation and "00" don't help any.

My guess would be that they were surface mount varistors, though I can't guess at their value other than a withstanding voltage somewhat greater than what they're across.

-Pat

Abaku · « **Reply #1674 on:** June 13, 2021, 02:38:55 pm »

Hi all, I'm new to the forum. The burned resistor pictured is from a heated blanket controller. I'd rather replace the resistor than the whole blanket. I used the colour coding on the one below it (they're the same), with the help of a website, to help me find the resistor I needed on ebay. The discription for the listing is as follows:

Quote

Metal Film resistors 60 different value, 5 different quantity
All resistor have 1/4W - 0.25W power dissipation and 1% tolerance rating

Values: 10 Ohm - 1 MOhm
Quantities: 1-10-20-50-100 pcs

I chose the 510 ohm resistor, and that's the one you see pictured, which is obviously very different in size but the bands look the same colour. Can anyone help me figure out which type of resistor I need to buy? Thanks


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Author Topic: What's this please? (Component Advice) (Read 1227543 times)

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