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Home > Forums > Electrical / Electronic Engineers > Activities > Microwave & electromagnetic engineering Forum

Unknown component

thread239-206654
Read More Threads Like This One
Leiser (Automotive)
10 Jan 08 11:59
Does anyone know what this component is? please see attached picture

This component is in a AM car amplifier. It is connected to VCC and ground in parallel with a electrolitic capacitor, this block is where the amplifier is feed. It could be a transil, not sure, some kind of protection.

geekEE (Electrical)
10 Jan 08 12:30
I can't open a .CPT file. What is that? Corel?  You'd probably get a better response if you post the picture in .JPG or .GIF format.  
 
Skogsgurra (Electrical)
10 Jan 08 12:42
Is this for a product you are working on?

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
biff44 (Electrical)
10 Jan 08 18:14
Boy,that is a poor quality picture!

It is hard to see, but my guess would be that it is some sort of surface mount ceramic carrier, with a semiconductor device wirebonded inside of it with some epoxy on top.  What does it look like looking straight down with a microscope.
Leiser (Automotive)
11 Jan 08 4:38
Hi again,

thanks for your replies.

I have taken a couple of pictures with the microscope. However, I found it difficult to take a clear shot. The attached document has the two pictures and a simple sch.

This component is placed in an automotive FM LNA. There is no regulation as the amplifier is fed from the battery or the ouput of the radio using phatom feeding.

Any ideas?  
VE1BLL (Military)
11 Jan 08 7:36
It's a monitoring device installed on behalf of the government. They're watching your every move. winky smile

More seriously, can you desolder it and then measure it? Or temporarily cut some traces and do the same thing?

Obviously it's something to do with the power supply (making the voltage better in some way), and for that reason is slightly... ...boring. What I'm saying is that you could probably conclude that it is an unknown thing-a-ma-bob across the rails, and then carry on with the rest of the circuit.
Skogsgurra (Electrical)
11 Jan 08 8:24
I repeat: Is this a product you are working on? The question seems to be quite far away from an engineering question. Is it a one off amplifier you are trying to repair?

What about trying Tek-Tips?

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
Leiser (Automotive)
11 Jan 08 8:36
Hi all,

I am working designing LNA´s. I have seen this component in other LNA´s regularly and I was wondering what does it do, so I can learn more!.

Anyway, thanks for you comments.
Skogsgurra (Electrical)
11 Jan 08 9:43
Since it is a car application, it seems to be something that takes care of a load dump or just a transient suppressor.

Seems to be physically small for a load dump, though.

But, given that we cannot read the photos very well, it is difficult to tell. Wouldn't a normal digital camera in macro mode produce a readable picture?

It would also be nice if you told us what an LNA actually is. Most people would guess a Low Noise Amplifier, but there is no way telling it. I guess there are dozens of meanings for LNA.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
Leiser (Automotive)
11 Jan 08 9:53
Yes, you are right. LNA stands for Low noise amplifier.

I tried to take a shot using the macro option but I think I have a problem with light.

I agree it looks is a transient suppressor. It seems that´s the farthers I will get.

Anyway thanks for your comments.
VE1BLL (Military)
11 Jan 08 10:07
Without a series resistance (none shown in the partial schematic), then it would be trying to protect the entire vehicle (at least back to the nearest fast-blow fuse).

That's fairly brave for a little tiny surface-mount fellow.
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