Hello,

I found this in an email:

Hello,
I have 2 really dumb questions and am hesitant to post.
Could you help me out?
1. Diode identification; I have a LCD clock from a honda and am trying to identify the diode in the board. The diode is a small black box. On the board next to the diode it says 5154. On the diode is printed SG9B, or SG98, or 5G9B, or 5G98 I can not tell it is so small.
2. The second question is even dumber. When hooking up the clock to a pyramid 35 amp power supply, the clock lights up fine but the ammeter reads almost 0 amps. I assumed that the meter would go to 35 amps as it is supposed to deliver that amount. Is the supply delivering the desired amperage? I want to test the clock with high amperage as to simulate what would happen if hooked up to a car battery. Thanks, please let me know if I should post, etc. Just a little embarrassed by my lack of knowledge here.

As I do not answer emails I make the post here so everybody can give replies.

Bertus

 

Dont be embarrassed. We all start somewhere.

Amps are not given, like voltage.

If you have a 35Ah battery that is 12v, And you want to operate a little LED and resistor off of it, the battery will push out 12v but the LED will only DRAW .02 milliAmp.

SO, your ammeter should not read anything UNTIL amps are being drawn.

As for the printing on the circuit board, It likely is a key or place marker/legend.

If this is a box, It sounds like a rectifier diode or a bridge rectifier.

A photo would help greatly.

Is this it?:
http://www.google.com/url?sa=t&sour...6qGnV1I-1sgIKb9TQ&sig2=AFTEL5-_f6N0rihsYPkTGw

 

Thanks! I didn't realize that this had been posted until I googled the question and saw that bertus published it. I'll send you the pic.

 

http://img828.imageshack.us/i/diode.jpg/

I hope this pic upload works. Thanks for any help!

 

It is kind of hard to make out, but it appears to be a standard surface mount diode.

Texas Instruments website doesn't respond with any 'SG' part numbers.

 

Thanks for checking! I'll read more on how to test this thing (voltage, etc) to get the specs. I am hoping that a few generic surface mount diodes with the proper specs will work.

 

If its dead, there isnt much testing that will help..

If the board is already dead, I would try a standard 1N4004 type diode for the job.

Cant hurt.....much.