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Electronics => Beginners => Topic started by: Mad Professor on August 14, 2016, 11:24:51 am

Title: Mini-MELF Diode:
Post by: Mad Professor on August 14, 2016, 11:24:51 am
Hi All.

This is the 1st time I have had any dealing with Metal Electrode Leadless Face (MELF) components.

I think the component is a Mini-MELF Zener Diode. the only markings is a single blue band at one end.

I am trying to find details for a component that I think has failed or partly failed.
I think this diode is faulty as it seems to be pulling a signal rail up, but not fully.
With the diode removed the signal rail is at 0v, but with the diode in place it's at 12.6v, the supply rail is 28.8v.
The signal rail is between the output of a CNY17 (http://www.vishay.com/docs/83606/cny17.pdf) Optocoupler and the gate of a BUZ10 (http://www.uv.es/~maicasj/lcsp/ds/buz10.pdf) Power MOSFET.

Thanks for your time.

Best Regards.
Title: Re: Mini-MELF Diode:
Post by: GBowes on August 14, 2016, 05:14:55 pm
A little more information might be helpful if you want people to help.
I started to make some comments but there is really too little to go on.
Can you post a schematic at least of the connections to the opto outputs, the MELF in question, and the Mosfet gate and showing the supply rail and the "signal "rail


Hi All.

This is the 1st time I have had any dealing with Metal Electrode Leadless Face (MELF) components.

I think the component is a Mini-MELF Zener Diode. the only markings is a single blue band at one end.

I am trying to find details for a component that I think has failed or partly failed.
I think this diode is faulty as it seems to be pulling a signal rail up, but not fully.
With the diode removed the signal rail is at 0v, but with the diode in place it's at 12.6v, the supply rail is 28.8v.
The signal rail is between the output of a CNY17 (http://www.vishay.com/docs/83606/cny17.pdf) Optocoupler and the gate of a BUZ10 (http://www.uv.es/~maicasj/lcsp/ds/buz10.pdf) Power MOSFET.

Thanks for your time.

Best Regards.