Does anyone know where to find diodes for this meter? They are 1n444B, one is broke. The meter also reads low tried adj. but still no good.

Thank you

 

Texas Instruments cross references to 1N4005. A common rectifier diode.


You don't need to post the same question in multiple forums.

 

Texas Instruments cross references to 1N4005. A common rectifier diode.
View attachment 332139

You don't need to post the same question in multiple forums.

It is a glass body diode. They are two that are across the meter. It may not be a B could be an 8. Any ideals?

 

Here is the schematic. D3 & 4.

 

It is a glass body diode. They are two that are across the meter. It may not be a B could be an 8. Any ideals?

Texas Instruments classified 1N444B as a silicon rectifier diode. Package type isn't relevant in this application. With D3 and D4 anti-parallel to the meter, my opinion is that they were over specified. A 500V reverse breakdown voltage is overkill. It's also very unlikely that they needed to be rated for 1A.

 

Relax! Those two diodes are there to protect the meter movement, they do not have a significant effect on performance or calibration.

 

I would think diodes 1N4148 would work they are often used for that purpose. You want very low reverse leakage.

 

I see that 38 uA is expected to flow through the meter movement. My opinion changed: 1N4148 or any small signal silicon diode should be fine.