Unknown zener

[ValleyJim]

Hi all

I am trying to repair my old buffalo tools 21.6v battery charger. I have tried to find a schematic but haven't been able to find one so I am getting down to trying to identify the different components. I have most of them identified but there is a zener diode that has the markings "C6V5T" and I have not been able to find anything on this marking.

Has anyone seen this before or has anyone seen a schematic for this?

Thanks in advance!
Jim

 

[alfa88]

No schematic but I could guess at the value. 6.5Volts. You would also need to know how much Amperage the diode will handle. No Idea. To positively pinpoint the voltage of the Zener (assuming it is good) you need a power supply, 1k resistor and Voltmeter. Clip leads would help.Connect as shown. Starting at the lowest voltage slowly raise the voltage until the reading levels out. You now have your answer.

 

[ValleyJim]

I am working on putting together a schematic now.

6.5 sounds good though. I tested the zener and I am getting an ohm reading going both ways so from what I know that should be a bad diode.

So I will probably see if I can get another one and see if that solves the problem.

Thank you for the quick reply!
Jim

 

[alfa88]

Keep in mind that the 6.5 Volt figure is only a wild guess. Bad Things could happen if it were wrong.
Are you using a digital meter to measure diodes? I usually get conflicting results using DVMs when Ohming out diodes. This is where analog meters shine.

 

[ValleyJim]

Actually I used an analog to test it first and with the zener I got the same reading both ways. I see why you are thinking 6.5v on that because it makes sense to me and that is what I was originally thinking. But it just kills me that there is not a schematic out there anywhere that I can find for this damn thing,

 

[alfa88]

An active test on the diode would confirm things but if you insist go with a 6.5@1Amp Zener then have a Voltmeter hooked up and be quick on the power switch. I sometimes get flack for my cowboy approach to electronics. No guts no glory I guess.