Doulbe-sided codes on Tantulum capacitors

[Bobertsawesome]

Hi there,

This one stumped me as I have never seen this marking method before, nor could I find info on the web regarding a double-sided code marking.

1st side 104-e5m , 2nd side 720-rac (same capacitor)

I assume it is 100nf, but not sure what or how to find the voltage rating. Included here are the photos for relevance:

[garrettm]

I believe that is a ceramic capacitor, not a tantalum. Tants have a polarity marking which this part does not have.

100 nF sounds right: 104 => 10*10^4 pF = 10*10^-8 F = 100 nF.

As to the voltage rating, good question. I couldn't find anything for e5m or RAC as a part name. Those also don't line up with the voltage/tolerance codes either.

Regardless, what is the measured voltage in circuit? Assuming it was derated 20-50%, that at least gives you a start.

Are you replacing a bad part or something else?

[fzabkar]

E5M appears to be a temperature coefficient.

https://www.ebay.com/itm/10pcs-Ceramic-Capacitor-50V-1uF-20-E5M-Radial-NOS-Free-Shipping-USA-/154017117597
https://en.wikipedia.org/wiki/Ceramic_capacitor#Class_1_ceramic_capacitors
https://electronics.stackexchange.com/questions/241232/what-does-the-3-figure-code-below-the-value-code-mean

[Bobertsawesome]

I believe that is a ceramic capacitor, not a tantalum. Tants have a polarity marking which this part does not have.

100 nF sounds right: 104 => 10*10^4 pF = 10*10^-8 F = 100 nF.

As to the voltage rating, good question. I couldn't find anything for e5m or RAC as a part name. Those also don't line up with the voltage/tolerance codes either.

Regardless, what is the measured voltage in circuit? Assuming it was derated 20-50%, that at least gives you a start.

Are you replacing a bad part or something else?

You are definitely correct, it threw me off considering the rest of the caps are tants. The circuit is fine, needed some minimal repairs due to degradation over 25+ years. Figured I'd recap at the time too. I suppose I'll just check the voltage to the cap, but was wondering more in the long run what the dual codes meant.