To find a unknown diode

[mmcs]

Have a Diode- through/hole-orange with black ring which looks like DigiKey’s 1N414 but is not.

The diode in question is labeled with what appears to be the manfacturer’s ID (dipicted by drawing attached below) plus the number 24 58. This diode is after a series of resistors (x2) 1st res. is 4.7k ohms (121Vac to 107VAC), 2nd resistor 47Kohms bringing the 107 VAC down to 15 Vac.

Here it enters the Diode and brings the voltage down to 5.x VAC. . This then goes to a IC Binary7-Bit 14 dip, CD4024BE (mfr pn)- 296-2042-ND, (digikey pn).

Any help very much appreciated

Gary

[David_1528]

Hi mmcs,

Welcome to the TechForum.

My best guess is that the part is marked with a logo (I believe you mentioned elsewhere an “F”) along with a “24” and then a “5B” rather than “58”.

See this part:

• 1N5245BTR Onsemi 15V zener diode
  
  

The “F” would most likely be for Fairchild (now part of Onsemi) and “245B” is the marking for a 15V zener, as indicated in this datasheet:

The 15V does not necessarily jive with your measurement of 5.x Vac, but I suspect that if you looked at the actual signal with an o-scope, it might indicate a zenering around 15V during the reversed biased portion of the AC wave, and around 0.7V ~ 1.0V during the forward biased portion of the wave.

Sounds like your 7-bit counter is counting and dividing down the positive going portion of the AC waveform.

[mmcs]

Wow! that was fast. You are good at what you do. Thanks…

The “F” as you called it looked almost like an extended 4. Never though about and F. The 24 are on on level and the 5 8/B are on another. am going to have to break down and get a scope if I keep this up.

I will assume that DigiKey has these diodes on hand.

Thanks again…

Gary

[Kristof_2649]

The old Fairchild logo looked like this which if you tilt your drawn logo sideways looks similar.

Example of the logo on a part.

[David_1528]

Yes, I linked to the part number above.

Here it is again:

• 1N5245BTR Onsemi 15V zener diode