Can someone help me identify the two surface mount components inside the red box? I believe they are inductors, but I was not able to confirm this, nor to determine the values, with an internet search.

They are part of the power supply for a digital temperature controller.

Thanks in advance.

Jim
Kentucky, USA

 

I'd guess a diode or zener in a MELF package
/mike

 

Yes, seems to be a MELF package. Thanks for pointing me in that direction.

But I can't find any diodes that look anything like them. Likewise, I can't find any inductors or resistors that carry a two-bar marking code.

In circuit, with DMM in ohms mode, one of them acts like a 2K resistor. Across the other one, though, the DMM ohms value is above 1M and continuously rises slowly.

Guess I might have to take one out and fool around with it.

Jim

 

Likewise, I can't find any inductors or resistors that carry a two-bar marking code.

In circuit, with DMM in ohms mode, one of them acts like a 2K resistor. Across the other one, though, the DMM ohms value is above 1M and continuously rises slowly.

In-circuit measuring gives you probably wrong results. You'll have to take them off the board.

http://www.marsport.org.uk/smd/plasmelf.htm

Possibly this one? BYM12-150

 

My bet is a SMD power resistor or may be a zener diode

 

In-circuit measuring gives you probably wrong results. You'll have to take them off the board.

Yes, I'm sure you are correct. But I thought I would take a chance on learning something useful without first removing them

http://www.marsport.org.uk/smd/plasmelf.htm

Possibly this one? BYM12-150

I believe you have solved my mystery! Looks like they are Vishay ultrafast rectifier diodes BYM12-150 / EGL41C SuperRectifiers (150V, 1A). The Vishay datasheet says intended application is high frequency switching power supplies, which is precisely where they appear in my board.

Many thanks!

Jim

 

Hi Jim
You did a post a while back looking for a variable voltage controlled pot for a circuit that had 120VAC running thru the circuit. Did you ever find a solution to this. I have a similar application.

Rich