Arduino Forum

Using Arduino => General Electronics => Topic started by: Shandy on May 10, 2019, 06:18 pm

Title: Identify the resistor type
Post by: Shandy on May 10, 2019, 06:18 pm
Can anyone tell me a little about these resistors such as type and characteristics.

Regards, Chris.
Title: Re: Identify the resistor type
Post by: MrMark on May 10, 2019, 07:12 pm
OP's photo:
(https://forum.arduino.cc/index.php?action=dlattach;topic=615151.0;attach=307693)

I believe those (R1-R8) are Metal-Oxide Varistors (MOV) intended to suppress large voltage transients coming in on the serial interface lines.

https://www.littelfuse.com/~/media/electronics/.../littelfuse_varistor_catalog.pdf.pdf (https://www.littelfuse.com/~/media/electronics/.../littelfuse_varistor_catalog.pdf.pdf)
Title: Re: Identify the resistor type
Post by: MarkT on May 10, 2019, 09:30 pm
Given the big chip is a quad UART with FIFO, this is likely a modem board and they are almost certainly MOVs to protect from lightning and other voltage spikes as MrMark suggests.
Title: Re: Identify the resistor type
Post by: Paul__B on May 11, 2019, 12:16 am
Which indicates this is not your average consumer-grade interface card by any stretch of the imagination.
Title: Re: Identify the resistor type
Post by: Shandy on May 11, 2019, 06:13 pm
You would be correct this is from a particle size analyser interface controller used in the labs I wanted to bin the electronics inside because the enclosures are stainless steel.