(Topic ID: 305830)

Resistor value drift - What’s ok?

By Nacman

2 years ago

Topic Stats

2 posts
2 Pinsiders participating
Latest reply 2 years ago by Markharris2000
No one calls this topic a favorite

You

You are not signed in!

Find in topic

Linked Games

No games have been linked to this topic.

I’m still chasing the chattering issue an since the solenoid in question sits on the auxiliary driver 8 board I’m focusing my efforts there.

The original Williams board blew a transistor so I replaced it with a rotten dog board. I don’t know if that figures into the equation of the chattering issue I have. So the only way that I have to test that theory is put the original board back in. I decided to test every component on the original board to see if burning up the tip102 had any other casualties.

There are 8- 2.7 Kohm resistors behind the diode behind the TIP102.

I only have two that register 2.7 K and the rest are around 2000 with one being 1800. I’ve also checked the pre-driver transistor and all of them check fine per instructions I found on here. All the other components which are mostly diode’s and transistors check within one percent of tolerance.

So my question is should I change out the ones that are way off and what is their real purpose?

OP
Quoted from Nacman:
I’m still chasing the chattering issue an since the solenoid in question sits on the auxiliary driver 8 board I’m focusing my efforts there.
The original Williams board blew a transistor so I replaced it with a rotten dog board. I don’t know if that figures into the equation of the chattering issue I have. So the only way that I have to test that theory is put the original board back in. I decided to test every component on the original board to see if burning up the tip102 had any other casualties.
There are 8- 2.7 Kohm resistors behind the diode behind the TIP102.
I only have two that register 2.7 K and the rest are around 2000 with one being 1800. I’ve also checked the pre-driver transistor and all of them check fine per instructions I found on here. All the other components which are mostly diode’s and transistors check within one percent of tolerance.
So my question is should I change out the ones that are way off and what is their real purpose?

Resistors are rated for accuracy, commonly from 1% to 10%. Most commercial products use 10%. Your values are way off for ANY tolerance marking! The fourth band is a color, usually gold for 5% or silver for 10%. Eliminate a variable and swap the out of spec resistors. Get some 5% replacements. Metal if you can find, since carbon tend to drift over time.

Reply

Wanna join the discussion? Please sign in to reply to this topic.

Hey there! Welcome to Pinside!

Donate to Pinside

Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!

Help – Contact – About Pinside – Support Pinside – Top