× A place to discuss hardware/software and diagnostic procedures

Attenuators!

  • Wood
  • Topic Author
  • Offline
  • Junior Member
  • Junior Member
More
04 Aug 2019 22:48 #32484 by Wood
Attenuators! was created by Wood
Can someone explain to me how you choose which attenuator to use? If you're not sure what the voltage spike is going to be on an ignition system do you just go with a 20:1? instead of buying both can I just get away with always using a 20:1? What's the drawback...less detail?

Please Log in or Create an account to join the conversation.

  • Andy.MacFadyen
  • Andy.MacFadyen's Avatar
  • Away
  • Moderator
  • Moderator
More
05 Aug 2019 01:17 - 05 Aug 2019 06:25 #32490 by Andy.MacFadyen
Replied by Andy.MacFadyen on topic Attenuators!
X20 is pretty much the standard for automotive work, the loss of resolution compared to an X10 isn't a major issue. I have even tried X100 and still got useful captures.

" Welcome to the 21st"


Last edit: 05 Aug 2019 06:25 by Andy.MacFadyen.

Please Log in or Create an account to join the conversation.

  • Andy.MacFadyen
  • Andy.MacFadyen's Avatar
  • Away
  • Moderator
  • Moderator
More
05 Aug 2019 06:28 #32498 by Andy.MacFadyen
Replied by Andy.MacFadyen on topic Attenuators!
Exploring this topic with a few test demos might be an idea next time I look at injector I will do some captures

" Welcome to the 21st"


Please Log in or Create an account to join the conversation.

  • Chad
  • Chad's Avatar
  • Offline
  • Moderator
  • Moderator
  • I am not a parts changer.
More
05 Aug 2019 07:00 #32499 by Chad
Replied by Chad on topic Attenuators!
It, really, depends on your scope. An Ignition coil control can spike up to 400 volts. Snap-on Scopes can handle a voltage spike of 400 volts, so no attenuator is needed. The Picoscope 4425 has a 200 volt limit, so a 10:1 attenuator is plenty.

"Knowledge is a weapon. Arm yourself, well, before going to do battle."
"Understanding a question is half an answer."

Please Log in or Create an account to join the conversation.

  • Andy.MacFadyen
  • Andy.MacFadyen's Avatar
  • Away
  • Moderator
  • Moderator
More
05 Aug 2019 08:04 - 05 Aug 2019 08:05 #32505 by Andy.MacFadyen
Replied by Andy.MacFadyen on topic Attenuators!
Some times a result can be a surprise --- the simplest test was alternator ripple I used the cheap and cheerful Owon VDS1022I
I offer no explanation but they are identical --- might be different with a fast 12 bit Pico

Channel 1 Red with x20 Attenuator
Channel 2 Yellow plain jane 1:1 test lead


" Welcome to the 21st"


Attachments:
Last edit: 05 Aug 2019 08:05 by Andy.MacFadyen.
The following user(s) said Thank You: Noah

Please Log in or Create an account to join the conversation.

  • Wood
  • Topic Author
  • Offline
  • Junior Member
  • Junior Member
More
14 Aug 2019 14:23 #32814 by Wood
Replied by Wood on topic Attenuators!
This forum never ceases to amaze me. Thank you guys for the information and support. I never heard of owon before. I bought a u-scope to start out with and I've been looking at the hantek, but this owon looks like it might be a good starter scope as well. I noticed the max voltage on the owon is 400 volts. How exactly does the ratio work for an attenuator? A 20:1 will protect your device at 20 times the amount of rated voltage? So max input voltage is 400...with a 20:1 attenuator you're protected up to 8,000 volts (400×20)?
The following user(s) said Thank You: Tyler

Please Log in or Create an account to join the conversation.

  • Andy.MacFadyen
  • Andy.MacFadyen's Avatar
  • Away
  • Moderator
  • Moderator
More
15 Aug 2019 04:15 #32828 by Andy.MacFadyen
Replied by Andy.MacFadyen on topic Attenuators!
400v is the isolation voltage that is the voltage the scope can experience without zapping your PC. With a a 1x probe you can have a 50v dc screen I checked this by measuring the peak voltage put out by 24v booster battery charger which puts out a whacking 42v peak !!!! I am pretty sure the scope would survive direct to a normal gasoline fuel.injector but I would want an attenuator for a coil primary or diesel. Injector or piezo injector.

" Welcome to the 21st"


Please Log in or Create an account to join the conversation.

  • Not Allowed: to create new topic.
  • Not Allowed: to reply.
  • Not Allowed: to add attachements.
  • Not Allowed: to edit your message.
Time to create page: 0.636 seconds