Author Topic: DIY Homebrew Oscilloscope Current Probe  (Read 5923 times)

0 Members and 2 Guests are viewing this topic.

Offline ZogTopic starter

  • Regular Contributor
  • *
  • Posts: 78
  • Country: au
  • Owning things means that things end up owning you.
DIY Homebrew Oscilloscope Current Probe
« on: May 20, 2018, 02:02:57 am »
I have heard mention that's it's possible to make an el'cheapo oscilloscope current probe from ferrite beads.

Anyone ever done this before ?

Or know where I can find information for it ?

I would like to make one for my Rigol DS1054Z
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 28368
  • Country: nz
  • Taupaki Technologies Ltd. Siglent Distributor NZ.
    • Taupaki Technologies Ltd.
Avid Rabid Hobbyist
Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 
The following users thanked this post: Zog, Johnny B Good

Offline CopperCone

  • Super Contributor
  • ***
  • Posts: 1415
  • Country: us
  • *knock knock*
Re: DIY Homebrew Oscilloscope Current Probe
« Reply #2 on: May 20, 2018, 03:22:43 am »
you can take a ferrite clamp put like 6 turns of wire around it and use that.

but unless you got a signal generator to kinda at least get an idea of the transfer function it might be difficult to use.
« Last Edit: May 20, 2018, 03:24:21 am by CopperCone »
 
The following users thanked this post: Zog

Offline ZogTopic starter

  • Regular Contributor
  • *
  • Posts: 78
  • Country: au
  • Owning things means that things end up owning you.
Re: DIY Homebrew Oscilloscope Current Probe
« Reply #3 on: May 20, 2018, 11:23:38 am »
thanks guys
 

Offline ocset

  • Super Contributor
  • ***
  • Posts: 1516
  • Country: 00
Re: DIY Homebrew Oscilloscope Current Probe
« Reply #4 on: May 20, 2018, 12:37:38 pm »
current probe: It depends what  current level, and what bandwidth you want, but current probes are generally not cheap.
Cheapo means sense resistors...or hall sensors if its higher current, or you can use current sense transformers   which are cheap if used certain ways in smps.
Eg as attached for current sense transformers in smps. Its an LTspice sim which is a free download
 

Offline ali_asadzadeh

  • Super Contributor
  • ***
  • Posts: 1904
  • Country: ca
Re: DIY Homebrew Oscilloscope Current Probe
« Reply #5 on: May 20, 2018, 12:59:50 pm »
Why not use Allegero current sensor chips, like the ACSxx series! some models can do till 1MHz with up to about 50A
ASiDesigner, Stands for Application specific intelligent devices
I'm a Digital Expert from 8-bits to 64-bits
 

Offline Doctorandus_P

  • Super Contributor
  • ***
  • Posts: 3356
  • Country: nl
Re: DIY Homebrew Oscilloscope Current Probe
« Reply #6 on: May 21, 2018, 07:05:43 am »
Are you thinking about a small probe for sniffing magnetic fields around a PCB trace, or for measuring high current stuff such as the other posts mentioned here?

AC or DC?
Bandwidth?
Accuracy?

The UNI-T UT210E is a nice clamp meter with an (Exceptional !!!) low current 2A DC range.
The Youtube guy who blows up all multimeters while "testing" them 4kV spikes once did a vid about this clamp meter.
He put in an opamp and connector and got about 2kHz bandwidth out of it.
The extra opamp is probably not needed, it's already got a low offset opamp near the current sensor.
 

Offline tautech

  • Super Contributor
  • ***
  • Posts: 28368
  • Country: nz
  • Taupaki Technologies Ltd. Siglent Distributor NZ.
    • Taupaki Technologies Ltd.
Re: DIY Homebrew Oscilloscope Current Probe
« Reply #7 on: May 21, 2018, 07:13:10 am »
The Youtube guy who blows up all multimeters while "testing" them 4kV spikes once did a vid about this clamp meter.
He put in an opamp and connector and got about 2kHz bandwidth out of it.
The extra opamp is probably not needed, it's already got a low offset opamp near the current sensor.
That YT guy is member Joe Smith and you can see all his DMM tests here:
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/
Avid Rabid Hobbyist
Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf