Hardware Scope Filter Photos

Picking up on a thread from the old Forum here are a couple of pictures of a home made noise filter for scopes like the Hantek that don't have built in filtering.

Picture on Google Photos Link

Web page with filter design

Try starting with a resistance of around 400 ohms and a capactance of 0.2 uF (0.2 micro Farads) this should be okay for cranking voltage compresion tests and alternator voltage ripple tests.

Wow, really like this Andy. Also thanks for posting those pictures AND the link to the calculator.
It would also be cool to see the difference of a same capture with and without this filter on your Hantek scope...

It was Tyler who found the circuit simulator link --- brilliant! great applet!

I don't use my Hantek much anymore as I find my battery powered Owon SDS Labscope much quicker and easier to use. The Owon has built in software filters but using a harware filter is quicker. I have some alternator voltage ripple caputures taken with the Owon with and without filter I will look them out and if I get time next week capture the same on the Hantek.

Denso 105Amp Alternator unnder about 40amp load at Idle Speed

Image 1 ---- No filter compared to <1kHz Low Pass Hardware Filter On Owon Scope



Image 2 --- <1kHz Low Pass Hardware Filter compared to <2kHz Low Pass Hardware Filter

Awesome! That's a pretty nice scope :woohoo:
Clear difference with the filters. The one without really looks like crap.
Sure post the captures from the Hantek if you find the time.

This is the Owon's built in software filter set <7 kHz low pass.

I had trouble getting the Hantek 1008 to do alternator voltage ripple as it lacks an AC setting so I used a capacitor to block the 12v DC.

Without filter --- better than expected




With filter

I had trouble getting the Hantek 1008 to do alternator voltage ripple as it lacks an AC setting so I used a capacitor to block the 12v DC.

Nice job!
Ok there's worse (without filter) but your work is definitely worth it. Thanks for sharing this Andy

Love the images, Andy! Noticeable difference between software and hardware filtering. Having looked at them side by side, I almost prefer the hardware filtering.

Honest question: How often do you measure AC ripple? I ask because I used to test for it daily, but don't much any more. Thoughts?