Doug Ford shows us how he designed his own 1000:1 high voltage oscilloscope probe.
http://www.dfad.com.au
and the Oscilloscope probe tutorial:
http://dfad.com.au/links/THE%20SECRET%20WORLD%20OF%20PROBES%20OCt09.pdf
http://www.dfad.com.au
and the Oscilloscope probe tutorial:
http://dfad.com.au/links/THE%20SECRET%20WORLD%20OF%20PROBES%20OCt09.pdf
Hi, thanks a lot for your video. In order to check the wave of an inverter or mains, is it ok to use a step down transformer 240/24 ? Will it smooth or disturb the 50/60Hz signal ? What about armonics ? Thanks.
Question please…. When you connect your scope probe, do you set it for x1 or x10???? the resulting multiplier would also be selected in the scope, (the 1000x option) I have a small bunch of 1000Mohm 10 KV 1 watt resistors and if I was mostly using for DC voltages, could placing one of these in series with the scope probe and with the scopes impedance being ~1 Mohm, would this provide satisfactory readings with the scope probe set to x1 and the 1000Mohms would be very roughly a 1000 to 1 ratio??? I did try this for my DVM with 2 1000Mohm 10KV 1 watt resistors in series and this worked out to about a 200 to 1 ratio since my Fluke has a typical-measured, 10 Mohm internal resistance and my reading were very close to what was expected, (the Fluke is considered to be a x1 device)…. It would not be elegant, but do you think a similar hook up for my scope would suffice?? Thanks for any explanations you may provide…. Hank
nice
Awsome vid…..ur links dont work
But can we hold the probe in our hands while measuring? Only copper there doesn't feel it's isolated. How should we isolate it? Normal plastic would do? Or it wouldn't be enough?
The birds have to sing for their supper.
Who are you and what have you done with Dave ?….lol
Hey Dave, this is excellent! I'm not much of an electronics guy, mostly mechanical, but I do need to do an increasing number of electronics projects these days. So I was wondering if you have an EEVblog # that deals with how to Protect a Probe from a voltage spike? Thing is, I made a make-shift probe for probing vehicle secondary ignition signals, and if the coil or wire has leaks, a 30kv spark will jump into the probe tip and fry the scope. It's an inductive pickup of sorts, so it's not designed for direct electricity. So I was wondering how to make some kind of shunt or protection for those sparks. Got a blog on doing that? Thanx!
For divide by 1000, you should consider two divide by 32 stages. Also, you can provide an inner shield connected to the probe if your HV has low impedance; this increases input capacitance, but maintains your HF response.
Dear sir
I have a Philips pm 3200 0 – 10 MHz osiloscoop but i dont have the PROBES can you pls help me out with the chematic of the probes . Kinds regards
that sparrow make me mad 😒
YEP!!!
Thank you very much for this video
I just found that old video and immediately recognized the voice. Hey it's the microphone guy!
Just checking my Favorites list, saw this one down the bottom of the list. Salutations from the year 2018.
Whoa, Dave. This one's pretty old.
We would have liked seeing it tested.
The red cable is a high voltage cable? Does it have a ground wire?
what happens if you put two 10:1 attenuators in series? does it make it 20:1?
????
10 puff?
Cool,but good probes use coax with a resistive center conductor to reduce ringing when used with a high impedance scope input.A resistive conductor distributes the total resistance (usually around 100-200 ohms) over its length.A lumped (discrete) resistor on the end of a piece of regular coax will not noticeably reduce ringing.Also a hi-Z probe should be well shielded and then there is the 'high voltage' issue….
Great idea and all but, with all the respect, half of the speech I did not understand, could you tell me please what is that "tail wire" for? and how this unit is attached to the oscilloscope and the probe? I just got part of the description… Thanks in advance.
I'm interested by the cal factor. What does this represent exactly? Is it the ratio of input to output voltage?
I assume that you'll be attaching your probe to an oscilloscope, which will have 10-15pF capacitor and a 1M ohm resistor within that scope. It looks like you've omitted that out of your design, which also might be a reason why the cal factor alters at 200Hz.