I've done "Low-Z" probes like this many times. Works a treat, and with the tiny coax connectors used in cell-phones, you can design in reliable test points with a 500ohm resistor and a sub-micro-connector. 3-4 inches of wire-wrap wire twisted into a pair also makes a decent solder-on test point to tape to a scope probe tip.
The proto board was a good move. Even if you'd used leaded solder for a stronger joint, it's very easy to tear the metal coating off the resistor chip.
Is it be possible to use a super short piece of bare copper wire with just enough to clip the probe onto? Or would that have some kind of negative effect..
if you are talking about the normal osciloscope probe, no negative effect, it works better but is more harder to tip the signal on the PCB, also the osc. probe have an accesory that looks like a spring, this is designed to make contact on a ring on the probe (this ring is ground) and with this combination you can make a super short signal tip without worry the negative effects of large ground clip
Are there any DIY passive probes that work for 1MOhm? My scope has only 1MOhm. I tried a few and they have horrible ringing/reflections/whatever is going on.
I'm curious. Since your working with passive components. Would resistive soldering have a stronger solder joint. (Active components such as transistors or diodes might perceive a load and simply be destroyed)
7:14 Looks to me like you have the probe connected to the 16u2 XTAL1 connection, which is the input of the inverter that implements the oscillator. In general, to examine the oscillator is functioning, the XTAL2 pin, the inverter output, is a better bet as it's lower impedance. XTAL1, being an input, is a high-impedance terminal, with DC operating point set by resistor feedback internal to the chip. If the probe adds a significant DC path to ground, (as through 1k of probe + 50 ohm scope input), that will override the DC operating point, and set it to a low voltage at which the inverter can't oscillate with the amount of feedback provided through the crystal-capacitor feedback filter. So, this indeed demonstrates that attaching a probe to a circuit may disrupt the operation of that circuit. However, this DC disruption is rather mundane and avoidable (put a capacitor in series). Of more concern are the subtle ways that a probe can disrupt the _ac_ operation of the circuit -- attenuating the ac signal, delaying or slowing edges, adding ringing, and so on.
We have had a "ticket" open with Google/RUclips to try to figure out issues with comments. . . not sure why yours (and sometimes our hosts') comments randomly don't appear. . . .
@@element14presents Thanks for replying and explaining. You Tube lets me see my comment history and I found that showed when mine vanished. I'll now have a go at saying what I did originally, although its probably not profound enough to justify all this. Compare with the thingiverse 3D print "PCB Workstation with Nano-Probes by giufini"
Congratulations for your 50th video! Looking forward to the next 50 ! Great job!
I've done "Low-Z" probes like this many times. Works a treat, and with the tiny coax connectors used in cell-phones, you can design in reliable test points with a 500ohm resistor and a sub-micro-connector. 3-4 inches of wire-wrap wire twisted into a pair also makes a decent solder-on test point to tape to a scope probe tip.
Great video.
thank you so much for video
The proto board was a good move. Even if you'd used leaded solder for a stronger joint, it's very easy to tear the metal coating off the resistor chip.
Hello brother, very good video teach electronic.
Is it be possible to use a super short piece of bare copper wire with just enough to clip the probe onto? Or would that have some kind of negative effect..
if you are talking about the normal osciloscope probe, no negative effect, it works better but is more harder to tip the signal on the PCB, also the osc. probe have an accesory that looks like a spring, this is designed to make contact on a ring on the probe (this ring is ground) and with this combination you can make a super short signal tip without worry the negative effects of large ground clip
did you try the active probe on the end of that wire at 6:14
No. There isn't a good way to attach the active probe without a bunch of extra accessories, which would ruin the comparison.
Are there any DIY passive probes that work for 1MOhm? My scope has only 1MOhm. I tried a few and they have horrible ringing/reflections/whatever is going on.
Might have luck tearing apart some $30 china-special probes to solder down?
You can buy a 'through terminator' - a BNC through-connector that includes 50R termination. This will turn any 1M scope input into 50R.
I'm curious. Since your working with passive components. Would resistive soldering have a stronger solder joint. (Active components such as transistors or diodes might perceive a load and simply be destroyed)
7:14 Looks to me like you have the probe connected to the 16u2 XTAL1 connection, which is the input of the inverter that implements the oscillator. In general, to examine the oscillator is functioning, the XTAL2 pin, the inverter output, is a better bet as it's lower impedance. XTAL1, being an input, is a high-impedance terminal, with DC operating point set by resistor feedback internal to the chip. If the probe adds a significant DC path to ground, (as through 1k of probe + 50 ohm scope input), that will override the DC operating point, and set it to a low voltage at which the inverter can't oscillate with the amount of feedback provided through the crystal-capacitor feedback filter.
So, this indeed demonstrates that attaching a probe to a circuit may disrupt the operation of that circuit. However, this DC disruption is rather mundane and avoidable (put a capacitor in series). Of more concern are the subtle ways that a probe can disrupt the _ac_ operation of the circuit -- attenuating the ac signal, delaying or slowing edges, adding ringing, and so on.
any alternatives for 5mOhm scopes :O ?
What is a 5 milliohm scope?
oh my scope says that all the inputs are 1Mohm, and it has no 50Ohm inputs!@@bald_engineer
@@ameliabuns4058There are 50 ohm termination adapters available. Rigol (and others) sell them.
Great video!
$2k for the RT-ZS10 alone… holy cow!
I consider switching from Electronics to Lego, its the cheaper Hobby!
moooore technical please
I don't get how you knew the overshoot was in the probe and not in MCU
why don't my comments appear
We have had a "ticket" open with Google/RUclips to try to figure out issues with comments. . . not sure why yours (and sometimes our hosts') comments randomly don't appear. . . .
@@element14presents Thanks for replying and explaining. You Tube lets me see my comment history and I found that showed when mine vanished. I'll now have a go at saying what I did originally, although its probably not profound enough to justify all this. Compare with the thingiverse 3D print "PCB Workstation with Nano-Probes by giufini"
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