3 ms·
Why would an oscilloscope probe ever draw more than a few mW or even microwatts? I'd expect a normal optoisolator module to work for a probe like that. No need
by dragontamer 3y ago
Why would an oscilloscope probe ever draw more than a few mW or even microwatts?
I'd expect a normal optoisolator module to work for a probe like that. No need for 180mA+ transferred between circuits.
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An oscillator probe is an example where electrical isolation + signal (aka: communications) are useful. But under no circumstances should 500mW of power be sent through such a setup in either direction.
- duskwuff 3y agoThe amplifiers in high-speed active probes can use nontrivial amounts of power. I don't have specific numbers as the probe/scope interfaces are proprietary, but I wouldn't be surprised if some of the wired (non-isolated) probes draw multiple watts. > I'd expect a normal optoisolator module to work for a probe like that. Absolutely not. "Standard" optoisolators tend to be slow and have analog characteristics which are unsuitable for an oscilloscope.
- quailfarmer 3y agoActive probes can draw several watts. Probably shouldn’t, but no one is optimizing them for efficiency
- dragontamer 3y agoIIRC, leaker and worse-power BJTs handle higher-power and have lower noise. (Though Google says JFETs have even lower noise). But the numbers discussed here is a lot more power than I was expecting. I'm guessing that at the GHz-range, everything uses more power though.