niconiconi on Nostr: Yesterday I've just found out the hard way that even a 10 GΩ voltmeter is still not ...
Yesterday I've just found out the hard way that even a 10 GΩ voltmeter is still not enough for experimenting with small capacitors. 10 GΩ is DCR only. As soon as you connect the voltmeter to a capacitor, it's immediately discharged by front-end input capacitance of the voltmeter itself (around ~100 pF?). But I wonder if I can make a "electrometer for the poor" using classic 50+450 Ω oscilloscope probe trick here to create a 100x probe on steroids with 1000+10 GΩ impedance. Just ordered a 1 TΩ resistor... Let's see how it goes...
Published at
2024-06-22 14:55:10Event JSON
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"content": "Yesterday I've just found out the hard way that even a 10 GΩ voltmeter is still not enough for experimenting with small capacitors. 10 GΩ is DCR only. As soon as you connect the voltmeter to a capacitor, it's immediately discharged by front-end input capacitance of the voltmeter itself (around ~100 pF?). But I wonder if I can make a \"electrometer for the poor\" using classic 50+450 Ω oscilloscope probe trick here to create a 100x probe on steroids with 1000+10 GΩ impedance. Just ordered a 1 TΩ resistor... Let's see how it goes...",
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