EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: hussamaldean on December 09, 2018, 02:00:17 pm
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Hi all,
I got this crazy idea while I was in the shower (the best place to think though :-DD :-DD) is that why not using relay for input protection in the current range of the multimeter which will not be active unless the current range is selected and the probe in the right place!!
I think this idea will increase the safety level of the current range or just crazy idea I have like other ideas which leads always to a catastrophe :D
regards
looking forward to ur answers :D
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relays are too slow
some analog meters has two diodes across shunt to protect meter
diodes actually limits voltage drop below 0.6V
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Your typical Fluke 87V would need a 1000V relay, capable of 10 Amps, and breaking capacity for CAT IV, with a consistent contact resistance.
Those are very specific. Economically not very feasible.
Instead, just use the operator as relay, wiring it correctly. Or use the simple technology from Gossen Metrawatt, only exposing the terminals for the configuration the meter is currently in.
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What about current consumption?
The Siglent bench multimeter do this, it will automatic change to higher range when a current range is overloaded, also if manual range is selected. I doubt it works if you are in AC current and apply DC current or vice versa.
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What about current consumption?
The Siglent bench multimeter do this, it will automatic change to higher range when a current range is overloaded, also if manual range is selected. I doubt it works if you are in AC current and apply DC current or vice versa.
It's only switching the measurement pick-off point from the shunts for different range resolution.