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Can Relays be used to switch nA currents?

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fala

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Hello, In many relays datasheet there is a parameter called "min permissible load" what exactly this parameter means? what happens if a relay that has a 1mV min permissible load be used to switch one nA current at low speed(1 switch every 10 minutes)?
Thank you
 

Gold plated contact relays can be used for low current applications
 

Hello Rauol, Thanks but what "min permissible load" means? some relays even with gold contacts have min permissible load about 0.1mA, so does it mean that they can't switch 1nA? e.g. **broken link removed**
 

yes .... its a good conductor like any other metal wire....if 1nA is the case then resistance hardly matters cos ur getting it due to high resistance in series.....
 

The problem is not the conductivity of the switch inside the relay but the leckage currents because of the isolation material!
Switching nA or pA with relays should be avoided. Unless there are special teflon or glass insulated relays. Also dirt on insulation (moisture and dust) could hurt a lot.
 

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    fala

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Switching very small currents with relays is not a good idea ..
The smaller the relay, the more it is likely to have a minimum load requirement because of contact material and surface area contact ..
Each relay has a wiping current it must exceed to work properly ..

Regards,
IanP
 

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    fala

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You need to use low leakage shielded relays , these are the types used by major test equipment manfacturers like teradyne etc. in there automatic test eqipment.
you can expect less than 0.3 pf inter contact capacitance and the bodies of the relays.
the contacts and the coils are shielded. needless to say these relays are expensive.
www.cotorelay.com
 

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    fala

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