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Electronics => Beginners => Topic started by: lordvader88 on July 28, 2018, 07:57:40 am

Title: Keithley DMM cap's still charged after at least 2 weeks LOL
Post by: lordvader88 on July 28, 2018, 07:57:40 am

I ordered an older style bench DMM almost 2 weeks ago. It arrived today and I unboxed it and flicked all the buttons and some LED lit up for a moment. I wonder how long ago the seller plugged it in? Well at least 1 cap must be pretty good, and not have a bleeder resistor.

I never bothered powering it up yet, too late now, bed time.

Title: Re: Keithley DMM cap's still charged after at least 2 weeks LOL
Post by: HighVoltage on July 28, 2018, 08:13:00 am

What model is it ?
Some older Keithley instruments have batteries inside

Title: Re: Keithley DMM cap's still charged after at least 2 weeks LOL
Post by: lordvader88 on July 28, 2018, 08:22:33 am

Keithly 177

I forgot tho....there's no probes with it. I'll try some handheld DMM probes with it

Title: Re: Keithley DMM cap's still charged after at least 2 weeks LOL
Post by: Muxr on July 28, 2018, 05:31:11 pm

Maybe it flickered from the inductive power of a switch you were pressing.

Title: Re: Keithley DMM cap's still charged after at least 2 weeks LOL
Post by: ArthurDent on July 28, 2018, 09:40:59 pm

I'd say post #2 from HighVoltage has the correct answer. Check to see if the DMM is fitted with the 1788 battery option. Here is the link to the manual.

https://www.utwente.nl/en/tnw/slt/documentation/Equipment/GeneralEquipment/keithley177.pdf (https://www.utwente.nl/en/tnw/slt/documentation/Equipment/GeneralEquipment/keithley177.pdf)