Re: [volt-nuts] Cropico DO4A Digital Ohmmeter

You didn't mention the power rating of these resistors.  Do they have a brand name?  They are likely wire wound; how much inductance, self resonant frequency? I could use them for various purposes depending on the answers to the above. The thing that makes me curious is that your 'average' is

Re: [volt-nuts] Cropico DO4A Digital Ohmmeter

Fractional and even Ohm resistors- Once, in a package from Russia, with some items totally not related to this group discussion, the seller included 2 boxes of 1/2% 200 ohm resistors with a note of thanks for the purchase. Each box contained several cardboard carriers with 25 resistors lined up

Re: [volt-nuts] Cropico DO4A Digital Ohmmeter

I have a few very low resistance resistors (around 50 milliohms), four terminal of course, rated at .05% or maybe better.  I built a low resistance Ohmmeter but don't use it since I got my HP3456A with very good resolution.  I can measure the resistance of a screwdriver shaft with it, although

Re: [volt-nuts] Cropico DO4A Digital Ohmmeter

On 29 April 2018 at 21:57, Nigel Clarke via volt-nuts wrote: > > Sorry, I realise now I could have explained better, I do know what > transistor it is but that's not the problem, this looks to be quite a > complex power suply/charger circuit, with at least three unmarked >

Re: [volt-nuts] Cropico DO4A Digital Ohmmeter

Sorry, I realise now I could have explained better, I do know what transistor it is but that's not the problem, this looks to be quite a complex power suply/charger circuit, with at least three unmarked adjustment pots so if I change the device, even for the same part number, it's quite

Re: [volt-nuts] Cropico DO4A Digital Ohmmeter

Or expose enough leads of the damaged parts to check what it is and find a replacement. If it's on the heatsink, it is probably used as a linear regulator and there will be a large section of the datasheet that you can safely ignore. On Sun, Apr 29, 2018, 7:02 AM Nigel Clarke via volt-nuts

[volt-nuts] Cropico DO4A Digital Ohmmeter

Perhaps somewhat off topic but just wondering if anybody here would have a service manual for this instrument, or even just a schematic particularly of the power supply section? I've just bought one that was totally dead on arrival and it looks to have been blessed by the idiot's touch, both