On Thu, 19 Nov 2009 13:02:30 -0600, John Fields wrote: >On Thu, 19 Nov 2009 18:53:02 +0100, "Arie de Muynck" >wrote: > >>John Fields ... >>> Ian Jackson ... >>>>Is that really a 5 microamp meter, or actually just a meter with a 5 >>>>microamp FSD scale? >>> It's real. :-) >> >>And a real beauty it is. >> >>What is the internal resistance, > >--- >Can't find the spec but, measured here, about 6000 ohms. >--- > >>AKA how much uWatt does it need? > >--- >Since P = IČR = 5e-6A * 6e3R = 3e-2W = 30mW for full-scale deflection. >--- > >>And how does that compare against 'normal' instruments? > >--- >Dunno, but check out the Simpson, Tripplett, etc. websites to find out. >--- That is pretty typical of the sensitive movements that i have been close enough to touch. A hand full or so, not all that many. Then again, they never were all that common. > >>I noticed that e.g. the same type of relay always need the same coil power >>regardless the voltage. > >--- >OK... > >JF