mmm@weitek.UUCP (Mark Thorson) (10/22/85)
Matt Crawford writes: > Device #1: an electrical device which takes in 10 volts AC at 1 ampere > and puts out 100 volts AC at 1 ampere. The device will not > contain any internal energy sources and the measurements of > current and voltage will not be faked. I give up. Someone said this is a transformer, but that would step down current while stepping up voltage. Maybe the whole net is smarter than me, but I haven't seen any net explanation of this one. Nor has anyone questioned whether this is possible. I must be missing something. Is the current flow continuous? Thank goodness I work in digital :-) Mark "I'm curious, but not $1000 curious" Thorson (...!cae780!weitek!mmm)
js2j@mhuxt.UUCP (sonntag) (10/25/85)
> Matt Crawford writes: > > Device #1: an electrical device which takes in 10 volts AC at 1 ampere > > and puts out 100 volts AC at 1 ampere. The device will not > > contain any internal energy sources and the measurements of > > current and voltage will not be faked. > I give up. Someone said this is a transformer, but that would step down > current while stepping up voltage. Maybe the whole net is smarter than me, > but I haven't seen any net explanation of this one. Nor has anyone questioned > whether this is possible. I must be missing something. Is the current flow > continuous? Thank goodness I work in digital :-) > > Mark "I'm curious, but not $1000 curious" Thorson (...!cae780!weitek!mmm) Instantaneous power supplied through a set of terminals is given by voltage(t) * current(t). Work out the formula for the average power with sinusoidal voltages and currents of the same frequency and a constant phase shift, and you'll find that the power is: P = Vrms * Irms * cosine(phase difference) Note that if the phase difference is 90 degrees, or very close to it, very little power can be used in producing large voltages and currents. This can be done by using a large value inductor as a load. Thank goodness you work in digital. :-) -- Jeff Sonntag ihnp4!mhuxt!js2j "Now, I don't believe in doing anything half-way, or in watered-down versions of ANYTHING." - Ted Holden, noted Veliskovskian.