----- Original Message ----- From: "Charles M. Brown" <[EMAIL PROTECTED]> To: <vortex-l@eskimo.com> Sent: Thursday, March 08, 2007 5:47 AM Subject: Re: [Vo]: Proof of capturing ambient temperature energy
> On Wed, 7 Mar 2007 20:48:47 +0100 > "Michel Jullian" <[EMAIL PROTECTED]> wrote: >>To avoid the voltage drop associated with a diode, which >>is huge compared to the noise signal, one could use smart >>auto-controled switches (fets) instead, which would only >>connect the noise source to the capacitor when the source >>is at a higher potential than the capacitor. This kind of >>diodelesss rectification scheme is used in low voltage >>switchmode power supplies, and is called "synchronous >>rectification". >> >>A kind of "sample and hold" which would resample every >>time the noise signal gets higher than the storage >>voltage. >> >>Now would the whole system be able to power itself plus >>some excess in isothermal conditions, where the switches >>themselves exhibit thermal noise? That's the question. >> >>Michel >> > > Charlie's comment 1: > I think that gates and drains on one buss / sources on the > other buss FETs could substitute for diodes in an array. I think you mean "bus" ;-) No it wouldn't work this way, simulate this and you'll see what I mean, maybe we could all agree to use LTSpice so we can share simulations? > Johnson noise in the channels will be rectified as it > interacts with the gate. > This would be harder to fabricate even if the gate is a > metal mesh. Sampling and holding is not needed. "sample and hold" was an attempt to describe how a synchronous rectifier works: every value higher than the previously sampled value is "sampled and held" sort of. But "zero voltage drop rectification", which is the end result, is a much better description. Michel
