<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">
<font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font><div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">On Oct 22, 2008, at 4:26 PM, Keith Nagel wrote:</span></font></div><blockquote type="cite"><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">So what else can we use? Yea olde magnetic pickup. I'm imagining</span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">something like a speaker cone arrangement. </span></font></div></blockquote><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">How about a plain old variable gap capacitor? </span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">If you use mechanical energy to pull apart two plates having a charge then work is done and the voltage necessarily rises. You can now discharge the plates through a circuit to obtain the electrical energy. All you need in addition is a trickle charge to maintain the average charge on the plates and full wave rectification. </span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"> D1 V1</span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">P---|>|---R1--o-------C2--o---B1--------Load</span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">| | | |</span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">G Mech.==>C1 G G</span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"> | </span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"> G </span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"> Fig 1 - Diagram of mechanically driven capacitor gap power supply</span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">In Fig. 1 a HV DC power supply P and D1 maintains a high voltage by trickle charge through on the plates of a variable gap capacitor C1, the gap of which is varied by mechanical power. The AC power from generated by the mechanically driven gap oscillations of C1 are transmitted through the DC current blocking capacitor C2 and a rectifying bridge B1 to the load.</span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">One advantage to this design is the RMS voltage V1 is only limited by the gap breakdown voltage, thus the advantage is avoiding in many cases problems obtaining sufficient voltage to effectively drive a bridge rectifier B1. If a sufficient voltage V1 is difficult to obtain, it is still possible to drive a FET bridge B1 (and diode D1 if necessary) using plate position sensing or potential sensing circuitry to drive the gates provided the energy required is not excessive. </span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br></span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">An alternative to power supply P plus D1 is to eliminate them and make at least one plate of the capacitor C1 a charged electret.</span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"> </span></font></div><div> <font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">Best regards,<br class="Apple-interchange-newline"></span></font><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br class="khtml-block-placeholder"></span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;">Horace Heffner</span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><a href="http://www.mtaonline.net/~hheffner/">http://www.mtaonline.net/~hheffner/</a></span></font></div><div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br class="khtml-block-placeholder"></span></font></div><font class="Apple-style-span" face="Courier" size="4"><span class="Apple-style-span" style="font-size: 14px;"><br class="Apple-interchange-newline"><br class="Apple-interchange-newline"></span></font> </div><br></body></html>