<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div id="yui_3_16_0_1_1434407794592_42385"><span>Pete,</span></div><div id="yui_3_16_0_1_1434407794592_42629"><br><span></span></div><div dir="ltr" id="yui_3_16_0_1_1434407794592_42630"><span id="yui_3_16_0_1_1434407794592_42939">I thought that your explanation was quite accurate. Especially since I used to cut trees as a young man. Now that I know the application is just a simple education lesson, as long as the motor is small, the MOSFET is probably the best fit. I would use a MOSFET with an integrated diode. Impossible to get it the wrong way. However, optical isolators also allow you to drive MOSFETs at higher voltages. Even the logic level MOSFETs can be driven much stronger than 5v and in most cases what is considered a logic level MOSFET is really just a MOSFET that allows some current to flow at 5v, but does not even come close to the full potential. The optical isolator can completely separate the voltages and eliminate all noise. This is my favorite way to solve this problem, simply because the noise on the motor side electronics can be tolerated quite well by the driving chips in most cases.</span></div><div id="yui_3_16_0_1_1434407794592_44238" dir="ltr"><br><span id="yui_3_16_0_1_1434407794592_42939"></span></div><div id="yui_3_16_0_1_1434407794592_44578" dir="ltr"><span style="" class="" id="yui_3_16_0_1_1434407794592_42939">Did I say MOSFET enough. No? </span><span style="" class="" id="yui_3_16_0_1_1434407794592_42939"></span></div><div id="yui_3_16_0_1_1434407794592_44739" dir="ltr"><span style="" class="" id="yui_3_16_0_1_1434407794592_42939"><br></span></div><div id="yui_3_16_0_1_1434407794592_44737" dir="ltr"><span style="" class="" id="yui_3_16_0_1_1434407794592_42939">MOSFET</span><span style="" class="" id="yui_3_16_0_1_1434407794592_42939">, MOSFET</span><span style="" class="" id="yui_3_16_0_1_1434407794592_42939">, MOSFET</span><span style="" class="" id="yui_3_16_0_1_1434407794592_42939">, MOSFET</span></div><div id="yui_3_16_0_1_1434407794592_44736" dir="ltr"><br><span style="" class="" id="yui_3_16_0_1_1434407794592_42939"></span></div><div id="yui_3_16_0_1_1434407794592_44738" dir="ltr"><span style="" class="" id="yui_3_16_0_1_1434407794592_42939">Just in case you weren't sick of it yet.</span></div><div dir="ltr"><span style="" class="" id="yui_3_16_0_1_1434407794592_42939"><br></span></div><div dir="ltr"><span style="" class="" id="yui_3_16_0_1_1434407794592_42939">John Vaughters<br></span></div> <div style="" class="" dir="ltr"><span style="" class="" id="yui_3_16_0_1_1434407794592_42939"> </span></div><br><div id="yui_3_16_0_1_1434407794592_44765" class="qtdSeparateBR"><br><br></div><div style="display: block;" id="yui_3_16_0_1_1434407794592_44956" class="yahoo_quoted"> <div id="yui_3_16_0_1_1434407794592_44955" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px;"> <div id="yui_3_16_0_1_1434407794592_44954" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1434407794592_44953" dir="ltr"> <font id="yui_3_16_0_1_1434407794592_44965" face="Arial" size="2"> On Monday, June 15, 2015 7:27 PM, Pete Soper via TriEmbed <triembed@triembed.org> wrote:<br> </font> </div> <br><br> <div id="yui_3_16_0_1_1434407794592_45175" class="y_msg_container">OK, this came across very pedantic. Sorry, Brian! There have got to be <br clear="none">better analogies out there, and I've now established the benchmark for <br clear="none">crap in this regard.<br clear="none"><br clear="none">-Pete<br clear="none"><br><br></div> </div> </div> </div></div></body></html>