Ken Hewitt's Glo-Control Mk2 circuit and PCB

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" colspan=2 height=82 BGCOLOR="#006699" TEXT="#080000"> <div> <FONT SIZE="5" COLOR="#FFFFFF" FACE="Arial" ><B>JBVM Delemarre</B></FONT><B>     | </B><A HREF="id49.htm" TARGET="_top" TITLE="This is the English part of my home page"><U><B> Home</B></U></A></div> <div> <B>Ken Hewitt's Glo-Control Mk2 circuit and PCB </B>   |   <A HREF="id62.htm" TARGET="_top" TITLE="Ken Hewitts Glocontrol Mk2 circuit and P"><U>Ken Hewitt's Glo-control Mk2 circuit and PCB</U></A>   |   <A HREF="id63.htm" TARGET="_top" TITLE="Parts list GloControl Mk2"><U>Parts list Glo-Control Mk2</U></A>   |   <A HREF="id64.htm" TARGET="_top" TITLE="Photos of the GloControl Mk2"><U>Photo's of the Glo-Control Mk2</U></A></div> <div> </div> </td> </tr><tr> <td valign="top" width=210 BGCOLOR="#FFCC66" TEXT="#080000"> <div> <A HREF="http://www.welwyn.demon.co.uk/" TARGET="_top" TITLE="http://www.welwyn.demon.co.uk/"><U>Ken Hewitt</U></A>'s Glo-Control Mk2 driver for model airplane glow engines was presented in RCM&E in 1995. This circuit was build on strip-board. On these pages a printed circuit board for this driver is presented. This makes a solid piece of equipment to be used for everyday flying without any problems concerning the plug heating during starting of the model engine and without the worries on blowing out the element of the plug.</div> <bR> <div> <A HREF="id49.htm" TARGET="_top" TITLE="This is the English part of my home page"><U>Home</U></A></div> <bR> <div> <A HREF="id62.htm" TARGET="_top" TITLE="Ken Hewitts Glocontrol Mk2 circuit and P"><U>Glo-control Mk2 circuit and PCB</U></A></div> <bR> <div> <A HREF="id64.htm" TARGET="_top" TITLE="Photos of the GloControl Mk2"><U>Photo's of my Glo-control</U></A></div> <bR> <bR> <bR> <bR> </td> <td valign="top" height=398 BGCOLOR="#FFFFFF" TEXT="#080000"> <div> <I>Ken Hewitt's Glo-Control Mk2 circuit and PCB </I></div> <bR> <div> Glow drivers for model airplane engines are usually designed around some form of <B>current control or current stabilizing circuit</B>. When this current is adjustable for various types of glow plugs there is a good chance that the current that is applied for one plug destroys the next one when this is of a different type. During adjustment one has to keep a keen eye on the ampere meter (if and when present in the circuit) in order not to burn out the element of the plug.</div> <div> After some trouble with an old glow driver that kept on blowing out the plugs on my four stroke engines I decided that it was time for some improvement. And what an improvement is became to be!</div> <div> I remembered that some time ago I saw a design in <A HREF="http://www.modelflying.co.uk" TARGET="_top" TITLE="http://www.modelflying.co.uk"><U>RCM&E</U></A>, the English Radio Control Magazine, and after some searching through old issues I found the article that I was looking for in the July 1995 issue.</div> <div> Later on it proved that it could have been much easier. When I asked my meta searcher for the Web, Inforian Quest, to look for "glow drivers" is came up with the web version of the original article in RCM&E on <A HREF="http://www.welwyn.demon.co.uk/" TARGET="_top" TITLE="http://www.welwyn.demon.co.uk/"><U>Ken Hewitt's web site.</U></A></div> <div> This concerns a somewhat different approach in design as this is a <B>constant voltage driver.</B> The output voltage of the IC is kept constant at a value determined by a resistor divider composed by R1a/R1b and R2. The values of these resistors can be adjusted to make small changes in the output voltage. I provided for three voltages, 1.5, 1.7 and 1.9 volts, chosen by a special switch with a guard to prevent accidental change. (See the photo section)</div> <div> The main advantage of this design is that the voltage across the plug is kept constant and the current is automatically adjusted. I never blew up another plug since I use this driver!</div> <bR> <div> I made it in a self contained box together with some old NiCads (10 1100mAh cells) that provide current for at least ten afternoons of flying before they need a recharge! I am extremely satisfied with this glow driver!</div> <div> Because I don't like to build my electronics on strip board as suggested by Ken Hewitt in his article I designed a printed circuit board which is presented here as the subject of this page.</div> <div> I also made a copy of the electric scheme for your convenience if you want to build a driver for yourself, which I can highly recommend. All credits for the design of the circuit to <A HREF="http://www.welwyn.demon.co.uk/" TARGET="_top" TITLE="http://www.welwyn.demon.co.uk/"><U>Ken Hewitt</U></A>!</div> <bR> <div> The files to make the PCB print are now included in this web site. Goto the <A HREF="id65.htm" TARGET="_top" TITLE="Downloadable files"><U>download page</U></A> but read this part of the web site first.</div> <bR> <bR> <bR> </td> </tr></table></body>