On: Sun, 07 Apr 2002 19:14:07 -0500 Marylynn & Tony <[EMAIL PROTECTED]> Wrote:
Snip: > So, I still wonder >(beyond my competence to tell) whether this two-leads-used, one-dangling >approach is simply an incomplete wiring diagram.... Hi Tony; Three leads?, Is this a "Smart Fan" type with a speed sensor, or what exactly is it. You may have to do something with the third lead. If the correct two leads are connected properly that is. I did not know that the Umax machines took a three lead Fan. Although I have not had to be involved with the fans on my machine as yet. Wait til I get some power guzzling upgrades installed. If the third wire is a speed control, it may need to work between +5 and ground. Which would imply that one of the power leads must be at ground. This might mean that this Fan will not work strung between +12 and +5. However you could try tying the third wire either to the +12 through a 1K pullup resister or if that doesn't work tie it to +5 through a 1k pullup resister. This is if the fan is connected between +12 and + 5 v Power. If the fan is connected between +12 and ground then use the pullup resister connection to +5 or the pulldown resister connection to ground. I assume a Temp sensor turns a smart fan on when the Temperature rises above a set point and then off when cool enough. So one of the choices ought to meet the logic requirements for full on. This should be safe with a 1K resister to limit current when wrong. I don't know what type of device must be turned on to allow current to flow to the fan winding or whether it is current or voltage controlled. I am sure some of the more up to date people on the list can give more accurate information. I am just going on second guessing and supposition from what seems possible. Ernie -- SuperMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | Service & Replacement Parts [EMAIL PROTECTED] | & CDRWs on Sale! | SPECIAL SM LIST PRICES - 24x Bootable SCSI CDROM $39.99, Umax Processors $19.99 PowerSupplies from C500/C600 $49.99 J700/S900 $79.99 <mailto:[EMAIL PROTECTED]> Support Low End Mac <http://lowendmac.com/lists/support.html> SuperMacs list info: <http://lowendmac.com/supermacs/list.shtml> Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/supermacs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
