Re: Reg MKII's and cooling fans.

["Joe Smalley" <joes@worldfront.com>]

> C) Figure out if I can easily make SOMETHING that would let me hook them
up
> to the MKII (Internal Load) regs so they come on when the reg starts
> dissipating heat.  There are external load connectors on the reg, but I
> don't know if hooking up one of these little fans to them would cause a
> problem.

If you hook the positive terminal of the fan up to U1-Pin 7, the fan will
come on when the green LED comes on. There is only 40 milliamps available
from this pin. If you draw more current that this, the reg won't turn on. If
your fan needs more than 40 milliamps of inrush current, you can use an
emitter follower to increase the current available to the fan. Use an NPN
bipolar transistor and connect the collector to J2 (BAT+), the base to
U1-pin 7, the emitter to the positive terminal of the fan and the negative
terminal of the fan to J6 (BAT-). If you use a large enough transistor, this
circuit will run any 12 or 15 volt muffin fan.

Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
joes@worldfront.com