OK,
hopefully someone from OZ can help me here.
I'm looking for a logic level MOSFET, or HEXFET, etc which is easily available in Australia (read from Jaycar, Tandy, Dick Smith or Dontronics) Small orders being no problem.
I typically will need it to be logically switched off normal TTL levels and I'll need it to switch 9-15V at several amps (2-5 for .25 of second).
Can someone direct me with part numbers of suitable components?

many many thanks,
Des Bromilow


  Use a "logic" MOSFET (turns on at about 3V on the gate) for this job.
If you want cheap, use a PNP transistor with emitter to 5V, collector to
relay to ground and base to logic gate via a resistor of about 10k.

  A corresponding logic FET would be a P-channel one, which are not as
readily available and therefore probably not as cheap.  With the FET
however, you do not need a resistor; the FET gate connects directly to
the CMOS output.

  For either FET or transistor, you need the diode across the relay in
the direction it doesn't conduct when the coil is energised by the
transistor.

  For any further suggestions, please specify the relay coil resistance.
--
  Cheers,
        Paul B.