Take all the JUNK out, use a PNP power transistor driven by the control
signal.
(Your 2N222 connection is nonsense.)
Emitter to +3.3 V.
Base is the drive signal.
Collector goes to the LEDs.

Dave King wrote:

>> Alternatively put a gif up on a web site somewhere or send it to me
>> direct
>> & I'll have a quick look.
>
>
> I've put the information up on the backend of my website
> at  http://members.shaw.ca/gnat/led.htm
> That has the schematic for the problem section and a image of the scope
> signals.
>
>> If you are using MOSFETS you will need more than 3.3V on the gate to
>> turn
>> them on properly. If you have only this voltage to play with you will
>> need
>> to change to a bipolar power transistor or arrange a higher voltage gate
>> drive supply using a charge pump/aux supply or whatever. It would
>> only need
>> a mA or so depending on switching rate.
>>
>> Richard
>
>
> Ok I'll dig out my books and get on the net and start looking for a
> bipolar. It does need
> to be able to handle about 1.7A at a 20% duty cycle. I'm almost stuck on
> having to deal with
> 3.3 as my main supply voltage as going up to 5 will do a number on the
> cost
> of things.It could
> be done but I'd rather shy away from doing that unless I have to.
>
> I really appreciate any and all help on this. I haven't had to play with
> transistors for quite a few years
> so I'm out of touch with what works in the 3.3v regime and what won't.
>
> Cheers
>
> Dave
>
> --
> http://www.piclist.com hint: The PICList is archived three different
> ways.  See http://www.piclist.com/#archives for details.
>
>
>

--
  *
  |  __O    Thomas C. Sefranek  tcs@cmcorp.com
  |_-\<,_   Amateur Radio Operator: WA1RHP
  (*)/ (*)  Bicycle mobile on 145.41, 448.625 MHz

ARRL Instructor, Technical Specialist, VE Contact.
http://hamradio.cmcorp.com/inventory/Inventory.html
http://www.harvardrepeater.org

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body