Re: 68HC11


The zero crossing circuit uses 12VAC running thru a phototransistor
CNY17-3 with a 54K resistor and a 1N4007 across pin 1 and 2 of the
CNY17-3, the other side of the CNY17-3 is connected with a series of
capacitors and resistors coupled w/ a BC547 NPN transistor where the
output from the zero crossing is tapped from the collector of the
BC547.

The dimmer circuit was constructed relatively easily since i just
followed the application notes on the optocoupler MOC3021 and used a
triac SC140, the control of the dimmer would come from Pin1 of the opto
since i've previously tested by running an output from a full bridge
rectifier connected to an LM741 generating a simulated zero crossing
however with a variable resistor acting a manual dimmer.

I understand the 68HC11 is a relatively simple MCU however, being out
of school quite a while already and trying to understand it still gives
me the headaches.




------

Joe Pfeiffer wrote:
"Xronocruz" <crimsoncolours@xxxxxxxxx> writes:

hi there,
im not too sure if this is the right place to ask for help for 68HC11
but i would like to ask if anyone knows how to program the PortA of the
68HC11 so tat it is able to take in inputs from a zero crossing circuit
and then be able to control a dimmer circuit?
would appreciate any help rendered..
many thanks.

So... what does the input from the zero-crossing circuit look like?
What does the output to the dimmer circuit look like? An HC11 is
really easy to program, but you sort of have to know what the hardware
is first....
--
Joseph J. Pfeiffer, Jr., Ph.D. Phone -- (505) 646-1605
Department of Computer Science FAX -- (505) 646-1002
New Mexico State University http://www.cs.nmsu.edu/~pfeiffer

.

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