Good morning All About Circuits,
Experimenting with led flasher and sequencing circuits.
Have built several like the Velleman Wheel of Fortune
www.allenpitts.com\Wheel_of_Fortune_E_110126.gif
http://www.youtube.com/watch?v=leWdcgsAgo0&playnext=1&list=PLDFDFEB9C0AD9C49E
and the Chaney sequencer which is similar to
http://www.chaneyelectronicsstore.com/servlet/the-214/Sequential-LED-Flasher-Kit/Detail
http://www.allenpitts.com/electronics/555/4017-7.gif
and this forum's excellent
http://www.allaboutcircuits.com/vol_6/chpt_7/6.html
These are fun to look at but a draw back is that one must have special
knowledge (although it is only where the switch is and how to operater it)
for the viewer to see the effect. In a query to this forum Nerdegutta
suggested Mondotronics
http://www.jameco.com/Jameco/Products/ProdDS/358580.pdf
Modulated Infrared Reflective Detector (MIRD) Schematic:
http://www.allenpitts.com/electronics/555/Modulated_Infrared_Reflective_Detector.gif
as a means of activation with only the presence of the viewer
to activate the circuit.
So the challenge, before I spend my twenty bucks on the infrared
detector, is to figure out how to turn the LED sequencer circuits
on using the infrared detector.
The Wheel of Fortune takes a momentary switch as shown in the schematic is the GIF
listed above. I think it is a normally off momentary switch so I think
a pulse from a 555 timer acting in the monostable mode would get the
job done. True? Do momentary switches come in normally off and normally on types?
But that is more speculation since the project I am actually trying to
master is the ten LED sequencer shown at All About Circuits. The activating switch in the
http://www.allaboutcircuits.com/vol_6/chpt_7/6.html
at All About Circuits, the Chaney and the 4017-7 above would be a simple on off switch where
in the 4017 portion of the circuit that is connceted to the LEDs would be connected to the voltage continually and the voltage
connection to the 555 would be switched. In this case the 555 would be
operating in bistable mode and turning the 4017s on for a set period of time as the 555 goes between triggered and reset.
So I went looking for a circuit to operate the LED sequencer when I happily discovered that
there was already 555 activator in all of these the 4017 cicuits.
The most important question is about my understanding of 555s. I believe
the 555 in the 4017 circuits listed above is in bistable mode as in
http://www.allenpitts.com/electronics/555/tim42.gif
and the resistors R1 and R2 control how long the timer is off and how long it is on. True?
If all that is true the question is how to the MIRD (infrared detector)to turn on the 555 timer operating
in bistable mode whixh would then activate the
sequencer. In the MIRD schematic above
there is a 'Signal Out' node. Is the solution as simpla as connecting the
Signal Out on the MIRD to pin 2 (trigger) and pin 6 (threshold) of
the 555 timer?
Thanks.
Allen in Dallas
Experimenting with led flasher and sequencing circuits.
Have built several like the Velleman Wheel of Fortune
www.allenpitts.com\Wheel_of_Fortune_E_110126.gif
http://www.youtube.com/watch?v=leWdcgsAgo0&playnext=1&list=PLDFDFEB9C0AD9C49E
and the Chaney sequencer which is similar to
http://www.chaneyelectronicsstore.com/servlet/the-214/Sequential-LED-Flasher-Kit/Detail
http://www.allenpitts.com/electronics/555/4017-7.gif
and this forum's excellent
http://www.allaboutcircuits.com/vol_6/chpt_7/6.html
These are fun to look at but a draw back is that one must have special
knowledge (although it is only where the switch is and how to operater it)
for the viewer to see the effect. In a query to this forum Nerdegutta
suggested Mondotronics
http://www.jameco.com/Jameco/Products/ProdDS/358580.pdf
Modulated Infrared Reflective Detector (MIRD) Schematic:
http://www.allenpitts.com/electronics/555/Modulated_Infrared_Reflective_Detector.gif
as a means of activation with only the presence of the viewer
to activate the circuit.
So the challenge, before I spend my twenty bucks on the infrared
detector, is to figure out how to turn the LED sequencer circuits
on using the infrared detector.
The Wheel of Fortune takes a momentary switch as shown in the schematic is the GIF
listed above. I think it is a normally off momentary switch so I think
a pulse from a 555 timer acting in the monostable mode would get the
job done. True? Do momentary switches come in normally off and normally on types?
But that is more speculation since the project I am actually trying to
master is the ten LED sequencer shown at All About Circuits. The activating switch in the
http://www.allaboutcircuits.com/vol_6/chpt_7/6.html
at All About Circuits, the Chaney and the 4017-7 above would be a simple on off switch where
in the 4017 portion of the circuit that is connceted to the LEDs would be connected to the voltage continually and the voltage
connection to the 555 would be switched. In this case the 555 would be
operating in bistable mode and turning the 4017s on for a set period of time as the 555 goes between triggered and reset.
So I went looking for a circuit to operate the LED sequencer when I happily discovered that
there was already 555 activator in all of these the 4017 cicuits.
The most important question is about my understanding of 555s. I believe
the 555 in the 4017 circuits listed above is in bistable mode as in
http://www.allenpitts.com/electronics/555/tim42.gif
and the resistors R1 and R2 control how long the timer is off and how long it is on. True?
If all that is true the question is how to the MIRD (infrared detector)to turn on the 555 timer operating
in bistable mode whixh would then activate the
sequencer. In the MIRD schematic above
there is a 'Signal Out' node. Is the solution as simpla as connecting the
Signal Out on the MIRD to pin 2 (trigger) and pin 6 (threshold) of
the 555 timer?
Thanks.
Allen in Dallas
