This page is for people who have some kind of mechanical device such as
a spinner already built and want to add the electronics to connect it
to the Opti-Pac Plus. Only the electrical connections are covered here,
you'll still have to work out a method of mounting the sensors or PCB
to your mechanical device and you will need a spoked disk mounted on
the shaft. Two methods are covered: Using a Happ Controls Optical PCB
and Using a pair of Opto Switches.
Happ Optical PCB.
This is what the PCB looks like and shows the connections. Simply wire
up each pin as shown on the picture to the corresponding connection on
This method uses a pair of standard opto-switches. These can be
obtained from electronics supply stores. The cheapest type will do,
which simply have a LED in one side and a photo-transistor on the
other. They usually cost less than $1.
In the US try Digi-Key. An example part number is QVB11334. You will
also need a 220R resistor.
The switches will be marked "E" and "S" on each side. the "E"
side=Emitter and "S"="Sensor" (may also be "D"=Detector). First glue
the sensors together with the "E" marks alongside each other as shown
below: Then turn over the assembly. IMPORTANT: The pictures below show
the assembly with the "E" sides at the TOP.
Solder a 220R resistor as shown between the two diagonally opposite
pins on the right-hand sensor. Solder the lower left pin of the
right-hand sensor to the lower left-hand pin on the left-hand sensor
(bend the pin around).
Solder the top left pin of the right sensor to the top right pin of the
left sensor. (Hopefully the picture is easier to understand than this
description!). Cut off any protruding pins of these two you just
You should end up with four protruding pins left. Connect these to the
Opti-Pac Plus. The picture shows push-on connectors but you could just
solder wires to each of the four pins. Some shrink-fit sleeving
finishes off the job. For this configuration the jumpers are set to
"A/LO" on the Opti-Pac.
Now mount the assembly on your mechanics by whatever method works. The
optical wheel should be positioned centrally in the notch of the