Price - Stock No 250 - Fast
Price - Stock No 251 - Slow
Price - Stock No 252 - Variable
Superceeded Version - prior January 2007
Check your kit
- Make a visual check of the PC board for damage in transit. Look for
small breaks and/or other damage to tracks. The copper
tracks will have a green coating on the tracks. This
coating should be left in place as it protects the tracks from oxidation or
corrosion, and it does not inhibit
soldering in any way. A multi-meter or Electronic Circuit Tester can be
used to test continuity of the tracks.
- Mounting the components is relatively easy. The resistors will
have to have the legs bent to match their holes, and the greencap will fit in
easily - any way round.They can be soldered off as you go if you wish.
- The electrolytic capacitor is polarised, so look on the
body to find an arrow. This arrow points down the -ve (K) leg. Check the
drawing and put it in the right way round.
- To mount the push-button switch, push the two circuit board pins
into the holes where the switch goes. Solder them and then push
the legs of the switch down between the pins. Solder the switch to the
pins. This will give a solid mounting so the dice can be attached to its
box by the switch through a hole, with the nut on top.
The height of the flange of the switch will also give a height to
which the flanges of the LEDs can be adjusted before
soldering. The globe part of the LEDs will then push up through
your box and be supported in position by the switch. The
LEDs are also polarised. Find a small flat on the flange at
the base of the red dome. This flat is at the -ve(K)
leg. See the drawing for the correct
polarity of each LED.
- The 8 Pin & 16 Pin I.C. Sockets can be soldered in carefully to
make sure that no bridging occurrs between legs. You will find that the
legs of both the I.Cs are spread a little wide to fit into their
sockets. Take each I.C. and rest the legs on a
flat surface. Gently push down so that row
of legs is straightened a little. Repeat for the other row of
legs. Take the 555 Timer and find the locating mark on the top surface
and near or at one end. Check the drawing and push it into its socket
the right way round. The procedure for the 4017 is similar but ,
because it can easily be destroyed by static
electricity, leave it in its antistat case until you have all other
components, switches, battery snap etc. in place and soldered
off. Finally, find the locating mark on the top
surface of the 4017, check its position with the drawing,
and push the IC into its socket.
- The dice is now ready for testing. Connect a 9V
battery, switch the slide switch "on" and push the button.
All LEDs will light up; release the button and one will stay on. (
This is a purely random selection so there is no way to "rig" the
View the Datasheet for the 4017.
View the Datasheet for the 555.
If the dice doesn't work then you will need to check all
polarities and ensure that all components are in correct places.
Check soldering and resolder any suspect joints.
It will help if a general understanding of the circuit is acquired.
Briefly , when the PB switch is depressed a pulse is generated by
the 555 IC (Timer). This pulse is conducted to the 4017 IC
(Decade Counter) which acts as a rotary switch. In this case only six of
the IC's pins are used to distribute the
pulse to the LEDs in turn. The next pin in order is connected
to the reset pin of the IC. This restarts the switching action
to maintain an automatically resetting switching process. This all happens
very quickly, so fast that all LEDs appear to light up when the push button is
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