INFRA-RED DOOR ALARM

INSTRUCTION SHEET

 

Price - Stock No 245

 



 

 



 

 

Transmitter Construction

1. Check your P.C.Board carefully for damage to the tracks. A Circuit Tester or a multimeter will help check that there are no broken tracks.

2. Identify the resistors by their colour bands or with a multimeter - see Resistors. Bend the legs with long-nose pliers to match their holes and push them into place against the surface of the board. Remember that the drawing is looking at the PLAIN side with the tracks away from you. When in place, bend the legs sideways a bit to stop the resistors from falling out.   Solder in place - see Soldering Technique.

3. The 8 pin integrated circuit socket should be orientated with the 'notch' as shown in the placement diagrams.  Solder in place.

4. Identify the transistor legs with the above diagrams.  Orientate the transistor and when soldering take care to minimise the heat transferred to the transistor body.  A heat sink (or long nose pliers) clamped between the transistor body and the solder joint will minimise potential damage while soldering.

5. The electrolytic capacitor is polarised and care should be exercised to orientate it correctly.  Solder in place.

6. Two PCB pins are located at the switch connection points and two for connection of the 4 x AA battery holder.  Solder the pins in place. 

7. Identify the LED and the infra red LED.  They are polarised. There is a flat at the base of the globe. This is above the K leg, which is also the shorter leg. Put the flats as the drawing shows.  Solder in place.

8. Solder the switch to it's PCB pins.

9. Connect the battery holder with positive and negative as shown.

10.  Insert the PIC 12F675 which is pre-programmed with the transmitter program.  Take care to orientate this correctly.

11. Install the batteries and swith on.  You will see the LED rapidly flashing.

12. Turn off and set aside while constructing the receiver.


 

Receiver Construction

1. Check your P.C.Board carefully for damage to the tracks. A Circuit Tester or a multimeter will help check that there are no broken tracks.

2. Identify the resistors by their colour bands or with a multimeter - see Resistors. Bend the legs with long-nose pliers to match their holes and push them into place against the surface of the board. When in place, bend the legs sideways a bit to stop the resistors from falling out.   Solder in place - see Soldering Technique.

3. The 8 pin integrated circuit socket should be orientated with the 'notch' as shown in the placement diagrams.  Solder in place.

4. Identify the transistor legs with the above diagrams.  Orientate the transistor and when soldering take care to minimise the heat transferred to the transistor body.  A heat sink (or long nose pliers) clamped between the transistor body and the solder joint will minimise potential damage while soldering.

5. The electrolytic capacitor is polarised and care should be exercised to orientate it correctly.  Solder in place.

6. Two PCB pins are located at the switch connection points, two for connection of the 4 x AA battery holder and two for the buzzer.  Solder the pins in place. 

7. Insert the infra red receiver component as shown.  As with the transistor, care should be taken to minimise heat transfer while soldering.

8. Solder the switch to it's PCB pins.

9. Connect the battery holder with positive and negative as shown.

10.  Solder the buzzer leads to the PCB pins note positive and negative connection points.

11.  Insert the PIC 12F675 which is pre-programmed with the receiver program.  Take care to orientate this correctly.

12. Install the batteries and swith on.  You will hear the buzzer sound.

13. Turn off and follow the "Setting Up" procedure.

Setting up

  1. Arrange the transmitter and receiver about 1 metre apart with the IR LED of the transmitter pointing in the direction of the receiver
  2. Orientate the receiver so that the IR decoder is facing the transmitter.
  3. Turn the receiver ON - the buzzer will sound.
  4. Turn the transmitter on and the buzzer should stop.  If not check the orientation of both transmitter and receiver.
  5. If you place your hand (or some object) in the beam, the buzzer will sound.
  6. Increase the distance between the transmitter and receiver to suit your application - (maximum separation around 3m).

    Trouble shooting

Troubleshooting  if necessary will involve careful checking of locations and polarity of components. Re-solder all joints and check to make  sure  you  have  not  bridged across  between  any  two adjacent component legs.  The end  of  a  broken  hacksaw  blade  sharpened  on  an  emery wheel is a good tool for cleaning between soldered joints.

Technical notes

 

View the Datasheet for the Pic12F675.


When the beam is broken, the transistor is energised and the buzzer sounds.

Contact CdS electronics

Home Page