INFRARED MOTION DETECTOR

• Here is the circuit diagram of an infrared motion detector that can be used to sense intrusions.Infra red rays reflected from a static object will be in one phase, and the rays reflected from a moving object will be in another phase.The circuit uses this principle to sense the motion.
• The IC1 (NE 555) is wired as an astable multivibrator .The IR diode connected at the output of this IC produces infrared beams of frequency 5Khz.These beams are picked by the photo transistor Q1
• At normal condition ie; when there is no intrusion the output pin (7) of IC2 will be low.When there is an intrusion the phase of the reflected waveforms has a difference in phase and this phase difference will be picked by the IC2.
• Now the pin 7 of the IC 2 goes high to indicate the intrusion.An LED or a buzzer can be connected at the output of the IC to indicate the intrusion.
  
  NOTES:
• Comparators IC2a and IC2b are belonging to the same IC2 (LM1458).So the power supply is shown connected only once.No problem.
• When there is disturbance in the air or vehicles passing nearby,the circuit may get false triggered.
• POT R5 can be used for sensitivity adjustment.

T.V.TRANSMMITER CIRCUIT

• Here, uses FM modulation for sound and PAL for video modulation.
• The audio signal to be modulated is pre-amplified using the transistor Q1 and associated components.
• The transistor Q2 has two jobs: production of carrier frequency and modulation.
• The pre-amplified audio signal is fed to the base of transistor Q2 for modulation. Capacitor C5 and inductor L1 forms the tank circuit which is responsible for producing the carrier frequency.
• The video signal is fed to the emitter of transistor Q2 via POT R7 for modulation. The modulated composite signal (audio+video) is transmitted by the antenna A1.
  
  
• NOTES:
• Assemble the circuit on a good quality PCB.
• Inductor L1 can be made by making 4 turns of 24SWG enameled copper wire on a 6mm dia: plastic former.
• T1 can be a radio frequency transformer with built in capacitor. (Can be found on old transistor radio boards).
• Antenna A1 can be a 1M long copper wire. (Experiment with the length to get optimum performance).
• This transmitter is working in VHF band somewhat between 50 – 210MHz.
• This transmitter is compatible only with PAL B and PAL G systems.

REMOTE CONTROLL TESTER

1. This is a simple remote controller tester circuit based on infrared sensor IC TSOP 1738.
2. When the IR waves fall on the sensor it output changes to low state.This makes the transistor Q1 ON and LED will blink according to the code contained in the sign.
3. So for press of each button the LED blinks in different ways.This is a good indication of the working of remote.The diode D1drops 0.7 V to give the IC ~ 5V supply from the available 6V .R2 is a current limiting resistance.
   NOTES:
4. Use a 6V battery to power up the circuit.
5. This circuit can be used to test remotes operating in the 38Khz carrier frequency.Almost all remotes fall into this category so no problem.

FM RADIO JAMMER

1. This circuit can be used to jam FM radios.
2. The circuit is nothing but a classic signal transistor oscillator operating in the VHF region.
3. Working principle of this circuit is very simple and straight forward.
4. powerful VHF oscillations from the circuit will interface with the FM signals to nullify it.
5. This circuit is intended only for fun and i request you not to misuse it.
   
   NOTES:
6. For L1 make 6 turns of 16AWG enamelled copper wire on a 9mm plastic former.
7. The circuit can be powered using a 9V PP3 battery.
8. For extended range, use an antenna.
9. A 30cm long wire connected anywhere on the coil will do for the antenna.
10. For better performance, assemble the circuit on a good PCB.

T.V.REMOTE JAMMER

1. Here is the circuit diagram of simple but highly effective TV remote jammer circuit.
2. Most of the TV remotes have 38KHz operating frequency.
3. A flood of IR beams in the same frequency can easily confuse the TV receiver and this is the operating principle of our jammer.
   
4. The circuit is nothing but an astable multivibrator based on NE555 IC.
   
5. The output of NE555 is amplified using a PNP transistor SK100 to drive the IR LEDs. Not only TV remotes, but any IR remotes operating in the 38KHz frequency region can be also jammed by using this circuit. NOTES:
6. The circuit can be assembled on a Vero board.
7. Use a 9V PP3 battery for powering the circuit.
8. Mount the IC on a holder.
9. POT R4 can be adjusted to exactly match the jammer’s frequency to the remotes frequency. This adjustment is very essential for effective jamming.