5 Simple Infrared Remote Jammer

This circuit can be used to ruin or jam infrared remote signal from TV or sound system. Its use is basically the same as the TV remote jammer, but this one uses only transistor and no IC required.

Remote jammer schematic

Part list:

R1 - 33 ohms 1/4W

R2 - 1 kilo ohms 1/4W

R3 - 10 kilo ohms 1/4W

R4 - 100 kilo ohms 1/4W

R5 -  120 kilo ohms 1/4W

C1 - 22uF electrolytic capacitor rated 10V

C2 - 10nF ceramic capacitor

Q1 - 2N2222A or similar NPN transistor

Q2 - 2N3905 or similar PNP transistor

PB - Push button

BAT - 4.5V battery

LED - Infrared LED (see LED pinouts in case you forgot)

2N3905 pinout

2N2222A pinout

Other Jammer Circuit:

TV remote jammer

FM radio jammer

7 Long Range FM Transmitter

This simple transmitter can transmit FM (frequency modulation) signals more than a mile away. Adjust trimmer C9 to fine tune the transmitter and use battery as a source to minimize noise.
Part List:
R1, R3, R9, R10 - 10 kilo ohms 1/4W
R2 - 22 kilo ohms 1/4W
R4 - 100 kilo ohms 1/4W
R5 - 1.2 kilo ohms 1/4W
R6 - 47  kilo ohms 1/4W
R7 - 120 ohms 1/4W
R8 - 390 ohms 1/2W
R11 - 47 ohms 1/4W
Pot1 - 5 kilo ohms potentiometer
C1, C5 - 0.33uF electrolytic capacitor rated 25V
C2 - 22uF electrolytic capacitor rated 25V
C3  - 10uF electrolytic capacitor rated 25V
C4 - 220nF
C6, C7 - 1000pF ceramic capacitor
C8 - variable capacitor not less than 40pF
C9 - variable capacitor not less than 22pF
Q1, Q3 - 2N2222A or similar NPN transistor
Q2 - 2N2906A or similar PNP transistor
L1 - VK220J or similar RFC inductor
L2 - 3 turns 18AWG magnet wire wound in 10mm diameter plastic former
L3 - 2 turns of 18AWG magnetic wire wound close to L2 using the same core where L2 is wound. See diagram below.

2N2906A pinout

2N222A pinout

Inductor L2 and L3 construction

Note: This transmitter is for educational use only. Long range transmitter is illegal in some countries thus use it at your own risk.

1 Mobile Phone Detector

This project is a simple mobile cellphone detector circuit. As the phone receives or sends massage or call, it sends off signal. The emitted signal will be detected by the circuit and will cause the LED to light up and the buzzer to sound. You can use this circuit as decoration to your cellphone or use this as a detector to unauthorized use of cellphone in prohibited area. Any cellphone activities like sending or receiving SMS, sending videos or any form of data transmission can be detected by this simple circuit. R5 and C7 set the duration of the buzz and ON time of the LED for 1 sec (you can modify it using the 555 timer calculator in monostable mode). Click diagram to enlarge.

phone detector circuit

Part List:
R1, R2 - 2.2 Mega ohms 1/4W
R3, R6 - 1.2 kilo ohms 1/4W
R4, R5 - 10 kilo ohms 1/4W
R7 - 100 kilo ohms 1/4W
C1, C2 - 22pF ceramic capacitor
C3, C7 - 47uF electrolytic capacitor rated 16V
C4 - 220nF
C5 - 33pF ceramic capacitor
C6 - 4.7uF electrolytic capacitor rated 16V
C8 - 100nF
ANT -  just a piece of conductor less than 1ft
Q1 - 2N2222 or similar NPN transistor
LED - red led (see LED pinout in case you forgot)
Buz - 12V buzzer
555 - LM555 or similar timer IC
IC - CA3130 or similar
Bat - 9V to 12V battery

Parts pinout: click diagram to enlarge

CA3130 pins

555 pinout

2N2222 pinout

0 Simple Field Strength Meter

This simple circuit can be used to test generated signal from a wireless transmitter. On the circuit and adjust the potentiometer R4 until the reading of meter is zero. Using this circuit, you can test also if your FM radio jammer circuit or FM transmitter is working or not. When there is signal, the meter needle will move.

schematic diagram

Part List:
R1 - 560 kilo ohms 1/4W
R2 - 1.8 kilo ohms 1/4W
R3- 1.8 kilo ohms 1/4W
R4 - 5 kilo ohms potentiometer
D - 1N60 or similar germanium diode
Q - 2N2222 or similar NPN transistor
M - 1mA meter or any meter available
Ant - 6 inches wire
Bat - 1.5V to 6V battery

2N2222 pinout

5 Wireless Microphone Circuit

The circuit is similar to FM bug but just to give emphasis, the use of this transmitter is for replacement of wireless microphone. The transmitter can be tuned to standard 90 to 108MHz FM band.

schematic diagram

Part List:
R1,R4, R7 - 5.6 kilo ohms 1/4W
R2 - 10 kilo ohms 1/4W
R3 - 4.7 kilo ohms 1/4W
R5, R8 - 2.7 kilo ohms 1/4W
R6 - 1.2 kilo ohms 1/4W
R9 - 200 ohms 1/4W
C1, C2 - 4.7uF electrolytic capacitor
C3, C6 - 100nF
C4 - 4.7pF
C5 - 5-60pF variable capacitor
Q1 - 2N2222, CS9013 or similar NPN transistor
Q2 - 2N2222, CS9013 or similar NPN transistor
L- 6-8 turns #22AWG magnetic wire diameter same as the pencil
Mic - electret microphone

0 Simple Remote Control Checker

This is a simple infrared (IR) remote checker.  The two versions are shown below, the one using NPN transistor and other using PNP transistor. Both of the remote checkers can be used to test remote control of TV, DVD players, and other devices or equipment.

Part List:

R - 47 kilo-ohms 1/4W

LED - 3mm or 5mm red LED (yellow, orange can be used also)

LDR - any light dependent resistor that varies from 300   to 10Meg

Q1 - 2N3906, 2N4403, CS9012 , or any similar PNP transistor

Q2 - 2N2222, 2N3904, CS 9013, or any similar NPN transistor

 Parts diagram click to enlarge:

PNP pins

NPN pins

LDR

Note: Increasing the value of R increases the circuit sensitivity. Meaning if the LED is always on even no light is directed to the LDR, try decreasing the value of R. On the other hand, if the LED will not light up even a light is directed to the LDR, try increasing the value of R. 

0 FM radio jammer

This circuit is very similar to fm bug. What this circuit do is block fm radio frequency near your area or  vicinity.

Fm jammer schematic

Inductor L1 is made of 6 turns of  #16AWG magnetic wire wound on a 9mm diameter plastic.

Note:  The circuit is for educational purposes only. Do not play with it since distracting radio signals is illegal in some areas.

0 TV remote jammer

The tv remote control transmits signal to the tv in pulses at around 37.5kHz frequency. Every button in your remote when pressed  has an equivalent pulses  or signal codes.This remote jammer circuit will transmit pulses of the same frequency as the remote to confuse your tv set from decoding the transmitted signal.

circuit schematic

Part list:
2-1k resistor
2-10nF
1-5k pot
1-555
1-100
1-2n2222
1-IRled
1-1.2k
1-9V battery

Operation:
The heart of the circuit is the 555 timer IC operated in astable mode.The circuit will output  series of pulses at a frequency of 18kHz up to 48kHz by simply adjusting the 5K potentiometer. What you will do is adjust the potentiometer until it jives to the frequeny of your TV remote or until the signal is ignored by the TV set.
See 555 calculator if you are planning to use other values of capacitor and resistor in your circuit.

Note: The circuit is primarily for educational purpose only, other than this  use it at your own risk.

4 FM bug: simple transmitter

This simple fm transmitter can be tuned to standard fm receiver and has a range of around 300 meters, thus suitable for monitoring purposes. It is designed as simple as possible with minimal parts without compromising its stability. The transmitter is very similar to wireless microphone circuit. Click diagram to enlarge.

simple FM transmitter schematic

How to make the FM transmitter:

Gather the following materials:

R1 - 120 ohm resistor 

R2 - 120K ohm resistor 

R3, R5, R6 - 10K  ohm resistor 

R4 - 1.2Meg ohm resistor 

R7 - 1K ohm resistor 

C1, C2 - 100nF capacitor 

C3 - 10nF capacitor 

C4 - 4-80pf variable capacitor / trimmer cap

C5 - 4.7pf capacitor 

Q1, Q2 - 2N2222 transistor or any general purpose transistor

L1 - 8 turns of #22AWG  wire wound around a pencil or pen

antenna - 1.5ft solid wire

Electret Microphone

9V battery

2N2222 pinout

How the FM circuit works:

Sound is converted to electrical energy by the electret mic, then this energy is feed to transistor Q1. Transistor Q1 serves as an amplifier of the signal. The heart of the fm transmitter is the oscillator circuit which is the trimmer capacitor C4,inductor L1 and transistor Q1. C4 and L1 combination provides the value of frequency on which the transmitter is to be tuned. Materials listed above are not critical, you can replace it with its nearest value.

 *see LC calculator to select the inductor L1 and capacitor C4 values for the tuning frequency of your choice.

FM Transmitter testing:

1.Turn on  fm receiver and look for frequency that there is not used

    by any fm channel or fm station in your area.

2.Turn on the fm transmitter and gently adjust the trimmer capacitor C4

   until the fm receiver pick up the signal from your transmitter.

3.If ever the fm receiver cant pick the transmitter signal dispite of trying 

   many times, try squeezing or stretching the inductor and repeat step 2

1 Wireless Power (Witricity) project

Wireless electricity or wireless power transmission is one of the emerging technologies today. The idea of this technology is transmitting power from a source to any receiver using the free space, same as the  TV and  radio transmission or same as your wireless lan or WIFI. Some of the uses as of the moment are for  charging iPod, cellphones, digital cameras, mp3, iPhone and other electronic devices.

How it works:

Wireless power operation

1. Source coil powered by a main supply usually your power outlet

2.Yellow line is  the energy flow from the source that is receiving coil

3.Conducting material that blocks some transmitted energies (blue line)

4.The receiving coil that is connected to the device like your cellphones, iPods, mp3, and others.

Resonant Frequency:

To achieve better wireless power transmission, the Power source must be of the same frequency of receiving coil. 

Power source frequency F1 = Receiving coil frequency F2

F1=F2=  1/(2π√(L2*C2))

         *for  more LC frequency balancing use LC frequency calculator

Resonant transmission

Proposed  project:

Lighting  LED via wireless power

Materials:

A. Source---5V sine wave or square wave source @135kHz frequency

              *555 IC square wave signal generator is a candidate see more

               on 555 timer ic

B. C2----940nF cap or parallel 2 470nF Mylar or ceramic capacitor

C. L2----1.46uH air coil inductor or 15m  #24AWG magnetic wound 

               @ 2 inches diameter

D. L1---100 turns #20AWG magnetic wire @ 2 inches diameter or larger

7 Simple FM transmitter powered by 1.5V battery

This simple  FM (frequency modulation) transmitter is powered only by a 1.5V battery and uses only 1 transistor.The frequency of this transmitter is controlled by the L-C resonance circuit and operates from 80 to 110 MHz.

simple FM transmitter schematic

The inductor L1 is made of 8 turns of  #22AWG magnetic wire wound  with the diameter of 4-5cm or diameter of a pencil. The antenna is a 6 inches copper wire connected at the middle of L1 inductor. Other parts

are not critical and can be replaced by its closest value. Resistor are 1/4 watt type and capacitors are ceramic except  the 10uF electrolytic  capacitor. 5-60pF capacitor is a trimmer type or variable type.

Note: Modifying this simple fm transmitter circuit such as increasing its power capacity is illegal.Review the fcc limits regarding fm transmitter if you are planning to build a more powerful one.

Notes by Acme Fixer:(Thanks!!)
1. Add 0.01uF capacitor across 1.5V supply near the transistor.
2. You can remove the antenna.
3. Mic is an electret condenser microphone type.
4. See the rest of his recommendation based on his experience in building the circuit. See comment section below.

4 motor speed control by transistor

This motor speed control is very cheap, simple, and easy to assemble since its control unit is only a transistor.The transistor is TIP41C or any type of the same specification and current capacity.The voltage is about 12V DC or more and motor type is 6-12V and max current of 3A.
You can control the speed of motor by adjusting the potentiometer. Increasing the resistance means decreasing the speed while decreasing the resistance means increasing the speed.
Because of its simplicity, anyone can make this project and assemble it even if not an electronic hobbyist.

8 simple electronic doorbell circuit by 555 timer IC

schematic diagram of electronic doorbell circuit

Simple electronic doorbell circuit (monostable 555  timer IC)

This project  is  a simple electronic doorbell circuit powered by a battery source ranging from 6 volts to 12 volts. This doorbell circuit is powered by a 555 timer IC operated in monostable mode. The use of the timer IC is to set the time delay for the doorbell to ring. The 100K resistor and 33uF capacitor sets the time delay about 3.6 seconds of continuous ringing. Increasing the value of resistor and capacitor increases the time delay about the product of resistor-capacitor combination times 1.1 (1.1RC).
The switch S1 is a push button that will activate the electronic doorbell. The 10K resistor across the S1 and supply voltage provides protection of false triggering of 555 timer.
The buzzer to be used must be self oscillated type or having a built in oscillator for this doorbell circuit to function well.
For  persons with some problem in hearing, you can modify the door bell circuit by replacing the buzzer to LED and 150 ohm resistor (see diagram below), or you can put this LED and resistor in parallel to buzzer for better functionality
The LED is preferably blinker type, but an ordinary one is just okay.

schematic diagram of simple electronic doorbell circuit for deaf

Simple electronic doorbell circuit (astable 555  timer IC)

Another version of simple electronic doorbell is shown bellow. This type of electronic doorbell uses the same 555 timer IC but it is operated in astable operation a generating an audible sound of 2880 Hz. Another difference of this doorbell circuit is the buzzer is replaced by a speaker. The sound frequency is set by the resistors 1K, and 2K, and 100nF capacitor. Increasing their value lowers the pitch of the doorbell sound.

The same with the electronic doorbell above, you can replace the speaker with an LED as an indicator. Advantage of this type of electronic doorbell is you can use a buzzer or speaker while the version above can’t. Disadvantage of this version is it requires more parts and you are going to push the button (S1) all the time for the doorbell to sound.

another version of doorbell