Mutchus

Motorbikes are often a target for thieves.  Here is an alarm that’s loud, cheap and simple  to build. Arming and disarming the alarm is  done with a hidden switch, S1. This tiny circuit  does not unduly load the battery, as it draws  very little current in the standby condition. To activate the alarm, turn or press the hid-den switch S1 to the ‘on’ position. If anyone  attempts to start the motorbike, +12 volts  from the ignition switch (connected to ‘B’)  causes transistor T1 to conduct and switch on  T2. The siren (LS1) then sounds for about 20  seconds, the period being determined by FET  T3 wired as a monostable timer. The siren is  a high-power ready-made piezo horn of the  self-oscillating type.   Circuit diagram : Cut-rate Motorbike Alarm Circuit Diagram   Another piezoelectric component in the cir-cuit has a different purpose — Bz1 detects  attempts to tamper with the vehicle, or move  it without starting the engine. The piezo trans-ducer element should be mounted in suc...

This is a simple Motorcycle Alarm With Transistor Circuit Diagram . It's designed to work at 12-volts. But - if you change the relay for one with a 6-volt coil - it'll protect your "Classic Bike". The standby current is virtually zero - so it won't drain your battery. Motorcycle Alarm With Transistor Circuit Diagram Any number of normally-open switches may be used. Fit the mercury switches so that they close when the steering is moved or when the bike is lifted off its side-stand or pushed forward off its centre-stand. Use micro-switches to protect removable panels and the lids of panniers etc. While at least one switch remains closed - the siren will sound. About one minute after all of the switches have been opened again - the alarm will reset. How long it takes to switch off depends on the characteristics of the actual parts you've used. You can adjust the time to suit your requirements by changing the value of C1 and/or R3. The circuit is designed to use ...

Burglar alarm circuit or Theft alarm circuits are available in several forms. The above circuit was one of that kind using timer IC 555 as the main component. The circuit is very easy to construct and the cost of this circuit is also very less. So we can implement this circuit by our own and install this circuit in our home so that you can improve your knowledge and it also adds protection to your home. Using IC 555 Burglar Alarm Circuit Diagram The working of this circuit is very easy to understand.In the above circuit IC 555 was used as a A stable multi vibrator.The A stable multivibrator puts out a continuous stream of rectangular pulses having a specified frequency. Thus by using the A stable multivibrator we can produce continuous frequency which was given as input to the speaker which makes an alarm sound in case of any disturbance in its trip wire. Pin diagram of IC 555 was given below for your better understanding. Now we can see how we can change the A stable Multivibrato...

Small, portable, anti-bag-snatching unit Also suitable for doors and windows control Circuit diagram Parts: R1 330K 1/4W Resistor R2 100R 1/4W Resistor C1 10nF 63V Polyester or Ceramic Capacitor C2 100µF 25V Electrolytic Capacitor Q1 BC547 45V 100mA NPN Transistor Q2 BC327 45V 800mA PNP Transistor SW1 Reed Switch and small magnet (See Notes) SPKR 8 Ohm Loudspeaker (See Notes) B1 3V Battery (two A or AA cells wired in series etc.) Device purpose: This circuit, enclosed in a small plastic box, can be placed into a bag or handbag. A small magnet is placed close to the reed switch and connected to the hand or the clothes of the person carrying the bag by means of a tiny cord. If the bag is snatched abruptly, the magnet looses its contact with the reed switch, SW1 opens, the circuit starts oscillating and the loudspeaker emits a loud alarm sound. The device can be reverse connected, i.e. the box can be placed in a pocket and the cord connected to the bag. This device can be very useful in s...

Here is a simple ANTI-THEFT ALARM AND HORN . It generates a loud alarm when there is an attempt of theft. When the intruder opens the door, the circuit senses the attempt of theft and after 2 minutes, the alarm will be activated. The time delay is provided to help the user to leave after arming with the device.   ANTI-THEFT ALARM AND HORN

This water sensor alarm circuit diagram is designed using common electronic components. Thewater sensor alarm circuit may operate an active buzzer, to make a sound when is reached a certain level of water. Transistor Water Sensor Alarm Circuit Diagram Because water sensor and control circuit for buzzer are located on the same printed circuit board, indicator, together with 9 V battery and buzzer can be mounted in a compact case. When water reaches the sensor, the base of T1 is connected to the positive supply terminal. Therefore, T1 and T2 are open, so that buzzer BZ1, will be activated. Sensitivity reduction of the circuit can be done by increasing the value of R2.

In this circuit, the alarm will be switched on under the following four different conditions: 1. When light falls on LDR1 (at the entry to the premises). 2. When light falling on LDR2 is obstructed. 3. When door switches are opened or a wire is broken. 4. When a handle is touched. The light dependent resistor LDR1 should be placed in darkness near the door lock or handle etc. If an intruder flashes his torch, its light will fall on LDR1, reducing the voltage drop across it and so also the voltage applied to trigger 1 (pin 6) of IC1. Thus transistor T2 will get forward biased and relay RL1 energise and operate the alarm. Sensitivity of LDR1 can be adjusted by varying preset VR1. LDR2 may be placed on one side of a corridor such that the beam of light from a light source always falls on it. When an intruder passes through the corridor, his shadow falls on LDR2. As a result voltage drop across LDR2 increases and pin 8 of IC1 goes low while output pin 9 of IC1 goes high. Transistor T2 gets...

Description At the heart of this overhead detector (fire alarm) circuit is a precision integrated temperature sensor type LM35 (IC1), which provides an accurately linear and directly proportional output in mV, over the zero to +155 degrees C temperature range. This can be used as part of fire smoke detectors but do not use it as a home fire alarm system. The LM35 develops an output voltage of 10 mV/K change in measured temperature. Designed to draw a minimal current of its own, the LM35 has very low self heating in still air.  Here the output of the LM35 is applied to the non-inverting input of a comparator wired around a CA3130 opamp (IC2). A voltage divider network R3-P1 sets the threshold voltage, at the inverting input of the opamp. The threshold voltage determines the adjustable temperature trip level at which the circuit is activated. When the measured temperature exceeds the user-defined level, the comparator pulls its output High to approx. 2.2 V causing transistor T1 to b...

This is project of Simple Fire Alarm Circuit Diagram. This is a very simple circuit of a fire alarm when there is a fire an audible alert is activated. This fire alarm circuit should be placed in locations subject to fogoe its operation is simple, in a fire the smoke is enough to reduce the intensity of light to the LDR, triggering the system.  Super Fire Alarm Circuit Diagram

Small, portable, anti-bag-snatching unit. Also suitable for doors and windows control This circuit, enclosed in a small plastic box, can be placed into a bag or handbag. A small magnet is placed close to the reed switch and connected to the hand or the clothes of the person carrying the bag by means of a tiny cord. If the bag is snatched abruptly, the magnet looses its contact with the reed switch, SW1 opens, the circuit starts oscillating and the loudspeaker emits a loud alarm sound. The device can be reverse connected, i.e. the box can be placed in a pocket and the cord connected to the bag. This device can be very useful in signalling the opening of a door or window: place the box on the frame and the magnet on the movable part in a way that magnet and reed switch are very close when the door or window is closed. Personal Alarm Circuit Diagram : Personal Alarm Circuit Diagram Circuit operation: A complementary transistor-pair is wired as a high efficiency oscillator, directly drivi...