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Video Wall circuits
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555 Timer Circuits
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H Bridge Circuit
DIY HV Variable Cap
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4 Band Resistor
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Menci alarm produced schematic circuit diagram
The alarm circuit shown: alt="Menci alarm produced schematic circuit diagram"> Turn the power switch SW1, alarm electrical work.
Elderly lost alarm circuit
11A by the component and other components RMIB multivibrator, when the old man lost not more than a certain distance, the receiver output pin output low, the time-base integrat
Three water full alarm circuit
Change the value Ri, R2, Cl, C3, can change the alarm tone. It uses KD9300 music integrated circuits.
Automatic distress alarm kit control circuit
Circuit works: When the patient usually upright, packed in kit SQ mercury switch was turned off,
Low pressure break alarm circuit diagram
Circuit operation principle of the device shown in Figure. When the barbed wire Fe intact, LSE's O, feet collusion between its pin output high,
High pressure alarm circuit
High pressure alarm High sensitivity, high-voltage electric energy in the body from lOkV 2m at or away from the low-voltage mains (AC 220v) 0.3m at the alarm device yuan less device, the circuit is simple, easy to manufacture, small in size, easy to use.
Multi-way pocket alarm circuit
This is a two-way can set the alarm circuit which uses a Schmitt IC, with responsive and sound and light show, small size, low power consumption, all of the elements is only 13, a very low cost. This circuit is divided into two parts by the A, B and R4,
Telephone line burglar alarm circuit diagram
Phone alarm device can monitor and prevent unlawful misappropriation of your telephone line. When someone in your telephone line and the machine thefts from outside the alarm on the issue of interference signals, so thieves can not dial, and the light was stolen
Over-temperature alarm circuit
It uses a negative temperature coefficient thermistor for temperature sensing element Rt. By the resistor Ri, Rs, , potentiometer RP and thermistor R. Composition temperature bridge; by the transistor VTi, VT2 constituting the differential amplifier; by the transistor and diode
Manpower sensing alarm circuit
As shown in manpower inductive alarm circuit, simple and practical, when a person's hand near the sensing line, the alarm will send out alarm sound, which is very suitable for the male electrical burglar alarm. Induction line L is a long lo ~ 50cm of wire,
Automated Attendant burglar alarm circuit
It shows an automatic unattended burglar alarm circuit, mainly for family night, warehouses and other occasions automatic unattended. The circuit consists of pyroelectric infrared sensor light control circuit
Water alarm circuit
When the water boils, it is not only the police, but also cut off the heater power. Temperature sensing element with a fluorescent neon light bulb restructuring within the starter.
Induction high pressure alarm circuit
It uses KD153 type "ding-dong" music IC, issued a "ding-dong" sound alarm. d = 221611 " There /dianlu/safe/201303/160666.htm" refrigerator door alarm circuit.
One of the high-pressure sensing alarm circuit
By the 555 IC A composed of a non-steady-state self-excited multivibrator. When the sensor very close to the high-voltage electrified body, the piezoelectric ceramic sheet B out alarm. When it is close to the frequency electric field, cricket issue vibrato; close when the electrostatic field, emit electrical flute-like sound straight.
Smoke alarm circuit
Circuit works: When the gas sensor MQK-2 surface adsorption or smoke when combustible gas, which inter-electrode resistance BL plummeted, this time by the Rp2, R1 and BL electric poles between resistance partial pressure node C potential drop, when it fell to the potential after less than 1/3 Vcc only flip IC1 output low to stop the alarm.
Natural gas stove flame alarm
After the gas stove ignition, closing switch S, the circuit is in working condition. Phototransistor VT1 by flame before irradiation, low resistance state, the transistor VT2: saturated conduction, VT3 and integrated sheet music collector connected to
Over-temperature alarm and cooling circuit
This is the over-temperature alarm and a cooling by the CD4011 four NAND gate integrated circuits, and for monitoring the temperature of the oven used. When the thermostat circuit failure or power outage, the inside temperature is above or below the allowed
Vibration burglar alarm circuit
It uses the HL-169B-type voice alarm IC A. It can be used for safe, glass doors, car doors and windows burglar alarm and other occasions. When the thieves beat with violence such items that vibration of the piezoelectric ceramic sheet A, crystal thyristor V
SOS Alarm centralized control circuit
SOS Alarm centralized control circuit can be used to call a hospital bed, can also be used in multi-storey buildings, dormitories, warehouses and other places of anti-theft alarm. The circuit shown in Figure l3-64. The circuit shown in three-channel
Disconnect anti theft alarm circuit
It uses reed KR V control thyristor conduction, with 555 integrated circuit path consisting multivibrator as an alarm generator. When the door is closed, the permanent magnet close to the reed switch KR, with normally closed contacts reed contacts open,
Double limit temperature alarm circuit
The double-limit temperature alarm circuit by the temperature detection control circuit, the temperature indicating circuit and sound the alarm circuit, as shown in FIG. Components Selection R1 ~ R5 use 1 / 4W metal film resistor or a carbon film resistors.
Water Activated Alarm circuit
The circuit uses a 555 timer wired as an astable oscillator and powered by the emitter current of the BC109C. Under dry conditions, the transistor will have no bias current and be fully off. However as the probes get wet the transistor will conduct and sounding
The second phase alarm circuit
A capacitor Cl and resistor Ri-R3 consisting negative sequence voltage filtration device. Resistors and capacitors to meet the following requirements: Ri Ra-Rz 5.5/C1 (KN) form
Burglar alarm circuit
A simple burglar alarm circuits, sensors pyroelectric sensor IRA-E100SZI. When human movement is detected, the pressure on the electric buzzer alarm whistle. Sensor receives si
Alarm interface circuit
Alarm interface circuitry. As shown, the two-color light-emitting diode display. When LAi is high level t and LBi is low, the green light-emitting diode display; on the contrar
Simple and practical electric vehicle anti-theft alarm circuit diagram
As environmental awareness increases, the electric car has been poured into our family, become an indispensable part of peoples transport. How to prevent the electric car theft
A three-alarm phase circuits
As shown in (a), KAi, KA2, KA3 intermediate relay, connected to the outlet end of the low-voltage circuit breakers total. Alarm circuit connected to the backup power supply or
The driver alcohol detection alarm controller circuit diagram
As shown in FIG alcohol detection alarm controller circuit. QM-NJ9 for alcohol gas sensors, if detected the odor of alcohol, the AB-QM-NJ9 between resistance becomes smaller, t
Hydraulic oil Automotive LED Alarm SL322C schematic
As shown in FIG hydraulic oil for automotive LED alarm circuit. The circuit consists of a light emitting diode driver SL322C (IC), integrated voltage regulator circuit CW7809 (
Treasury temperature measurement alarm circuit diagram F007 5G1555 F033
As shown in FIG measuring temperature alarm circuit to the Treasury. The device consists of inverting amplifier IC1, comparison amplifier IC2, low-frequency multivibrator IC3,
Weak light alarm SCZ07 a circuit diagram
As shown in FIG weak light alarm circuit. The core of the oscillator circuit for the alarm SCZ07. Its input signal by the potentiometer W, control, output signal photoresistor
High sensitivity alarm
As shown in the simplified block diagram of the high sensitivity of the alarm circuit, wherein the photoresistor LDR and three ordinary resistor connected. Thus, when the light
Surveillance Bug Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
DIY HV Variable Capacitor
DIY PMA Alternator Plans
Digital Signal Integrity