Door Open Sensor

Each Door Open Sensor is made up of two parts. A magnet and a switch. The magnet will be attached to the door. The switch will be attached to the door frame. Depending on the relative position of magnet and switch, the switch will open or close. With the proper placement, this will allow the detection of the door being opened or closed Once the switch is wired to an input of the Frotcom GPS/GPRS device; these changes will be detected and communicated to the Frotcom Data Center. Then, Frotcom will update the door open status for that vehicle and check for alarm conditions.

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Main features

Here are some of the main features of the Door Open Sensor:

• Thermoplastic enclosure
• Flat design
• Long life
• Non-contacting principle
• 1 reed contact
• Actuating distance up to 60mm
• Actuating surface marked by protrusion
• Pre-wired cable with length 1m
• Protection class IP 67

BURGLAR ALARM

               

A burglar alarm is a system designed to detect intrusion – unauthorized entry – into a building or area. They are also called security alarms, security systems, alarm systems, intrusion detection systems, perimeter detection systems, and similar terms.

Burglar alarms are used in residential, commercial, industrial, and military properties for protection against burglary (theft) or property damage, as well as personal protection against intruders. Car alarms likewise protect vehicles and their contents. Prisons also use security systems for control of inmates.

Some alarm systems serve a single purpose of burglary protection; combination systems provide both fire and intrusion protection. Intrusion alarm systems may also be combined with closed circuit television surveillance systems to automatically record the activities of intruders, and may interface to access control systems for electrically locked doors. Systems range from small, self-contained noisemakers, to complicated, multi-area systems with computer monitoring and control.

GAS SENSOR MQ-6

Whenever there is LPG concentration of 1000 ppm (parts per million) in the area, the OUT pin of the sensor module goes high. This signal drives timer IC 555, which is wired as an a stable multivibrator. The multivibrator basically works as a tone generator.

Output pin 3 of IC 555 is connected to LED1 and speaker-driver transistor SL100 through current-limiting resistors R5 and R4, respectively. LED1 glows and the alarm sound to alert the user of gas leakage. The pitch of the tone can be changed by varying preset VR1. Use a suitable heat-sink for transistor SL100.

 

Gas Sensor MQ-6

 FEATURES

High sensitivity to LPG, ISO-butane, propane

Small sensitivity to alcohol, smoke.

Fast response.

Stable and long life

Simple drive circuit

APPLICATION

They are used in gas leakage detecting equipments in family and industry, are suitable for detecting of LPG, ISO-butane, propane, LNG, avoid the noise of alcohol and cooking fumes and cigarette smoke.

TEMPERATURE SENSOR LM35

General description of  LM 35

The LM35 is an integrated circuit sensor that can be used to measure temperature with an electrical output proportional to the temperature (in ^oC) The LM35 series are precision integrated-circuit temperature sensors, whose output voltage is linearly proportional to the Celsius (Centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in ° Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of ±1⁄4°C at room temperature and ±3⁄4°C over a full −55 to +150°C temperature range. Low cost is assured by trimming and calibration at the wafer level. The LM35’s low output impedance, linear output, and precise inherent calibration make interfacing to readout or control circuitry especially easy. It can be used with single power supplies, or with plus and minus.

                                                           

LM 35 Temperature Sensor 

                                                      

Features

1.      Calibrated directly in ° Celsius (Centigrade)

2.      Linear + 10.0 mV/°C scale factor

3.      0.5°C accuracy guarantee able (at +25°C)

4.      Rated for full −55° to +150°C range

5.      Suitable for remote applications

6.      Low cost due to wafer-level trimming

7.      Operates from 4 to 30 volts

8.      Less than 60 μA current drain

9.      Low self-heating, 0.08°C in still air

10.  Non linearity only ±1⁄4°C typical

11.  Low impedance output, 0.1 W for 1 mA load

 Advantages of LM35  to Measure Temperature?

You can measure temperature more accurately than a using a thermistor.  

The sensor circuitry is sealed and not subject to oxidation, etc.

The LM35 generates a higher output voltage than thermocouples and may not require that the output voltage be amplified.

Working of LM35:

The scale factor is .01V/^oC. 

The LM35 does not require any external calibration or trimming and maintains an accuracy of +/-0.4 ^oC at room temperature and +/- 0.8 ^oC over a range of 0 ^oC to +100 ^oC.

Another important characteristic of the LM35DZ is that it draws only 60 micro amps from its supply and possesses a low self-heating capability. 

The sensor self-heating causes less than 0.1 ^oC temperature rise in still air. 

It has an output voltage that is proportional to the Celsius temperature.