Simple and reliable GSM security. Encyclopedia of radio electronics and electrical engineering

Encyclopedia of radio electronics and electrical engineering / Security and alarm via mobile communication

 Comments on the article

This article presents a diagram of an easy-to-make security alarm for use with a GSM (and not only) cell phone. This scheme allows you to manage up to 9 numbers on your cell phone (drawn on 2). The numbers are called one by one after the call has been dropped or dialing has failed or the called party is not available. Also, the scheme allows you to receive a signal to disarm for an unlimited number of numbers entered in the filter, thereby protecting against unauthorized numbers. The scheme can show what state the object is in, armed or disarmed. All these services are free of charge and do not charge money from the account, only the fee is charged if the called subscriber picks up the handset, for listening, at the time of operation, of the room. The phone is constantly charged until the number is dialed.

(click to enlarge)

The main control core is the BOS (signal control unit), the board is taken from a luminous cord for the phone, which is hung around the neck. It is sold in any mobile phone store and costs 60 rubles. When you call the phone, it starts blinking, thereby controlling the call from the phone, and turns off the charging of the cell phone. when charging, the vibrating alert required for the release signal will not work.

Any cell phone is fine. Siemens 52 models were taken, in it the keys were soldered to the standard connector with thin wires, except for pins 5 and 6, the contacts are written conditionally. Keys 6,9 were taken and hang up. they have one common path. The galvanic isolation of the circuit and the telephone is performed by AOD101A optocouplers, instead of them, reed relays were previously used.

Cell phone setup:

1. Ringtone and backlight turn off, vibrate alert is on.
2. The call filter is turned on, the numbers allowed to control the removal signal are written there.
3. Hot calls 6 and 9 are filled with the numbers of called subscribers.
4. Forwarding is set anywhere after 5 seconds if the subscriber does not answer (this is not necessary).

The circuit is powered by a constant voltage of 9 volts, to power the BOS, there is a separate DA2 stabilizer that outputs 3 volts, it is adjusted by the resistance R2, the charger is standard, if a car charger is used, there may be interference from it affecting the BOS, as evidenced by its constant blinking. BOS power can be seen from the battery where it stood, the diodes are soldered instead of one or two taps to the LEDs, the flooded LED is left for control. BOS is installed in the vicinity of the cell phone (PT) itself.

How the security system works:

The trigger signal from any control system is fed to the transistor VT4, it opens and, through the normally closed contact of the relay K1, powers the optocouplers of contacts 6 and 9. At the moment, the counter DA1 has prepared contact 6 or 9 for operation, and the optocoupler, on which there will be a positive signal, will close corresponding CT contact. The call is started. The biofeedback system detects the communication signal with the operator and opens the circuit with the relay contact K1, at the same moment the meter will switch to another contact and will be ready. After a call is made, a call is dropped or a failure occurs at the moment of dialing, the connection is lost, the BOS is turned off and after the time necessary for the ST to return to the normal menu state (for Siemens, somewhere around 15 seconds), the K1 relay returns to its normal state and powers the optocouplers again, but the call will go differently contact, and so on in turn, until the "operation +" signal is removed.

The positive wire of the charger is connected to the "charger +" contact.

If feedback is needed, then the "armed" contact must be connected to the contact that will give a positive contact. In this case, when a PT is called, the call will be reset automatically by pressing the end button, at the same moment a "disarm" signal will appear, which can be used for the same purposes. In turn, the protection will show that the object is under protection. With the guard removed, just beeps will go!

All questions at: schurik_84 [dog] mail.ru

Publication: cxem.net

See other articles Section Security and alarm via mobile communication.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive Health forecast for 2030 12.03.2007 The World Health Organization has published a detailed forecast of the state of human health in 2030. By this time, the risk for an infant to die before reaching the age of five will be halved compared to the current situation. But in 2030, 6,5 million people will die from AIDS (2002 million in 2,8). Smoking and related diseases will kill 8,3 million people (up from 2005 million in 5,4). Depression is the second most common long-term illness after AIDS. The main causes of death, as now, will remain heart attacks and strokes. They will be followed by pneumonia, AIDS, emphysema and tuberculosis. How accurate were previous WHO predictions? The first such forecast was made in 1996. There are already more AIDS patients on the planet, and the prevalence of tuberculosis is less than predicted then. It is possible that there are errors in the new forecast, although now much more extensive statistics for different countries were used for work than last time. But much depends on how the economic development of poor countries goes. If the standard of living of their population rises, people will die after 70 years from diseases of the heart and blood vessels, and not at 3 years from dysentery.

Other interesting news:

▪ MAX77801 - new buck-boost regulator for battery power

▪ Intel LTE modems

▪ Powering wearable electronics with radio waves

▪ Garlic makes men more attractive

▪ wifi on sheep

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site For a beginner radio amateur. Article selection

▪ article Lens and glasses. History of invention and production

▪ article Who did Hitler consider his main enemy in the USSR? Detailed answer

▪ article Host of radio programs. Job description

▪ article Color-musical installation with pulse-number control of trinistors. Encyclopedia of radio electronics and electrical engineering

▪ article Field effect transistors KP901 - 3P930. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages ​​of this page

Arabic	Hebrew	Polish
Bengali	Hindi	Portuguese
Chinese	Italian	Spanish
English	Japanese	Turkish
French	Korean	Ukrainian
German	Malay	Vietnamese

Home page | Library | Articles | Website map | Site Reviews

www.diagram.com.ua
2000-2024