Manual Reference

This circuit is a high-performance charger for gelled-electrolyte lead-acid batteries. This charger quickly recharges the battery and shuts off at full charge. Initially, charging current is limited to 2 A. As the battery voltage rises, current to the battery decreases, and when the current has decreased to 150 mA,  the charger switches to a lower float voltage, which prevents overcharge.

 

Circuit diagram :

12V Battery Charger Circuit Diagram

 

When the start switch is pushed,  the output of the charger goes to 14.5 V. As the battery approaches full charge, the charging current  decreases and the output voltage is reduced from 14.5 V to about 12.5 V, terminating the charging. Transistor Q 1 then lights the LED as a visual indication of full charge.

The factory will go through the certification of cell phone jammer .
At present, domestic annual output has reached 400 million, approximately 50% of the global mobile phone production. China has become the worlds largest mobile phone production base. Each of the past three years, has a 500-700 model of about 100 million mobile phone to put the domestic market, is the worlds largest mobile phone consumer market. With the increasingly fierce market competition, but also exposed some problems, such as the decline in product quality and after-sales service is not in place. One of the most prominent is the increasingly rampant smuggling, counterfeit, assembled and refurbished mobile phone violations of these products or impurities, seq charge superior, not only seriously disturbed the normal mobile phone market order, resulting in the loss of state tax revenue, and serious damage to the legitimate interests of legitimate manufacturers and consumers. The subfactory has gotten the certificate of cell phone jammer .
The country has developed a number of policies and regulations. The mobile phone market order rectification program in four measures: elimination of the underground factories of the illegal production of mobile telephones. Clean up all kinds of illegal counterfeit, assembled and refurbished, the smuggling of mobile phone products. Strengthen the supervision of product quality and after-sales service, strict mobile phone into the gateway, and conduct quality supervision and inspection and testing, manufacture and sale of substandard quality of mobile telephone conduct punishable by law. Found in the market to check suspected criminal clues, the administrative law enforcement departments and industry management department should be transferred to public security organs shall be investigated and dealt with. More research is needed for this type of cell phone jammer .This kind of mini portable cell phone jammer is very popular in the domestic market
Serious harm, vile and criminal cases and violent resistance to law in the public security organs will be held criminally responsible. In order to ensure the effective implementation of these measures, the Ministry will depend on the specific circumstances of the composition of inspection teams in conjunction with relevant departments, the problem is more serious in-depth areas of supervision and inspection, to realistically grasp the special rectification. The breakdown of the mobile phone industry. Most Chinese enterprises are SMEs, and among the worlds top 500 very low probability. Warlords disputes under the intensified market competition. Market environment is not continuous, controlled, sustained and varied, complex and changeable enables marketers must be pragmatic and efficient operation. Many experts of cell phone jammer devote much spare time to improve the quality of cell phone jammer .

 Introduction (a) BH-201 series of mobile phone jammer is the company adopts foreign advanced technology, combined with the actual situation of the mobile communication of well-developed high-tech products, it can in the diameter of 25-100 meters within the cut off GSM / CDMA / AMPS / DCS / PHS mobile phone signal, and answer the phone can not play, but does not interfere with other electronic equipment, cell phones cut off to leave the range, you can resume normal use. And the human body without any damage. Therefore, the product can be installed in gas stations, oil depots, gas stations and other flammable places; forces, public security and government agencies to ban cell phone and some other places; hospitals, conference rooms, concert halls, cinemas, schools, library, examination room, and churches need to prevent cell phone interference, quiet place. Currently, cell phone jammer is widely used in industries and locations.(B) the advantages of a companys products. Appearance grade: aluminum shell, the surface color pattern can be determined based on customer preferences; 2 reliable performance: the use of foreign software and chip technology, templates. 3 at the most affordable price: The company adopts advanced management mode, sought to reduce production costs, thereby reducing the cost of customers; 4 easy to install: just 1.8 from the ground can be nailed to 2.0 meters (mounting screws has distribution); 5 . lowest power: because it is the only designated State Secrecy Bureau research companies, to consider all aspects in the design of more mature, as not affecting the normal radio communication network, especially in hard materials, the power control in the Ministry of Information Industry, the following requirements of the 1W (0.9W), to achieve the lowest in South Asia; 6 service: three months, shifting, one year warranty, three-year maintenance-free (the cost of materials discretion); (c) the types of certificates 1. military information security products Certificate (Jun 0413 secret literate No.) 2. Ministry of Public Security and Police Electronic Product Quality Testing Center certificate of inspection reports (No. 030 265 No. of public prosecution in Beijing) 3 National Quality Supervision, Inspection and explosion-proof electrical center of explosion-proof certificate (CNEx03.753) For the normal minor and mid-sized meeting room, it is easier to select the position of cell phone jammer and the needed position is less. 4, the State Secrecy Bureau emission of electromagnetic leakage protection products testing center certificate (TTCSSA2005YM23) (d) of Product 1, Product BH-201B (intelligent ultra-thin) BH-201B (intelligent ultra-thin) BH intelligent ultra-thin -201B phone signal blockers interfere with ultra-high bandwidth technology, intelligent remote control switch. Four-channel can be independently adjusted shielding range, interference radius, effective segmentation, only the downlink interference will not cause interference to the base station.For the meeting room whose area is about 100-300 square meters, 1-2 small power cell phone jammerinstalled inside are enough to shield the whole meeting room. Imported components, soft-start circuit design to produce the ignition switch to prevent the phenomenon of mechanical work and good stability.

This design will interest technicians who work on pneumatically operated valves and other 4-20mA current loop controlled devices. Although 4-20mA signal injector/calibrators are available, this one is both cheap to build and easy to operate. When first powered up, the circuit sinks 4mA of current. If switch S1 is pressed, the current level slowly ramps up to 20mA, pauses and then ramps back to 4mA.

This cycle will continue unless the switch is pressed again, whereby the output will lock to its current level. A further push of the switch resumes the prior cyclic operation. Output2 from the micro (IC1) is programmed to generate a pulse-width modulated (PWM) signal to drive the current sink transistor (Q1).

Circuit diagram:
 

The digital PWM signal is converted to an analog voltage using a low-pass filter formed by the 1kω series resistor and a 4.7μF tantalum capacitor. By varying the PWM duty cycle and therefore the DC signal level out of the filter, the program can indirectly vary the current flow through the transistor. A 100 resistor in series with the emitter of Q1 converts the loop current to a small voltage, which is fed into the micro on input1.

The program uses this feedback signal to zero in on the desired current level with the aid of the micros analog-to-digital converter. Details of this can be seen in the accompanying program listing. If the PICAXE senses an open circuit, it shuts down the output and goes into an alarm state, to alert the operator and protect the circuit under test. The switch can be pressed to reset operations to the start once the open circuit has been rectified.

The LED flashes a code for various milestones, as follows: one flash at 4m and one flash to confirm a switch press two flashes at 12m when ramping up (for the first 5 cycles); three flashes at 20m and continued fast flash sequence for open-circuit alarm. For portable use, the circuit can be powered from two 9V batteries, whereas for bench testing, a 12V DC plugpack will suffice.