Simple Phone Tap Circuit.

This circuit is extremely simple, therefore there is less chance of any problems. It can be placed anywhere on the phone line and it will record any conversation on any phone on that line.
   
Part                         Total Qty.              Description

R1                            1                    470 Ohm 1/4 Watt Resistor   
R2                            1                    1K 1/4 Watt Resistor   
R3                            1                     100K 1/4 Watt Resistor   
R4                            1                    6K 1/4 Watt Resistor   
C1, C2                     2                    0.01 uF 100V Ceramic Capacitor   
K1                            1                    24VDC Reed Relay   
MISC                       1                    Wire, Headphone Plugs, Phone Plug Or Alligator Clips   

Electronics Circuit Application

Please note: I have received several emails saying that this circuit will not work and that it may hold your line off hook and to me it looks like it will (it would put quite a load on the phone line). For some, it has worked fine. Build at your own risk.

Colour (Sound) Organ Circuits.

 
                                                 circuit

Nokia N91 Phone white display Solution.

Nokia n91 is s very nice mobile phone but some time its create a different problem with display or LCD.Some time when you mobile on its not show the any display on the lcd or LCD show white.If its show the display blank(no lights and no display) so its mean your mobile phones LCD is damage then you open the mobile phone with mobile phone tools and replace the LCD.If its show the only white  and no display then may be your mobile Phone LCD is OK but display IC is damage.So replace the LCD with new one.If your mobile phone problem not solved then you then you replace the display ic.Display Ic i show you below picture.
These problem is same
Nokia n91 blank display .
 Nokia n91display problem.
 Nokia n91 display jumper.
 Nokia n91 no display.
 Nokia n91 white display.
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Electronics Circuit Application

 

China mobile GSM phone white display solution

Welcome to the mobile phone repairing tips blog.This is my farts  post on blog.my name is Rizwan Naz and i am a mobile repairing expert.My blog is all about the mobile phone;s software and hardware solution.Whenever you will visit my blog you will find the all solution of your any kind of cell phone.Here you can find all the cell phone repairing tips,applications,software,blackberry software information,nokia  mobile phone all models china all models solution.Today china mobile phone is very famous around the world but some time it create a problem white screen.It held after few second and became white display.There tow reason first your mobile phone put down on the floor and second your mobile phone water damage.
china mobile have many models but hardware have same software different.This picture have a one china mobile phone bored and seven IC;s same IC small and three main IC big and big one UUP IC and second REM thread is power IC.

Electronics Circuit Application

If you china mobile phone create a problem white display.
First of all you open a mobile with sample  mobile phone tools and put the mobile phone bored same  this picture and rehot the UUP IC.Then your china mobile phone problem 100% solve.
If you like my blog and you want to know about the cell phone repairing tips.please give me your comments. Electronics Circuit Application

Dark Activated Switch Circuits

 

Dark Activated Switch  Circuits

555 Timer Circuits

    
The 555, in fig. 1 and fig. 2 above, come in two packages, either the round metal-can called the 'T' package or the more familiar 8-pin DIP 'V' package. About 20-years ago the metal-can type was pretty much the standard (SE/NE types). The 556 timer is a dual 555 version and comes in a 14-pin DIP package, the 558 is a quad version with four 555's also in a 14 pin DIP case.




I nside the 555 timer, at fig. 3, are the equivalent of over 20 transistors, 15 resistors, and 2 diodes, depending of the manufacturer. The equivalent circuit, in block diagram, providing the functions of control, triggering, level sensing or comparison, discharge, and power output. Some of the more attractive features of the 555 timer are: Supply voltage between 4.5 and 18 volt, supply current 3 to 6 mA, and a Rise/Fall time of 100 nSec. It can also withstand quite a bit of abuse.

The Threshold current determine the maximum value of Ra + Rb. For 15 volt operation the maximum total resistance for R (Ra +Rb) is 20 Mega-ohm.

Alarm Circuit for 5 Zone Alarm system

5 Zone Alarm Circuit
My advice is to print off a copy of the schematic then to systematically list all components of one type. Start with resistors, write down their values from the schematic and place a pencil mark against the component on the schematic. Repeat until all components have been ticked. So reading from the schematic: