Wiring panel

This is a circuit that will find application in the case where you have a lot of telephones installed on a telephone line and would want to know if somebody of them is open. Thus you will not be off any discussion. Simultaneously it can cut the certain sound from stereo amplifier that are in high volume, the sound of some television or turn on some light the night when it ring the telephone and needs him you raise. Here’s the figure of the circuit;

Exists a pair of free contacts of RL1 that connects to the J2, which you can use connecting there any appliance you want. The telephone line connected in the J1, with what polarity you wants. When the telephone is closed then the line voltage is roughly, 48-50Vdc. This voltage turn on the photo diode and this, the transistor of IC1, which it simultaneously isolates, the circuit from the telephone line. The photo transistor in IC1 are now in situation ON, the input of IC2A are LOW [L] and output HIGH [H]. Ignoring for little the circuit of delay D6, R4, R5, C1, the IC2B input, are also this HIGH hence the output are LOW, transistor Q1 are OFF and the RL1 are deactivate. When the telephone earphone is raised, then the telephone voltage line fall in 6-10Vdc.

All the previous situation is reversed also the RL1, turn on. The telephones that use for dial choice, disk or pulse system, can they open and close the RL1 at the duration of choice. With delay network, that exist between in gates IC2A and in the IC2B, we delay the situation changes in the input of IC2B, ensuring thus stability in the operation of RL1. If the R4=100K then the RL1 is activated when the telephone ring or when the earphone is raised. On the contrary if the R4=1M, then the RL1 is activated only when the earphone is raised. The circuit supply becomes with a simple regulation circuit, in + 12V.

Part:

R1-2=36Kohm
R3=100Kohm
R4=100Kohm or 1Mohm 
R5=2.2Mohm
R6=3.3Kohm
R7=1Kohm
D1....4=1N4002
D5=1N5252 [24V 0.5W Zener]
D6-7=1N4148
D8....11=1N4002
D12=Red Led 3 or 5mm
RL1=12Vdc 2X2 relay
J1-4=2pin connector 2.54mm step
J2=6pin connector 5mm step
J3=2pin connector 5mm step
F1=Fuse 500mA [5x20mm]
C1=100 or 220nF 100V MKT
C2=1000uF 25V
C3-4=100nF 100V
C5=4.7uF 16V
IC1=4N25 opto coupler
IC2=4011B
IC3=7812 [1A]
Q1=BD139 or BD679
T1=12Vac 500ma tranformer for pcb

Treatment LCD Monitor. At this time computer use familiar and already widely used either for work or entertainment. And of course when talking about computers it will not be far away with a device called a monitor. And today use CRT monitors have started to decrease with the LCD Monitor that despite having a price that is quite expensive but have many advantages than conventional CRT monitors.

Here are a few advantages of LCD monitor is a stylish design, flat screen and a brighter color than convex or crt monitor screen, while also LCD Monitors have many advantages among which have a high resolution so that it can help many people especially those working Visual design field.

There are some special treatment for LCD monitors in this case is for the treatment of LCD monitors, the following are some steps steps:

Use the LCD as needed, Do not use if you do not need so-necessary and do not use it 24 hours nonstop jedanya have no time for any electronic item there during his lifetime (Lifetime). Turn off your LCD monitor when your computer dies, in order to save electricity and also keeps your LCD monitor remain durable.

Use the type that has a grounding electrical power, because it can minimize the damage in the event of lightning strikes. This option is optional.

Perform regular cleaning, at least 2 weeks 1 times, for LCD monitors are always in a state clear of dust and other debris. Remember! to clean it must use a very soft cloth that has spread with a special liquid cleaners LCD monitor. If necessary you can buy special equipment to clean the LCD monitor.

Do not engage in cleanup activities in the state of electricity is still flowing, unplug all cables available on the LCD to avoid things that are not desired. The existence of water coming into the series of LCD monitors will be able to cause fatal damage.

Keep the LCD of the things that contain water such as rain water, drinking water etc.. Because all electronic goods electrical short circuit will occur if water enters into the electronic components.

Keep the LCD of goods containing such magnetic sound system, Persani, HP etc. signals. Because it will be fatal is going to happen Noise or damage which may destroy the layout on the monitor screen.

LCD Save a strategic place and safe from the reach of small children, so that you can not avoid tersenggol LCD or a small toy.

Unplug all cables associated with the computer (including LCD) in the event of rain accompanied by lightning, because lightning can be grabbed via the antenna propagate through the cable TV and electricity.

To protect the screen / LCD screen can use the Screen Protector function prevents dust entry into the LCD and also take care of all sorts of scrapes. Remember to choose the screen protector is not a trace when reopened.

If there is damage to your LCD monitors, LCD submit to the experts. Do not disassemble itself without accompanied by experts in the field of electronics. Module Components including LCD monitors that can be easily damaged. LCD Monitor Service you to the service center to ensure the improvement is good and right.

Good article on the LCD monitor is beneficial treatment.