BOL News

BOL News

Online TV SHAH JEE PRODUCTION   August 24, 2015

Bol News TV Live - BOL, a new TV Channel is being launched soon. It will bring a revolution in media industry of Pakistan. The company is consisting of highly skilled professionals from all the regions of Pakistan. Currently, they are hiring new staff for their departments; Technical areas, Administration and Production. Bol Media Group has created thousands of employment opportunities by providing upgraded over 20,000 public transport across Pakistan. BOL is providing free repairs and an opportunity to vehicle owners to earn their living and elevate their quality of life. These vehicles are being upgraded free of cost with an ambition of revamping Pakistan’s public transport industry. It also provides the people of Pakistan a better travelling experience and an addition to the beauty of Pakistan. At BOL TV, we are working to become one of the leading channels of Pakistan, generating more than 50% of the revenues and profits of every global media market that we enter. At the same time we deploy our core competencies towards the socio-economic development of Pakistan. This is our mission and everything we do reflects this. Axact is well known name in the field of IT related products & services in Pakistan and it is serving IT industry since 1997 with full enthusiasm. It has global presence in 100 courtiers with 3.5 million customers worldwide. Axact offers significant contribution in the socio economic realm of Pakistan and now a new channel is coming up as a media revolution. Recently, Bol TV has hired its management and executive team which comprises of Nabeel as the President and CEO of Bol TV, media professional Faisal Aziz Khan joined Bol TV as the Senior Executive Vice President, reputed journalist Nasir Baig Chughtai as Senior Executive Vice President. Bol TV Network started off its journey with the extension in the professional workforce with some renowned names including Mr. Kamran Khan, Waseem Badami, Iftikhar Ahmad, Asma Shirazi, Muhammad Usama Ghazi, Nabeel Farooq Jakhura and Nadeem Raza along with many others. We are here to create better Pakistan through this Television Channel "BOL News TV". Bol News has started it's test transmission on 21st May 2015.

Monostable 555 Multivibrator Circuit

Monostable 555 Multivibrator Circuit

Electronics SHAH JEE PRODUCTION   August 02, 2015

Monostable 555 timer multivibrator circuit (one shot monostable multivibrator) is a retriggerable mono shot pulse generator. The name ‘Mono stable’ indicates that it has only one stable state. The unstable state is called ‘Quasi stable state’. The duration of stable state or the pulse width is determined by the charging time constant of the RC network. We can transfer the multivibrator from stable state to quasi stable state by using  push button trigger switch. The animated (simulated) working of the mono stable 555 multivibrator is shown in this article. You can use our monostable 555 timer calculator tool to find the duration of pulse(width) easily.

Components required

• IC 555
• Resistors (1MΩ, 100Ω)
• Capacitors (1µF, 0.001µF)
• LED Push button switch

Working of monostable multivibrator

• Output of monostable 555 multivibrator remains in its stable state until it gets a trigger.

• Primarily the transistor and capacitor are shorted to ground, this state is considered as the stable state of monostable 555 multivibrator.

• As we know, when the voltage at the second pin of 555 IC goes below 1/3 Vcc, the output becomes high. This high state is known as ‘Quasi stable state’. (Refer Astable multivibrator using NE 555)

• The trigger causes the transition from stable state to quasi stable state.

• So when we press the button (Trigger), the voltage at 2nd pin become less than 1/3 Vcc (disconnected from Vcc) and hence the output becomes high.

• Then the discharge transistor is cut off and capacitor starts charging towards Vcc (Refer the internal circuit below). Charging of capacitor is through the resistor R1 with a time constant R1C1. 

• As the capacitor voltage increases and finally exceeds 2/3 Vcc, it will reset the internal control flip flop, there by turning off the 555 timer IC (more than 2/3 voltage at the threshold pin (6th pin) causes IC to reset).

• Thus the output goes back to its stable state from Quasi stable state.