PORTABLE STREET LIGHT USING 555 TIMER

Hi friends you have already seen how to make street light using 555 timer in my earlier post here i will give you an idea to make a the street light for your school or college project or you can use it at your own home.See the following picture of my new model of the street light circuit,here i have used the texas instruments cmos version of 555 timer IC.I have used the same original circuit of street light which i have used in my earlier post but here I have fixed the power supply circuit and 555 timer circuit and the LED on a cardboard. 

 Now all the circuit description is shown in my earlier posts about the power supplies and bridge rectifier ,etc. are given in my earlier posts.I have used here a 220 volt to 9-0-9 volt transformer with 500 mA current.I have used the plastic sheet which come with cellular SIM cards to mount the LED.A Full wave rectifier is used in the circuit to convert AC into DC voltage and added a 100 Uf capacitor in parallel to the circuit to filter the ripples in the rectified AC or fluctuating DC Obtained from full wave rectifier.

A full wave rectifier  contains two diodes with a p or n junction sorted and other two ends open thus we get three terminals the sorted terminal is taken as output  and in this a three output terminal transformer is used such as 9-0-9 volt transformer The middle terminal is left as it is and the other two terminals are connected to the two terminals of the diodes the output is taken across the middle terminal and the sorted terminal of the two diodes.

As such the AC is rectified or converted into DC voltage which is of fluctuating nature,that is its value changes from zero volt to maximum voltage.It can damage the IC and may be the IC Shall not work.See the following diagram

Here you will notice the output waveform of the Full Wave rectifier.Its working principal is very easy in this when positive cycle comes in the transformer the A terminal is positive & C is negative and Cis positive & B is negative.So,in positive Cycle diode D1 is on and diode D2 is off so the current flows as A to C.Now in negative Cycle Of AC the B terminal is positive & Cis negative and C is positive & A is negative.so,the diode D2 is on and diode D1 is off  hence current flows from B to C.That is the current is flowing always towards C.Hence we obtain here the DC voltage.To remove the Ripples in the DC output we need a filter to by pass AC and allow DC to Pass.Capacitor is such a device,Which bypasses all the AC and allow DC to pass through the output terminals.The capacitor is always connected in parallel to the DC output of the rectifier.It value depends upon the frequency of the AC in the supply.Hence we obtain the Rectified DC Power Supply for our circuit.

I have connected the circuit voltage terminals to the supply voltage through a protective LED (green).It is connected in series to the suppy terminals of the circuit to protect IC from being Burned.

The LED will protect the CMOS 555 timer IC from burning hazards.Now There is extra terminals for the LEDs to Be Lighted.Here i have connected LED on an extra PCB for making It portable.You can use Ports to connect the LEDs. Also You can easily Light a Bulb using the Driver circuit will be explained later in new post.

Here are some snapshots

  Here is Video---