running a bulb off 220 V

Discussion in 'The Projects Forum' started by KMK, Nov 9, 2010.

  1. KMK

    Thread Starter Active Member

    Feb 11, 2010
    Hello people
    i plan to makea regular 230 V light bulb blink using a 555 timer & relay.the frequency would be abt 30-60 seconds..
    wanted to know that since i will be using a relay for the bulb & also considering the frequency, should there be any capacitor or RC circuit to ensure long life of the bulb..
    Also i have a central tap trasnformer whith rating 9-09 V.. so what is the total voltage of the transfomer.. & is it possible to create dc supply with + & - voltages using the transformer ?
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    Dont understand the transformer rating you gave. What is it from?
  3. Artikbot


    Nov 7, 2010
    I'd suggest getting a regular wall transformer to power the oscillating circuit, those with regulable output.

    Why? Because they're cheap, low power and they already give DC, no need to transform and then rectify mains AC ;)

    There should be no problem using the 555 timer as long as you protect the output from mains (a relay seems a good idea, but be careful with the coil's inductance, remember that when coils are shutted off, they dump their stored energy into what's nearest (in this case your NE555) and it will probably burn it (spikes with 12V can be of about a hundred volts if no adequate dampening is used). With adequate protection (reverse biased diode?) it should be okay.
  4. KMK

    Thread Starter Active Member

    Feb 11, 2010
    thansk for that info artikbot.. the relay im using is a 6V relay.. so plan to use6v supply for the relay..& works fine..
    The transformer i mentioned is 230V converter.. i plan to make a +9/- voltage supply from it.. & use it for an opamp circuit using IC741.. so will i be able ot use it for that..