Bathroom light flashing?

[morphe]

In my bathroom I have a circular fluorescent tube, I have replace the bulb and the starter switch, yet it stills flickers and eventually comes on, sometimes not. Just wondering, could it be the rectanguilar box(transformer)?

Any ideas chaps?

 

[breezer]

the rectangular box is a choke, "probably" cheaper to get new same light keep tube and starter, than going to electrical wholesalers getting choke, take old one out, fitting new one etc

 

[oilman]

Is there an earth connection to the fitting?

 

[securespark]

When I was green, I fitted a flu in the kitchen for my Ma. I had trouble getting the tube to strike, and discovered that I had not connected the cpc effectively (earth) When that was put right, the unit worked perfectly.

So, yes! Check the earth. Also worth trying another tube and starter in case they are dicky.

A faulty ballast (choke) usually means an open circuit on the coil (choke is basically a huge coil of wire) and no electricity leaving the choke and that means a dead fitting altogether.

If you can, try testing the choke output to see if 240 is getting through.

If so, I would try alternative tube & starter - if dead then replace fitting.

However, circular flu's these days are rare......Argos may have one, but my local wholesalers stopped stocking them years ago!

 

[breezer]

i would definently NOT recomend to see if there is 240 going through the choke (not unless you want to kill yourself)

yes a choke is a coil of wire but when you disconect from it the that is when you will get a very high voltage (couple of thousand)

what do you think the starter actually does, it is basically an automatic electric switch, it opens and closes causing the choke to generate a few thousand volts which can then go from one end to the other of the flourescent tube (or to strike) this high voltage is required to jump the distance from one end of the tue to the other, once it has struck the choke then limits the current

 

[securespark]

Breezer

Checking choke output with a multimeter or even neon driver is as safe as any other voltage test. The tube will be disconnected while you are doing the test, therefore there won't be high voltages present, but you will (if the choke is serviceable) get a reading on the output terminal. Without blowing yourself up. If you don't believe me I'll come round and show you. I've done it a few times and I'm still here.

 

[breezer]

just because you haven't had a big shock (yet) doesn't make it safe.

but let us agree to disagree on that one

 

[phil28]

after all that good advice given do try another stater and tube, but in the long run buy another light.