Help! Why the flicker?

Page 2 of 2  
Harry Bloomfield wrote:

Ditto. I have some electronic ballasts in fluorescents that do this. Till they warm up.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 30/12/2003 Bill Gardener opined:-

One further point, are we discussing an actual transformer, either ferro or torroid cored? These will be quite heavy, about the weight of a house brick. The other possibility is a switch mode type, which ought to work at a much higher frequency than the 50Hz mains frequency. If a badly designed SMPSU, then it might give rise to the effect you are reporting. An SMPSU would be relatively light in weight.

It depends what you call series. With the 3 lamps in series they would each receive about 4v each (12v/3 = 4v) and would be very dim, so no.
--

Regards,
Harry (M1BYT) (Lap)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 30 Dec 2003 22:47:45 GMT, Harry Bloomfield wrote:

The image in the link previously posted looks like an electronic transformer aka a SMPS. Add in the 10 min delay then I suspect they are overheating and shutting down/becoming unstable.
Check the specification of the transformer, is it capable of driving 3 x 50W lamps. Yes, they maths is OK but practice is another matter...
It would also be fairly important that each transformer only feeds 3 lamps. The two transformer outputs are best completely isolated from each other.
--
Cheers snipped-for-privacy@howhill.com
Dave. pam is missing e-mail
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Bill Gardener wrote:

AH!. A steady flicker...that appears once the units are warm? Bet its a weird oscillation in the electronic transformers.
Ditch em and get some other ones.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Clutching at straws here but....you are running from two smpsu/transformer things. If you disconnect one then does the other continue to flicker in the same manner ?
I wonder if what you are seeing is some kind of beat frequency as the frequency of the 'transformer' output drifts as it warms up.
They could start of very close to being in phase with each other then drift at different rates.
I'll admit it seems unlikely, but you never know.
n
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I have three in-cupboard 20w LV halogen lights in my kitchen. The two connected to one electronic transformer (SMPSU) don't flicker; the third one, connected to its own transformer, does. The flicker is a random changing in brightness.
Swapping the transformers and bulbs over didn't cure it; the flicker stayed with the lone fitting and I put it down to the transformer being under-loaded and not regulating properly. Since it's only in-cupboard lighting, I haven't let the flicker worry me; it would be very irritating if it were in general room illumination though.
--
A. Top posters.
Q. What's the most annoying thing on Usenet?
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Took out one of the lamps from each set and the flicker stops. So although the transformer is rated at 150W and the lamps at 50W each. The transfomer can't cope with three lamps.
Bloody ridiculous.
Thanks for everybodies help,
Bill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Bill Gardener wrote:

Yep. On the limit stuff. I buy from Newey or another electrical distributor for this stuff. They don't stock total crap usually.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Was this an electronic type, Bill?
.andy
To email, substitute .nospam with .gl
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

although
transfomer
Yes
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

So presumably dropping out of regulation or some other funny effect, I'd be inclined to return it, since it shouldn't do this...... .andy
To email, substitute .nospam with .gl
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 31 Dec 2003 11:45:27 +0000, Bill Gardener wrote:

You might get away with replacing the 50W with 35W. IME there is a required derating for electronic 12V supplies of 30%. The figure is 0% for low tech Xformers, which can still be dimmed with the right type of dimmer.
--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.