Electronic drive fluorescents
 

On 25 Sep, 11:49, (Andrew Gabriel) wrote:
In article ,
* * * * robgraham writes:



I got two of these (why didn't I get a spare ?) out of a skip some
years back (~2000).

One of them works fine but the other is an unwilling starter - switch
on/flash/switch off/ wait for a count of 8/repeat about 6 times for
light to start.

I tried changing the tubes around - no change. *I put the bad one up
in the new workshop when it was initially wind and water tight, and
decided yesterday that it was time to change them over. *I came to the
conclusion it was easier to change the modules rather than the whole
light, and the fault follows the modules.

I've got a basic concept of how these things work ( I am an
electronics engineer), but does anyone know what the starting
circuitry is likely to be like so that I can try and trace down the
faulty component? *The electronics is all discrete components

Not going to be able to advise on repair over usenet, except
a common problem with ballasts of that age is arcing between
PCB traces, which is caused by poor washing of the PCB during
manufacture resulting in eventual breakdown, combined with
the manufacturers being new to designing PCB's carrying 600V
pulses and laying the tracks too close together. You might be
able to fix by peeling off an affected track and replacing
with a soldered insulated wire. Other than that, if there's
no obvious damage, you'll have to fire it up with the PCB on
a electronics workbench and try to spot arcing on the board
or inside any components. Needless to say, these have
dangerous voltages inside (significantly worse than mains),
and may remain dangerous a long time after switch-off.

However, I suggest you get a new electronic ballast. Basic
single tube non-dimmable are usually under £10 on eBay.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

You're right, Andrew - apart from the challenge of sorting it and it's
going to be a suspect cap I reckon, Ebay looks to be my friend.

This is a twin 70W tube fitting, and I can get a "Philips 2 X TL-D 70
WATT..TWIN BALLAST..WARM START" for effectively pennies. Internet
seems to suggest that TL-D tubes are something special, and what does
'Warm Start' mean?

Any guidance ?

Thanks all
Rob

Electronic drive fluorescents
 

In article ,
Rob G writes:
On 25 Sep, 11:49, (Andrew Gabriel) wrote:

Not going to be able to advise on repair over usenet, except
a common problem with ballasts of that age is arcing between
PCB traces, which is caused by poor washing of the PCB during
manufacture resulting in eventual breakdown, combined with
the manufacturers being new to designing PCB's carrying 600V
pulses and laying the tracks too close together. You might be
able to fix by peeling off an affected track and replacing
with a soldered insulated wire. Other than that, if there's
no obvious damage, you'll have to fire it up with the PCB on
a electronics workbench and try to spot arcing on the board
or inside any components. Needless to say, these have
dangerous voltages inside (significantly worse than mains),
and may remain dangerous a long time after switch-off.

However, I suggest you get a new electronic ballast. Basic
single tube non-dimmable are usually under £10 on eBay.

You're right, Andrew - apart from the challenge of sorting it and it's
going to be a suspect cap I reckon, Ebay looks to be my friend.
This is a twin 70W tube fitting, and I can get a "Philips 2 X TL-D 70
WATT..TWIN BALLAST..WARM START" for effectively pennies. Internet
seems to suggest that TL-D tubes are something special, and what does

TL-D is a bog standard tube (I think it stands for Tube Linear,
Double-ended), 6' in the case of a 70W one.

'Warm Start' mean?

It will preheat the electrodes for a second or so before trying
to start the tube. (Gives longer tube life unless the tubes are
operated for more than 3 hours each time they're switched on,
in which case it's no advantage over instant start.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Electronic drive fluorescents
 

On 25 Sep, 17:22, (Andrew Gabriel) wrote:
In article ,
* * * * Rob G writes:



On 25 Sep, 11:49, (Andrew Gabriel) wrote:

Not going to be able to advise on repair over usenet, except
a common problem with ballasts of that age is arcing between
PCB traces, which is caused by poor washing of the PCB during
manufacture resulting in eventual breakdown, combined with
the manufacturers being new to designing PCB's carrying 600V
pulses and laying the tracks too close together. You might be
able to fix by peeling off an affected track and replacing
with a soldered insulated wire. Other than that, if there's
no obvious damage, you'll have to fire it up with the PCB on
a electronics workbench and try to spot arcing on the board
or inside any components. Needless to say, these have
dangerous voltages inside (significantly worse than mains),
and may remain dangerous a long time after switch-off.

However, I suggest you get a new electronic ballast. Basic
single tube non-dimmable are usually under £10 on eBay.

You're right, Andrew - apart from the challenge of sorting it and it's
going to be *a suspect cap I reckon, Ebay looks to be my friend.
This is a twin 70W tube fitting, and I can get a "Philips 2 X TL-D *70
WATT..TWIN BALLAST..WARM START" for effectively pennies. *Internet
seems to suggest that TL-D tubes are something special, and what does

TL-D is a bog standard tube (I think it stands for Tube Linear,
Double-ended), 6' in the case of a 70W one.

'Warm Start' mean?

It will preheat the electrodes for a second or so before trying
to start the tube. (Gives longer tube life unless the tubes are
operated for more than 3 hours each time they're switched on,
in which case it's no advantage over instant start.)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Many thanks Andrew - all I need to know. Off now to Ebay !

Rob