Blagdon Powersafe Help Needed

[wingcoder]

Hi All,
I have a 4 way Blagdon Powersafe and 2 of the green neons have blown. I am buying what I believe are the equivalent from e-bay to fit, however the instructions indicate that a 470K ohm resistor should be put inline in the bulb leg when used with a 240v supply.
Is this required in the Blagdon PS. There are several resistors on the PCB already which may already be doing this job.
I can't contact Blagdon, (Interpet) to get help, all I get is an automatically generated fob off e-mail so I'm hoping someone can give me some advice.

Cheers. G

 

[securespark]

Have you tried this email address?

[email protected]

Companies sometimes send an initial email saying they will get in touch within a certain time period.

 

[Spark123]

Can you provide a link to the ebay item?
Also some photos of what you have already may help including photos of where the neons connect in the circuit.

 

[ban-all-sheds]

Are there 4 x 470KΩ resistors on the circuit board?

If so can't you trace where they are connected to see if they are the resistors for the neons?

Do the failed neons which you've taken out have resistors in their packages?

 

[wingcoder]

Have you tried this email address?

[email protected]

Companies sometimes send an initial email saying they will get in touch within a certain time period.

Hi Securespark,

That was the e-mail address the message went to and basically it said that if the product was out of warranty there was nothing they could do and to go back to the supplier. Can't say I was that impressed.

 

[wingcoder]

Can you provide a link to the ebay item?
Also some photos of what you have already may help including photos of where the neons connect in the circuit.

Thanks for your reply Spark123. The item number is 120905997493 and I've already purchased them. They look like they may be slightly too big but I'll just have to leave the support cover off, once they're soldered in they should be able to stand up for themselves.
Regarding photo's, I'll see what I can do.
G

 

[wingcoder]

Are there 4 x 470KΩ resistors on the circuit board?

If so can't you trace where they are connected to see if they are the resistors for the neons?

Do the failed neons which you've taken out have resistors in their packages?

Hi Ban-all-sheds, There are resistors inline to the 240v mains side of the neons but I think they were about 1.64K ohm, (I did check the colour codes but I can't remember exactly what they were). Whatever; they were relatively low resistor values. There were no resistors soldered inline in the legs and no info on the neons themselves.

G

 

[Spark123]

1.64K seems like an odd size, what are the colour bands on the resistors?
Failing that, can you measure the resistance of one with a multimeter?

You may need to replace them with 470K versions (yellow, violet, yellow) but until we know what is going on with piccys is impossible to say.

 

[ban-all-sheds]

1.64K seems like an odd size,

It's in the E192 series.

I agree - odd.

what are the colour bands on the resistors?

Brown Blue Yellow Brown + a tolerance band.

You may need to replace them with 470K versions (yellow, violet, yellow) but until we know what is going on with piccys is impossible to say.

If all you can get is generic neons, add your own 470K resistor in series with one leg and see what happens.

 

[wingcoder]

Hi Guys, I was wrong on the size, as I said I couldn't remember the colours yesterday so I checked last night and they were, Brown, Brown, Black, Orange with a tolerance band of Brown, and I make that 110K, still much lower than 470K. Although, as there's two (R3-1 an R3'-1) that makes the overall resistance 220K, much nearer to 470K.

I've attached pics of the circuit board but as I've now received the neons from e-bay, (4 in case I blow some up ) I will probably give it a go and see what happens.

G

Images have been added, but they can't be seen in this reply? I've not done this before so I don't know if they should be seen. Come back to me if you can't access them, preferably with instructions, and I'll try to sort it out.

 

[maltaron]

Deleted

 

[stillp]

Are you sure they're neons, not LEDs?

 

[Spark123]

Just copy the bbcode from your album into your post to display the pics:

Top View of PCB

• wingcoder
• 2 Aug 2012
• 1

Bottom View of PCB

• wingcoder
• 2 Aug 2012
• 1

R3-1 and R3'-1 connect to Neon

• wingcoder
• 2 Aug 2012
• 1

I take it there are two indicators in there - one which says a channel is switched off and one to say it is on?
As the recommendation is to have a 470K resistor I'd be tempted to change one of the 110K ones for a 470K and replace the other 110K resistor with a link.

 

[ban-all-sheds]

What does it do that ordinary dumb mechanical switches don't?

 

[wingcoder]

Thanks for the help guys,
I don't think it does anything that dumb mechanical switches don't. It's just compact and waterproof. They are definitely two neons. Changing one of the resistors to 470k and linking the other one sounds like a good idea and is probably easier than putting a 250k online with a leg.
G