bulb question

[jamie123]

i need to buy a replacement bulb,the original is a grain of wheat type,6v 35ma.
im having trouble buying a same spec bulb,i can get 6v but a lot are 60ma rating,can someone explain what the difference would be and if it will be ok to use ?
thanks.

 

[redk9258]

I would not use a 60mA in place of 35mA. The current is almost double. The heat will almost double. If mounted in / around plastic, might melt. The brightness will be too bright. It might be bad for what ever drives it, for example an unobtainum IC.

What is the bulb for?

 

[jamie123]

hi its for a sony turntable,its the bulb that lights the 33rpm speed indicator,the closest ive found is either 6v 40ma or 16v 35ma

 

[redk9258]

http://www.ceitron.com/cart/product_info.php?products_id=8306

Several are listed on eBay. Search "6 Volt 35mA lamp"

 

[triode17]

the closest ive found is either 6v 40ma or 16v 35ma

6v at 40 ma isn't bad. That's just 14% more power taken. But do check that it won't burn anything nearby.

 

[jamie123]

Would a 12v 35ma be better?

 

[gadget73]

I expect it would be fairly dim since its at half it's intended working voltage. Won't make much heat though.

Can you add a resistor and convert to LED ?

 

[jamie123]

I could but I wouldn’t have a clue what resistor I’d need etc, I’ll see how the new bulbs look first .

 

[jamie123]

well my bulbs arrived in the week so today i soldered in a replacement,i now have 33rpm illuminated again,phew! whilst i was in there i cleaned and lubricated all the speed potentiometers.

 

[redk9258]

So what bulb did you actually end up using?

 

[jamie123]

I actually sourced the right spec bulb, 6v35
Ma, when I put it in it was dimmer than the original so I used a 6v40ma which matched the brightness of the original, go figure!