These chinese decoration lights

Thread Starter

buddyengineers

Joined Mar 19, 2005
26
hello everyone,
U must have checked these chinese made decoration lights they have abt 50 LED's connected in series and a small controller with a volume adjust button. Wat i want to ask is tht how does the electronics within the controller manage to run on 230V AC,50Hz. Out of curiosity i opened one and found no transformer no rectifier just one Chip controlling pattern of LED's glowing and also theres coming from the speaker.
The size of the controller is abt say 7cmX5cm. Magic of electronics it seems to me

Post in if u hav any idea abt it.
thnx
Dilu
 

David Bridgen

Joined Feb 10, 2005
278
Originally posted by buddyengineers@Mar 19 2005, 07:50 PM
hello everyone,
U must have checked these chinese made decoration lights they have abt 50 LED's connected in series and a small controller with a volume adjust button. Wat i want to ask is tht how does the electronics within the controller manage to run on 230V AC,50Hz. Out of curiosity i opened one and found no transformer no rectifier just one Chip controlling pattern of LED's glowing and also theres coming from the speaker.
The size of the controller is abt say 7cmX5cm. Magic of electronics it seems to me

Post in if u hav any idea abt it.
thnx
Dilu
[post=6227]Quoted post[/post]​
If there is no transformer then there will be a capacitor in series with one of the mains wires, ideally one in series with each.
The value of the C, and therefore its reactance, will be such that it drops the voltage to a suitable value.

Rectification must take place somewhere. Perhaps it's in the chip.
 

Thread Starter

buddyengineers

Joined Mar 19, 2005
26
Originally posted by David Bridgen@Mar 20 2005, 12:58 AM
If there is no transformer then there will be a capacitor in series with one of the mains wires, ideally one in series with each.
The value of the C, and therefore its reactance, will be such that it drops the voltage to a suitable value.

Rectification must take place somewhere. Perhaps it's in the chip.
[post=6231]Quoted post[/post]​

thnx for the suggestion david, but if there must be capacitor, so as to handle 240VAC, it must be of a suitably large size, but i cant see any cap in the controller, also as i mentioned to u the size of the controller it definitely cant fit in it a cap to handle 230V.
Also to add to it the lights cost us barely 50 UScents thts about Rs. 30 here in India.

Still a mystery
thnx anyways
Dilu
 
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