1283Views4Replies

Author Options:

How to Speed up/ slow down of 230V LED alarm clock? Answered

LED clocks in the UK keep accurate time. When I bring them to Chennai, India, they lose time. The clocks are 230V 50Hz. In India the AC supply is supposed to be 50Hz. I tried a clock from Singapore hoping it would keep the time. It works OK in Singapore and not in India! I guess the frequency of the AC current is not correct. I know a bit of soldering and very very basic knowledge about electrical components. Is it possible to correct the time by adding a resistor or a capacitor to the circuit? Alternatively is there anything else I can do to make these clocks work correctly? Thank you in anticipation.

4 Replies

user
jasen (author)2009-07-13

Those clocs are based around chips that need a 50Hz (or 60Hz) AC supply to function.

an online UPS wth 50Hz output could help, but is not a cheap solution

Most LED alarm clocks have the chip LM8560N in them which does the
cycle counting, keeps the time and drives the display. you could download the data sheet from sanyo and see if you can see a way to make it work. without the right AC supplies.

Select as Best AnswerUndo Best Answer

user
Wesley666 (author)2009-05-21

No, India runs off 220-240vac single phase at 50Hz. You may want to buy a clock from India and try that and check that your other clocks work when you get home. If the clocks are fine and the clocks from India do the same thing you should take an oscilloscope to a plug and check what the frequency is.

Select as Best AnswerUndo Best Answer

user
11010010110 (author)2009-02-23

use a clock that keeps time with its internal cicuit\ all (or the very very most) modern digital clocks are ok clocks labeled 'quartz' (both analog and digital) are ok

Select as Best AnswerUndo Best Answer

user
S1L3N7 SWAT (author)2009-02-22

That's strange. Have you tried buying an alarm clock in India?

Select as Best AnswerUndo Best Answer