I have a tape recorder from US whose rectifier takes 30 volts 1amp which is realised using 120 volts 60 hz step down transformer. So I took an Asian Transformer Input 230 volts 50 hz and output is 30 volts 50 hz 1 amp. The transformer is getting heated and sometimes burn. What I have observed is if the tape is not running and just connected to the supply with switch on the socket point of the tape is very hot. Need help Thanks Anil Deshpande
and here lye the problem. did you measure to make sure 30 volts at the output of the rectifier is what you really should get? its possible the secondary is to high. you must remember that the voltage your getting is in RMS. after being rectified and filterd its going to be higher. the Peak is around 42 volts. you mite want to check this.
anil.deshpande wrote:
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Anil,
Secudary current of a transformer is usualy specified for continuous load i.e. a heater or a lamp. A rectifier is all but such a load. It only draws current peaks at the top of the sines of the voltage. So if you want to draw
1Adc from your bridge rectifier, your transformer should be able to provide at least 1.4Aac continuous current.petrus bitbyter
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Here lies the problem "Asian Transformer." The design of many replacement transformers from Asia allow a higher temperature rise, or use as little Iron as they can get away with without blowing a fuse. If you must use an Asian Transformer derate it by at least 50%. So for a 1 amp output get a transformer rated at 1.5 amperes minimum. 2 would be better. However it will still run very warm. Get a US or EU made transformer and there will be an obvious difference!
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