Rewind is perhaps the best option if you cannot find a suitable replacement.
You do want to check to make sure everything else is in good condition so that you are not needlessly reworking something that is otherwise servicable- many 25 cycle transformers were able to work on 60 cycles too.
I would just make sure the filter caps are good, and leaking excessively. Also making sure that the field coil is not partly shorted. This is just a bit of insurance, as the maount of work involved to check these is significantly less than that of rewinding power transformers.
: Does anyone know what is needed to convert a 25 hz
: power transformer to 60 hz. I have an old Westinghouse
: Mod. H-50 am radio that has a 25 hz. rating. When I
: run the unit for for a short time, the transformer
: gets very hot (and smells). Do I just have to rewind
: the transformer windings or what?
: THANKS for any help you can give!
In principle, all that would need to be done is to make a "divide by 2" circuit, make the needed changes to handle 120vac, and work from there.
The key would be the phasing of the trigger pulse to the corresponding rise or fall of the main supply current.
I have not seen anyone produce such a supply, but it would make for aninteresting construction project.
: Hi,
: The 25 Hz transformers use more copper and a bit more iron than the 60 cycle transformers.
: Rewind is perhaps the best option if you cannot find a suitable replacement.
: You do want to check to make sure everything else is in good condition so that you are not needlessly reworking something that is otherwise servicable- many 25 cycle transformers were able to work on 60 cycles too.
: I would just make sure the filter caps are good, and leaking excessively. Also making sure that the field coil is not partly shorted. This is just a bit of insurance, as the maount of work involved to check these is significantly less than that of rewinding power transformers.
: : Does anyone know what is needed to convert a 25 hz
: : power transformer to 60 hz. I have an old Westinghouse
: : Mod. H-50 am radio that has a 25 hz. rating. When I
: : run the unit for for a short time, the transformer
: : gets very hot (and smells). Do I just have to rewind
: : the transformer windings or what?
: : THANKS for any help you can give!
: In principle, all that would need to be done is to make a "divide by 2" circuit, make the needed changes to handle 120vac, and work from there.
: The key would be the phasing of the trigger pulse to the corresponding rise or fall of the main supply current.
: I have not seen anyone produce such a supply, but it would make for aninteresting construction project.
: : Hi,
: : The 25 Hz transformers use more copper and a bit more iron than the 60 cycle transformers.
: : Rewind is perhaps the best option if you cannot find a suitable replacement.
: : You do want to check to make sure everything else is in good condition so that you are not needlessly reworking something that is otherwise servicable- many 25 cycle transformers were able to work on 60 cycles too.
: : I would just make sure the filter caps are good, and leaking excessively. Also making sure that the field coil is not partly shorted. This is just a bit of insurance, as the maount of work involved to check these is significantly less than that of rewinding power transformers.
: : : Does anyone know what is needed to convert a 25 hz
: : : power transformer to 60 hz. I have an old Westinghouse
: : : Mod. H-50 am radio that has a 25 hz. rating. When I
: : : run the unit for for a short time, the transformer
: : : gets very hot (and smells). Do I just have to rewind
: : : the transformer windings or what?
: : : THANKS for any help you can give!
A CHEEP AND SLEEZY APPROACH MIGHT BE STICKING A DIODE IN THE SUPPLY 'LINE' SIDE THIS'LL PRODUCE A 30HZ HALF WAVE FROM THE 60HZ AT REDUCED LINE VOLTAGE, IT'D BE EASIER THAN REWINDING THAT BEAUTIFUL OLD 25Hz XFMR, TRY IT, YOU CAN'T HURT IT MORE THAN PLUGGING 60HZ INTO IT, IF THERE ISN'T ENOUGH VOLTS TRY RUNNING IT UP ON A VARIAC(BORROWED OR OTHERWISE) TILL IT WORKS OK, YOU MIGHT NEED A STEP-UP XFMR TO 170-200V TO MAKE IT WORK, THEN THE DIODE AFTER THE STEP UP. MOST METERS DON'T READ ACCURATELY ON 1/2 WAVE (LOW) SO KEEP TO THE LOWSIDE IF YOU'RE NOT SHURE
: Hi,
: It may be possible if you are willing to do some construction, to make a 60 Hz to 30 Hz converter. That should be a close enough frequency to work well for strictly 25 cycle transformers.
: In principle, all that would need to be done is to make a "divide by 2" circuit, make the needed changes to handle 120vac, and work from there.
: The key would be the phasing of the trigger pulse to the corresponding rise or fall of the main supply current.
: I have not seen anyone produce such a supply, but it would make for aninteresting construction project.
: : Hi,
: : The 25 Hz transformers use more copper and a bit more iron than the 60 cycle transformers.
: : Rewind is perhaps the best option if you cannot find a suitable replacement.
: : You do want to check to make sure everything else is in good condition so that you are not needlessly reworking something that is otherwise servicable- many 25 cycle transformers were able to work on 60 cycles too.
: : I would just make sure the filter caps are good, and leaking excessively. Also making sure that the field coil is not partly shorted. This is just a bit of insurance, as the maount of work involved to check these is significantly less than that of rewinding power transformers.
: : : Does anyone know what is needed to convert a 25 hz
: : : power transformer to 60 hz. I have an old Westinghouse
: : : Mod. H-50 am radio that has a 25 hz. rating. When I
: : : run the unit for for a short time, the transformer
: : : gets very hot (and smells). Do I just have to rewind
: : : the transformer windings or what?
: : : THANKS for any help you can give!
Ed.