15mA 120V AC Power supply dessign

[binspaul]

Hi,

Does anybody has a PCB schematic for the following power supply:

* Input voltage: 220V AC @ 50Hz
* Output voltage: 24/48/110V AC @ 50Hz.
* Output rating: 10mA to 20mA.

Are there any transformers available in this specification ?

Regards,
Bins.

 

[Bootstrapper]

Hi, there should be suitable transformers readily available meeting your specs. Just check the catalogs!

 

[binspaul]

Hi,

I was able to find some transformers in the required voltage ratings from the site: http://www.futureelectronics.com. But, the current ratings is around 50mA to 100mA, which is mush bigger than my required value. Is there any way to reduce the current to the required level of 10mA to 20mA ?

Thanks in advance,
Bins.

 

[Bootstrapper]

It's not bad at all to have a little extra current capability. You are building a voltage source now, and the load current will be determined by the load, not the source. So having a transformer with certain current value doesn't mean that the transformer will be sourcing that amount of current all the time!

You'll do fine with the transformer you found.

 

[binspaul]

Hi Bootstrapper,

As per your reply, I am planning to go for the transformer with the following ratings:

* Primary Voltage: 115V
* Secondary Voltage: 24 +/- 10V
* Secondary Current: 41mA
* Rated Power: 1VA

I have attached the motor specifications file below. It will be really helpful if you can advice on my decision. Do I need to choose a much higher value transformer available (like 63mA or more) ?

Thanks & regards,
Bins.