Transformerless power supplies from 230Vac

[ruggine]

mitedu.freeserve.co.uk/circuits/power/tps.htm

I would like to realize an application with microcontroller to 230AC of small dimensions, I would like not to use the transformer.
does someone know of the integrated able to realize small power supplies (no isolated, low power) directly from the 230AC?
thanks

 

[bomba]

Re: power supplies from 230ac

you can rectifier 230vac, make resistor divisor to aprox 15Volt, next can you use a 7805 or zener, you must to take care with the power in the resistive divisor, and with the consuption of the system.
I think that is a practical maner.....I don`t known is that the best manner

 

[C-Man]

Re: power supplies from 230ac

Maybe this can help you:
www.st.com/stonline/books/pdf/docs/8313.pdf

But you should be very careful as this supply is not isolated from mains.

If you need external components for your microcontroller (switches, inpu terminals etc.) that could be touched I would recommend the classical solution with a transformer for safety reasons.

best regards

 

[sokrat]

transformer less

Hi all

this circuit to convert 220 vlot to ~5 volt without transformer using Proteus 6 sp5


S 8O KRAT

 

[flatulent]

safety

These transformerless circuits are a serious safety problem. To comply with the safety laws, you will have to have the controller and all other circuitry enclosed in two independent layers of insulating material. Otherwise, a person could become part of a series circuit with the power mains.

 

[Al Farouk]

Re: transformer less

This application note from Microchip desbcribes the component calculation:
TB008 Transformerless Power Supply: www.microchip.com/download/appnote/pic16/91008b.pdf

 

[DrShoe]

Re: transformer less

The microchip application works perfect with +5V only. But the double version (need -12 +12 +5V) the capacitors 330u are getting warm.
How is this possible?

 

[Al Farouk]

Re: transformer less

Dear DrShoe
check the voltage applied to the capacitor and compare it to its rating. review the application note that posted previously and calculate the current through the main capacitor and the output voltage from the circuit.

 

[ME]

Transformerless Power Supply:
www.mitedu.freeserve.co.uk/Circuits/Power/tps.htm
www.aaroncake.net/circuits/supply5.htm
www.epanorama.net/links/psu_notransformer.html

 

[Testone]

I hope someone can state his experience in development of transformerless products

 

[Eternauta]

Also SUPERTEX hxxp://www.supertex.com/products/selector_guides
is selling HV linear regulator other than ST