Transformerless power supplies from 230Vac

Status
Not open for further replies.
R

ruggine

Junior Member level 3
Joined
Nov 29, 2002
Messages
27
Helped
0
Reputation
0
Reaction score
1
Trophy points
1,281
Activity points
117
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
 

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
 

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
 

transformer less

Hi all

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


S 8O KRAT
 

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.
 

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?
 

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.
 

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

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

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…