Electronics > Projects, Designs, and Technical Stuff
555 inverter brightness and over current issue
dave_j_fan:
probably smaller core getting saturated , i will adapt to PNP NPN design
http://pindiagram.blogspot.com/2012/02/dc-to-ac-inverter.html
NiHaoMike:
--- Quote from: dave_j_fan on December 01, 2019, 11:08:13 am ---UC3525A not an option, cost issue
--- End quote ---
How about TL494?
Zero999:
--- Quote from: dave_j_fan on December 01, 2019, 12:27:24 pm ---probably smaller core getting saturated , i will adapt to PNP NPN design
http://pindiagram.blogspot.com/2012/02/dc-to-ac-inverter.html
--- End quote ---
That design is very inefficient due to the huge losses with the 555 driving emitter followers.
If you use the original design posted at the start of the thread, with a centre tapped transforer two MOSFETs, the core is less likely to be saturated, since it will be alternately magnetised with opposite polarities, thus be used more efficiently.
If you need a smaller solution forget the bulky, inefficient inverter. Use a 12V LED and a small, lightweight, efficient boost converter.
dave_j_fan:
--- Quote from: Zero999 on December 01, 2019, 01:54:22 pm ---
--- Quote from: dave_j_fan on December 01, 2019, 12:27:24 pm ---probably smaller core getting saturated , i will adapt to PNP NPN design
http://pindiagram.blogspot.com/2012/02/dc-to-ac-inverter.html
--- End quote ---
That design is very inefficient due to the huge losses with the 555 driving emitter followers.
If you use the original design posted at the start of the thread, with a centre tapped transforer two MOSFETs, the core is less likely to be saturated, since it will be alternately magnetised with opposite polarities, thus be used more efficiently.
If you need a smaller solution forget the bulky, inefficient inverter. Use a 12V LED and a small, lightweight, efficient boost converter.
--- End quote ---
yes the core saturation was the issue
--its resloved! ---
8) 8) 8)
-- used Centertapped transformer and dual mosfets
-- Achieved good brightness at 230mA
so 2200mAH pack will last 8-10hour
with 2S4P we can get 20hour backup , which is huge
developed an ECO mode , slight less brightness at 155mA
on 2200mA ECO mode can pull till 12Long hours
All this with palm sized inverter.
test shown a 500mA transformer can take two 7Wbulbs ( lower brightness )
but this centertap is very good for one 7W
dave_j_fan:
Will the LOGIC mosfets give even better brightness ?
AC was approx 185V and the bulbs for 220V do very well now
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