ray99mond

problem was solved... thanks

http://www.electronics-lab.com/projects/test/014/index.html i made a circuit like this and it works but how can i make the reading more stable because currently the reading is keep on fluctuating. thanks

i need it for AC line.. if possible, can include the value of the components for me ? thanks

Hi, sorry to asking a noob question, anyone have any idea or any circuit design for a input filter for a 240VAC? Thanks a lot

audioguru thanks a lot, I'll try again

is it add a resistor at the VDD pin 14 of CD4047? zener diode is placed parallel with the resistor ?

i got a problem here, i constructed such circuit and i am able to get a square wave output (without connecting to transformer yet), however once i connected to the transformer, the IC CD4047 burned. may i know what is the problem? or i really need to add a fuse there?

Hi audioguru, 1. how come the -TRG (pin6) of the CD4047 is not ground like +TRG (pin8)? 2. The output of the Q (pin10) & -Q (pin11) is a square wave right, then what is the function of LM358? square wave generator? 3. what is the function of 2SC1061 and 2N3055? 4. why connect 12VDC to the pin2 of the center tap transformer? Thanks

audioguru, do you have any pure sine wave 12V to 240V inverter ? Thanks

for backup computer for a short while only.. btw, the secondary transformer output is 240V, 240V x 2A = 480VA right? why time the 2A with the primary voltage; 12v ?

actually the transformer that i am using now is a 240V to 12V step down transformer for my rectifier circuit. I need this inverter for my UPS project, so this 500W inverter is suitable... so what kind of transformer i should get to support 500W output? 20A transformer?

I see... thanks for your explanation .. ;D btw I have a 3A step down transformer from 240VAC (primary) to 12v-0-12v (secondary) for the rectifier system, can i use it as the step up transformer for this circuit? 12v-0-12v become the primary side while the 240VAC as the secondary side?

the voltage will change with the load? the project is using 12v-0-12v to 220 transformer, so the circuit circuit should generate 12VAC at the primary side of the transformer right ? My problem is why i get 24VAC instead of 12VAC... Thanks

sorry for confusing, I built this 500W inverter but not yet connect the transformer to that circuit yet. and the 24VAC is come from the circuit which should be connected to the transformer. sorry for drawing it wrongly.

Thanks for your great reply I measured the voltage between "12V to 0" and i get 24VAC and same result for the "0 to 12V" I didn't connect to a transformer yet for safety purpose.... so is the reading correct ? or should be 12VAC instead of 24VAC?