45 w 12v/7.5 ah inverter shows 650 vac

Status
Not open for further replies.
S

saminda

Newbie level 6
Joined
Jan 11, 2012
Messages
13
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Dombivli, India, India
Activity points
1,386
I have 45 w inverter .when I connected to mobile charger or any small instruments , charger's led lites up and gone off immediate.I have checked its output ,its huge 630vac and 227vdc .please help me I want to repair that at home
 

Dear saminda
Hi
Welcome to the EDA board .
How can i help you without the photo of your circuit? you just described a little about it's properties.
Best Wishes
Goldsmith
 
without a circuit diagram we can only make some intelligent guesses
as to what can be the problem and solution
 
Last edited:

saminda said:
I have 45 w inverter .when I connected to mobile charger or any small instruments , charger's led lites up and gone off immediate.I have checked its output ,its huge 630vac and 227vdc .please help me I want to repair that at home
Click to expand...

Hi Saminda,

Can you give us picture of circuit, that will help us to find problem.
 

One thing I can think of without the circuit diagram is that the output load is insufficient. You might need to alter the value of the output inductance - probably increase it quite a lot - in the step-up portion if a light load like this charger is going to be used all the time.

Hope this helps.
Tahmid.
 




sorry for late replying guys
i have uploaded some pictures .
It has 3524 smps controller and in smd packeged ic is 4050 non inv buffer,two p55nf60 mosfet.
please let me know what wrong in this ckt.
 

what is the value of transistor T12, whose bottom portion on the pcb solder side seems to be burnt?
 

What is the model number who made it ?
does it work from mains ? attach 220v 25watts lamp and check with this load . if bulb burnout u may have the dc 227 from input rectifier break-thru the output transformer isolation primary to secondary .
 

I doubt the output of the inverter is AC. From the pictures, I can tell that the output is DC. There's no high voltage full bridge section to convert the high voltage DC bus to 50Hz AC. This looks like an inverter for lighting CFLs.

A part of the PCB shows burns. You should check the components there. I think some part there is damaged, that's why you have malfunction.

Is T12 a transistor or is it an LM317 from the charging portion?

Hope this helps.
Tahmid.
 

t12 =c557,burnt comonent is regulator LM317.its working properly with 14v charging voltage.

it is local made.what will be the transformer's rating
 

saminda said:
t12 =c557,burnt comonent is regulator LM317.its working properly with 14v charging voltage.

it is local made.what will be the transformer's rating
Click to expand...

Which transformer are you talking about? The charging transformer? If so, a 15V 2A transformer will be good.

---------- Post added at 23:30 ---------- Previous post was at 23:29 ----------

Also, you should take note that, like I've said before, the output is NOT AC, but DC.
 

That's not an isolation transformer.

That's the step-up transformer used to convert the 12V to high voltage.

It's a ferrite core transformer that works like a normal 50Hz transformer when stepping-up or stepping-down voltage, but works at a much higher frequency. I think in this circuit it works at around or more than 30kHz.

It's probably wound for 12V to 320V or higher.

Hope this helps.
Tahmid.
 

so what should i check to run this ckt properly
do i have to change the step up transformer? if so what will be the rating
what else i should have to change or check????
please help
 

You tested this with small load (mobile charger). Before any more suggestions, you should connect the output to a 20W bulb and see if the bulb lights properly. Also, check the output DC voltage.
 

I have checked its output ,its huge 630vac and 227vdc .
Click to expand...
One important point here.
If you check dc voltage by mutimeter set to AC range, it will show double voltages.
If there is no DC component and out put is AC, no voltage is shown on meter set to DC range.
 

Your inverter must be having pulse output thats your dc reading of average 270v , as for ac your meter does not have true rms option it reads peak volts.
 

ALERTLINKS said:
One important point here.
If you check dc voltage by mutimeter set to AC range, it will show double voltages.
Click to expand...
Can you explain why this is so?
But if it is, then it's probably right. Since DC voltage should be around 300V.
And again I repeat: Output of this "inverter" is DC, not AC.

---------- Post added at 00:34 ---------- Previous post was at 00:31 ----------
dselec said:
as for ac your meter does not have true rms option it reads peak volts.
Click to expand...

I'm pretty sure the meter doesn't read peak volts, but possibly average volts.
When you measure the AC voltage using a standard AC voltmeter, it doesn't read 311V, rather, it reads 220V.
 

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…