-/+ 50 v SMPS

[jash2008]

Originally Posted by FELIBAR12

A lot of questions:
#Turns?
primary?
Secondary?
Etdxx?
awg?
tl494? or sg3525?

#Turns? Primary 25T 1X18#, Sec 14T 2X20# for +/- 75V~
Etdxx? EE42/42/20
tl494? or sg3525? SG 3525 + IR2110

Thanks

[jash2008]

Hi everybody,
I am not much expertise with SMPS. I have few questions:

1. Transformer data: 25T Primary, 14 T secondary on EE/42/42/20 core.
2. Zener used 62V between 0V & + secondary voltage.
3. rest is same as mahmood schematic.

Now according to mahmoods revised schematic, the volts per turn comes to be 4.666 ( 42/9T). So the 14T in secondary should give ~65V and therefore I put 62V zener.

But my SMPS is giving +/- 78volts and this drops to Around 76 volts on connecting a 1000W halogen. Thus the SMPS is regulating the load.

Why this is happening. I think the volts per turn is incorrectly mentioned as +/-42 in place of +/-50 in the revised schematic. because if we consider 50 volts out from 9 turns, we get 5.555 volts per turn (50/9T) and this gives 78 volts for 14T.

Even if we consider 5.55 V/T, second question: why the SMPS is regulating 78 volts when the zener is 62 Volts.

Please correct If I am wrong anywhere .

Eva, could you please throw some light?

Thanks

[jash2008]

Few actual photographs of the two prototypes

[jash2008]

Originally Posted by Eva

The negative output rail is not connected to the diodes properly either.

Hi EVA,

Will this schematic work. Please suggest no. of turns and wire guage for the driver transformer. This is a combination of mahmoods schematic & C Audio pulse series SMPS

Thanks

[jash2008]

Hi EVA,

c audio schematic

[sivan_and]

Ur driving the MOSFETS as if they r transistors in this case IGBT

[savu]

better use an IR 2110, it is stable and reliable

best regards,

[microsim444]

Originally Posted by savu

better use an IR 2110, it is stable and reliable

best regards,

You tried that chip before?

[savu]

Originally Posted by microsim444

You tried that chip before?

yes and it is quite stable.
the only problem is that you can't use it to paralel mosfets because it can drive max 2A.

best regards,

[microsim444]

Originally Posted by savu

yes and it is quite stable.
the only problem is that you can't use it to paralel mosfets because it can drive max 2A.

best regards,

Correct