need help to build my own smps based on blaupunkt schematics gta400 please

[Ground Zero]

I will buy parts here

Farnell France | composant électronique connecteur - distributeur de composants électroniques, composants électriques, connectique et fourniture industrielle - 500.000 références - livraison sous 24h.

I also need strap....

I finish to build the pcb, i'll proceed to drilling

An externally hosted image should be here but it was not working when we last tested it.

 

[Perry Babin]

There isn't much to chose from at that site. Although it may not look good, I'd suggest that you use the MPSA06 and MPSA56 as drivers. The pin configuration is different so you'll have to swap legs 2 and 3 when inserted into the board. If you can find more suitable transistors later, you can replace these. I know the A06/56 work well as drivers.

The drivers suggested earlier may be good substitutes but I haven't used them.

What process did you use to print the board?

 

[Ground Zero]

Thanks a lot for your help

For the driver may i use 2sa965 and 2sc2235 ?

to print the board, i use ferric chloride.

 

[Perry Babin]

What printing/transfer method?

Those should be OK as drivers.

 

[Ground Zero]

For transfer printig method i use a canon MP980 Ink jet with paper for overhead projector

Now i've drill all the pcb it was very long, for that i use a proxxon drill

 

[Ground Zero]

Hello

I've got news about my smps

For the moment i haven't reveive all component but i have bought all resistor in carbon with 1% tolerance and 1/2W

For the moment i build a new pcb will have five condensators nichicon Kw of 2200 µF 50V each for the input and six condensator nichicon kw of 10000 µf 50V each at output

Theses condensators are special for audio but are expensive

I will put pictures when i'll finish it

 

[Ground Zero]

this is a picture of the supply but i must finish it

An externally hosted image should be here but it was not working when we last tested it.

 

[Ground Zero]

When you build something like this, especially if you don't have much experience, you don't install all of the parts and then apply direct power. After you etch the board, install all of the jumpers, resistors and capacitors.

Connect it to a power supply as you normally would. Initially, use a 3 amp fuse to protect the components. Confirm that you have 12v on pins 8, 11 and 12 of the 494 and no other pins.

If that's OK, install the IC and see if it produces output pulses. If it does not, let us know. If it does produce pulses, confirm that you have clean a clean drive signal on the gate pads for all of the power supply FETs.

Do you have the transformer wound yet?

Hello

I have 12v volts on pins 8, 11, 12 of the tl494cn and no on other pins


I put le Ic and it's seems to work well but could you tell me please how to set the scope to see if it produce pulse ?

thanks

 

[Perry Babin]

Set the vertical amp to 5v/div. Set the timebase to 10uS. With all other settings as they were when you had it connected to the calibration point, you should see a square wave on pins 9 and 10.

 

[Ground Zero]

Thanks Perry

but i need to set the scope to Ac, or Dc ?

 

[Ground Zero]

i set the scope to ac with 5v/d and 10µs

I haven't clean square wave, it's like sinus wave parasitic

 

[Perry Babin]

AC or DC probably won't matter but set the scope to DC.

Post a photo of the waveform.

 

[Ground Zero]

Ok i set to Dc and this is the picture

An externally hosted image should be here but it was not working when we last tested it.

 

[Perry Babin]

Do you have your scope ground connected to your 12v power supply ground. If not, do that now.

Post a photo of the waveform on pin 5 for a reference.

 

[Ground Zero]

Ok i connect probe ground to ground supply and that's better

I have this for pin 9 and 10 with 5v/div and 10µS time base

An externally hosted image should be here but it was not working when we last tested it.

for pin 5 i have this

An externally hosted image should be here but it was not working when we last tested it.

 

[Perry Babin]

Set the vertical amp (v/div) so that the signal on pins 9 and 10 deflects approximately 3 major divisions (squares). At that point, the scope should lock onto the waveform.

 

[Ground Zero]

I set the v/div to 1v and the square wave on pin 9 and 10 on the ic seems perfect and after driver transistor "to gate of the fet" the signal is the same

An externally hosted image should be here but it was not working when we last tested it.

 

[Ground Zero]

If this is ok could you tell me the next step please ?

 

[Perry Babin]

If 9 and 10 look like that, check the signal on the gate pads for the power supply FETs. Check all pads. The gate pad signals should look very much like this.

 

[Ground Zero]

for the moment on the pad of each gate i have the same signal .

I haven't put mos-fet, the transformer, and diode rectifier.