PSU repair

[maldihtah13]

Natapos ko na rin pc power supply to bench power supply ko

[Woots29]

bos nomad13, pwede bang maging adjustable ung supply ng pc pow supply u?

[maldihtah13]

bos nomad13, pwede bang maging adjustable ung supply ng pc pow supply u?

Actually may ginagawa me ngaun digital power supply with adjustable output and current limiter. Target ko eh 0-30V 0-3amps. Pero bka 25V lang ang mangyari dahil sa kawalan ng available transformer.

[Woots29]

bos bka pwedeng pahingi ng diagram nung variable curent. kc puro voltage lang ang alam ko

[akosiikem]

Actually may ginagawa me ngaun digital power supply with adjustable output and current limiter. Target ko eh 0-30V 0-3amps. Pero bka 25V lang ang mangyari dahil sa kawalan ng available transformer.

Bro meron sa raon, sa eleshop toroidal x'former 40v ang secondary and 6A ata aroung 700php yun

[maldihtah13]

bos bka pwedeng pahingi ng diagram nung variable curent. kc puro voltage lang ang alam ko

actually ung voltage ang pinababa nya para maging constant yung current. Tapusin ko muna pra nman cgurado na working ito. Based sya sa digital power supply ng alexan pero PIC ang gagamitin ko controller.

Bro meron sa raon, sa eleshop toroidal x'former 40v ang secondary and 6A ata aroung 700php yun

Gud news cge magpapabili na ako dun.

[akosiikem]

Pa OT ha

nomad yung project mo ba yung may constant current mode and constant voltage? Yun kasi balak ko gawin
at yung dual tracking na PS for opamps testing.

 

[maldihtah13]

Pa OT ha

nomad yung project mo ba yung may constant current mode and constant voltage? Yun kasi balak ko gawin
at yung dual tracking na PS for opamps testing.

 

yes sir, nakita ko plan sa electronic enthusiast kya lang motorola ang controller. Papalitan ko ng DAC ska ng MCU.

[pampubliko]

@akosiikem

Thanks ^_^

[pampubliko]

 Thanks sa link dude ^_^

[ferdie444]

@pampubliko,pls check the foil side of your pcb @ baka merong carbon formation(psu)otherwise,pls check the output of your x/tor w/ and w/out load @ baka me tama na cya.ung transformer mo,paki check din kung walang vibration or humming sound kapag mainit na ung psu unit mo?and finally,how about the fan?nsaubukan mo na bang idisconnect un pag may load?baka un ang nag-iinit @ nangangamoy?thanks and more power....

[ydlazatp]

anong posibleng sira pag mataas ang 3.3v,5v and 12v,iyong 12vdc kasi umabot ng 14vdc at ung 5vdc ay umabot ng 6.5vdc.

[glutnix_neo]

anong posibleng sira pag mataas ang 3.3v,5v and 12v,iyong 12vdc kasi umabot ng 14vdc at ung 5vdc ay umabot ng 6.5vdc.

check nyo output rating ng power supply nyo. Kung alin dun ang may pinakamalaking output power(Vout * Iout), malamang 3.3V, Chances are dun xa nagreregulate(feedback to PWM are coming from this output),

check nyo ngayon kung tama output nung may pinakamalaking output power. Kung tama naman, I think its natural for other outputs na tumaas kasi hindi sila loaded.

[ydlazatp]

sir anong possibleng sira pag may whining sound ang psu?thanks :

[Shey]

sir anong possibleng sira pag may whining sound ang psu?thanks :

suspect diyan ang capacitor or yung transformer mismo..

[macky]

ano naman ang sira pag yung green wire(PWRON) connected to COMMON(black wire) ay parang pipitik lang ang output, hindi tumutuloy ang oscillation.

[Shey]

ano naman ang sira pag yung green wire(PWRON) connected to COMMON(black wire) ay parang pipitik lang ang output, hindi tumutuloy ang oscillation.

maraming causes yan..

1. faulty PWM chip (TL494)
2. faulty comparator chip (LM339 or LM393)
3. shorted components
4. faulty optocoupler

[macky]

^thanks sir electron, will try to check those probable causes.

[ydlazatp]

maraming causes yan..

1. faulty PWM chip (TL494)
2. faulty comparator chip (LM339 or LM393)
3. shorted components
4. faulty optocoupler


sa no.3 sir saang side ang sira,primary or secondary?

[glutnix_neo]

maraming causes yan..

1. faulty PWM chip (TL494)
2. faulty comparator chip (LM339 or LM393)
3. shorted components
4. faulty optocoupler

in short, nagopen loop ang feedback path at possible na nahihit ang protection (overvoltage protection)