BOSOZ Psu

[Ilianh]

I found some IRF610 in my stuff and I'm about to start a BOSOZ project.

The only thing bugging me off is, how "special" does the power supply have to be?
looking at this...

http://web.vip.hr/pcb-design.vip/bls-pwr.html

...

cant i just give it +/- 60v dc and be happy


the problem is the IRF9610 in that psu, I cant find it localy and I dont want to order it via internet for this project, the closest I can get is the IRF9630, any good?

[Mad_K]

irf9630 will do just nicely

[moe29]

i did a stupid thing today. i powered up my BOSOZ power supply
without loading the V+ with 15 Kohms ¼ watt to ground and the
V- with 15 Kohms... i blew all the zeners and the mosfets.

just when you think you're learning something...

POOF, you let the magic smoke out...

well, i guess i at least learned not to do that.

could someone explain to me why it does this without a load?


thanks

m.

[Ilianh]

oh..

well.. I'll try not to do that

BTW, could I use this bosoz as a head phone amp?

[PassFan]

Originally posted by moe29
i did a stupid thing today. i powered up my BOSOZ power supply
without loading the V+ with 15 Kohms ¼ watt to ground and the
V- with 15 Kohms... i blew all the zeners and the mosfets.

just when you think you're learning something...

POOF, you let the magic smoke out...

well, i guess i at least learned not to do that.

could someone explain to me why it does this without a load?


thanks

m.

It's been so long since I built mine I can't remember that happening to me. I couldn't tell you why. Where in Florida are you located? I am in Lakeland close to Orlando.

[moe29]

i'm in Clearwater

i just de-sodered all the zeners (all toast) and the MOSFETS.

i guess the caps are still good, not sure about the diode bridges.
my RS voltmeter has a diode setting. when i check the bridges,
it gives me a reading, but it's not stable... the V just keeps
increasing...

i did double check all the parts values, cap polarity, zener polarity,
etc. I mean it's not that difficult to stuff a board with the correct
parts... i suppose the parts blew because i didn't add the resistor
loads before turning on the power supply...


m.

[grataku]

Originally posted by moe29
i did a stupid thing today. i powered up my BOSOZ power supply
without loading the V+ with 15 Kohms ¼ watt to ground and the
V- with 15 Kohms... i blew all the zeners and the mosfets.

just when you think you're learning something...

POOF, you let the magic smoke out...

well, i guess i at least learned not to do that.

could someone explain to me why it does this without a load?

I never heard of that. I do believe I checked the PS of my BLS with no load and nothing really happen. Sounds to me like you got bigger problems than the lack of a 15 kohms load.

[PassFan]

I can't remember if I had mine hooked up to the circuit or not when I powered it up. I don't think the absence of a load would cause all that damage. Things to consider would be did it occur on both the + and - side. Without the mosfet or zeners installed power up and make sure you have + volts on the + side making sure that your bridges are in right and not backwards. I think if you hit those zeners backwards they will blow and I'm thinking of any way the voltage could wind up wrong. Everyone who has ever made a mistake with this stuff has looked right at it 20 times wondering why before it hit them. Be persistant, it will work. Sometimes I walk away and come back later. Good Luck

[moe29]

i just double checked the point to point wiring for the
transformers and all is well there, i'm getting 38 volts AC
on the secondaries. The transformers are Avel Lindberg
Y236107's rated at 2x115v - 30v secondaries. Am i
getting 38V becasue of the 115v trans?

i just checked the bridges and the polarity is correct.

it may have been that the zeners were no installed
correctly... i allready de-soldered them! and i didn't
take a picture to document.

i agree absence of a load shouldn't have caused that...

when i get new zeners i'll triple check for correct polarity.

thanks for the replys, i'll get back to you when i try again!

this always happens when i try to build things from scratch!
i've built lots of kits with no problems....
---------------------------------------------------------
I did as PassFan suggested and took some readings
without the zeners or MOSFETs installed. Reading
across the caps right after the bridges i was getting
+103.5 VDC and -104.4 VDC. i notice these readings
are a lot higher than the 80VDC reccomended from
the article... could this be because of no load?




m.

[Ilianh]

You guys think this could be used as a headphone amp?

What headphones impedance would be safe?