[Garbz]

now that would even keep my main amp going!

 

[Garbz]

Ok here's the latest. The powersupply pre regulator sits at 25.8v. At power-off it takes almost a full second to drop below 4v (i'm running a 12v time delayed relay circuit through a resistor divider so 4v becomes the new critical switchoff votlage).
However post regulator where my newly installed 2200uf cap is still drops too quickly and when i turn off I still get a massive power spike. I can only conclude that 2200uf is not enough to keep this running long enough.

Is there anyway to cause the voltage pre-regulator to drop more quickly so the relay gets triggered earlier? If no i'll have to start whipping up a simple logic board to controll the power-on/off.

 

[rickcr42]

take the relay voltage right after the rectifiers and before any filter caps

 

[Garbz]

firstly i don't think that's possible since the capacitor, bridge, and input of voltage regulator would elecrically all be the same point.

To make matters worse i'm using a 24v wallwart, and I am taking the juice direclty from the switch.

 

[rickcr42]

Quote:

To make matters worse i'm using a 24v wallwart, and I am taking the juice direclty from the switch.

I had meant to say before the rectifier and just add a single IN4001 from the transformer but the all in one wallwart kinda kills that idea.looks like you are screwed but

What is the deal with your AC going "brown out" on you all the time ?

grid related ? House ? Apartment building with too low a service ?

Maybe instead of a bandaid you need a cure dude

 

[rickcr42]

BTW-I think a rechargable Lead Acid Battery supply is your only true fix here.The only time AC is connected is during the charge stage when you are not listening and if designed correctly could give you ten hours or more of continous listening without any shut downs or glitches

 

[Garbz]

yeah lead acid batteries are heavy, but it does sound like the way to go.

No idea why our AC browns out all the time, but it's most probably grid related. It's rare that I take my 10min walk to the train without seeing some Energex guys clinging to a pole messing with some wires.

But the point of this problem here is when my computer will get taken to LAN parties. As soon as some ******** brings in his custom water cooling unit all so he could get a few more Hz from the chared remains of an over overclocked ****box, the power goes out! It happens about 6 times during the day at these events.

We actually activily banned one person's rig who had such troubles after he killed the power during a competition, and told him he'll only be allowed in next time AFTER his computer has had a complete inspection

 

[Garbz]

actually i'm not quite prepared to throw in the towel yet.

http://www.garbz.com/amp/prot-circuit.pdf

This is something I just whipped up which may help. It's very similar to the last circuit I used with a few key differences.

A zener diode will in theory increase raise the turn-on voltage for the darlington pair, correct? I don't mess with them much so it wouldn't surprise me if that is wrong.

Secondly, rather then letting the cap discharge through the 47-300k that charged it up, a diode and 10r resistor is inplace which will kill the cap instantly.

I figured if this still doesn't cut it i'll raise the cap value, after that it's to that lead acid batter

What you'r opinion on it rick?

 

[amb]

Quote:

Originally Posted by Garbz A zener diode will in theory increase raise the turn-on voltage for the darlington pair, correct? I don't mess with them much so it wouldn't surprise me if that is wrong.

Yes it would.

Quote:

Secondly, rather then letting the cap discharge through the 47-300k that charged it up, a diode and 10r resistor is inplace which will kill the cap instantly.

I don't think that diode and resistor would actually help much. If the +12V supply actually falls fast enough to make that work, then it should have dropped below the disengagement threshold of the relay even without discharging the cap.

 

[Garbz]

Ok guys fixed

I put a diode in series with the powersupply before the regulator. That when when i flick the power off that pre-diode section looses power instantly. No more juice bleeding out of the regulator.

Flick the switch and the relay click off instantly, no more problems! I get a thump of about 2mV

Time for dinner then i need to neaten this mess :S Thanks for everyones help. Especially rick. I still love your capacitor el grande idea

 

[Garbz]

Heres a wiring job to scare off rick

 

[rickcr42]

love the top plate layout man,very unique thus cool

the bottom part....um....errr......what was the question ?

oh yeah...............


[size=large]buy some terminal strips dammit !!!!!!!!! [/size]

 

[Garbz]

Then i'll have them floating around, because i don't have any glue

Anyway it works and is all good. I'll post the final one next week when it's assembled in my computer.

 

[rickcr42]

Quote:

Then i'll have them floating around, because i don't have any glue

they don't sell mounting hardware down under wise guy ?

i see two unsuded holes in the top plate that look like ideal for terminal strip tie downs.

BTW- i do hope you plan to cover those exposed mosfet leads,just looking for a short if you accidently drop a pen or something on them

PFFFFFFT ! Release the magic blue smoke from the box !

 

[Garbz]

Yeah i will. I'm waiting on a trip to jaycar where i'll buy some liquidised electrical tape which i'll smear on. Also around the insides of thoes slits i've cut incase a pin gets bent.

The 2 holes were for doing something creative, i'm not sure what yet but I think i'll mount a disc halfway up the tube just for visual effect which will be bolted into thoes holes.

Either way considering the ammount of movement this thing will get I'm going to stop just short of dunking the entire thing in silicon