VOTE: Logisys 480W vs. L&C 450W

[Newbie2]

I have made a vote thread to see if people prefer Logisys or L&C. The power supplies shown here are etnietering's Logisys 480W power supply, and my L&C 450W power supply. Both have been modified for improved performance.

Newbie2's L&C 450W PSU


etnietering's Logisys 480W PSU


Guys, what power supply do you like more?

[ratdude747]

Re: VOTE: Logisys 480W vs. L&C 450W

if i could, then i would vote "kill both units, buy delta, etc."

both are unsafe in my opinion.

[etnietering]

Re: VOTE: Logisys 480W vs. L&C 450W

Well mine definitely wins. Want to know why? I put LEDs in it hehehe

[KeriJane]

Re: VOTE: Logisys 480W vs. L&C 450W

Hello

I'd vote for them both if I could.

But what about the stunningly re-engineered Bestecs of everel?

All of you guys going out and making a silk purse out of a sow's ear just amaze me. In a GOOD way that is.

It's like ummm...
Building your own PSU?
Making a tercel car win the Indy 500 race or something?
Maybe breaking the sound barrier in a hang glider?

Have Fun,
Keri
PS.....Send one out to JonnyGuru for a bargain basement PSU review as a joke.

[370forlife]

Re: VOTE: Logisys 480W vs. L&C 450W

Both are a lot nicer than they were before, but I'd have to say the logisys because it has a little more output filtering, that extra X cap on the receptacle, and the main transformer looks just a bit more beefy.

[lucky13]

Re: VOTE: Logisys 480W vs. L&C 450W

Well mine definitely wins. Want to know why? I put LEDs in it hehehe

I did not see any picture showing the LEDs working....so... can't let you win on that note. Are you gonna to post a picture showing the LEDs working? That might swing my vote....

I do like those beefier aluminium heat sink already on yours.

[ratdude747]

Re: VOTE: Logisys 480W vs. L&C 450W

i still think they are ticking time bombs. heatsinks too wimpy.

[linuxguru]

Re: VOTE: Logisys 480W vs. L&C 450W

Both seem about equal - I'll probably go with the Logisys for its extruded heat-sink, and commodity ICs (LM339 and TL494).

[momaka]

Re: VOTE: Logisys 480W vs. L&C 450W

Kind of hard to decide actually.
Pros (Newbie2's PSU):
-better coil for the input filtering
-slightly better heatsinks (even though they are stamped, they're slightly thicker)
-200v 20A schottky rectifier for the 12v
-new Sunon fan
-excellent voltage regulation and stability when tested (and still powering) with a P4 2.2 GHz Celeron

Cons (Newbie2's PSU):
-Single PWM IC labeled "2003" with unknown capabilities (probably lacks protections)
-1kv ceramic caps rather than Y caps on primary

Pros (etnietering's PSU):
-Better 3.3v rail caps
-bigger primary caps (820uF)
-2x PWM ICs (means there could be better protection)
-5vsb coil and new caps
-120mm fan

Cons (etnietering's PSU):
-input PI coils rather than a big choke/coil
-top half of the heatsinks has good fins but the core is tiny

Both of you put a lot of time and hard work in those, so I really think they are more or less equal. The real way to find out is to load test them with a 200 watt load and check for ripple and noise with an oscilloscope.

[ratdude747]

Re: VOTE: Logisys 480W vs. L&C 450W

i vote for this one

[Newbie2]

Re: VOTE: Logisys 480W vs. L&C 450W

i vote for this one

It looks like a Deer power supply judging from the fan grill.

[everell]

Re: VOTE: Logisys 480W vs. L&C 450W

I think there are two important safety considerations in choosing between the two power supplies. First, if you put a short across the output voltages (one at a time), the 12 volt rail, the 5 volt rail, and the 3.3 volt rail ................. what will the power supply do? Is it a fire hazzard? Will it protect itself or will this test damage the power supply? A good power supply should be able to handle this situation.

Secondly - design of the 5vsb circuit. Most of the circuits I have seen have an electrolytic capacitor used as a filter on the feedback winding. When this capacitor ages and esr starts going up ....... what will the power supply do about it. The Bestec ATX-250 12E goes boom - or at least lets the 5vsb voltage go high enough to kill a mother board. I have tested the L&C with the two transistor design, and it will allow the 5vsb to go high. Modify this 5vsb circuit and you won't have to buy as much fire insurance. I'm not sure what the Logisys has as a 5vsb circuit.

Remember - if the 5vsb is dead, the power supply won't start up. If it goes overvoltage other big problems follow. You cannot afford to ignore the 5vsb circuit.

My vote - I am glad to see more of us improving these inferior power supplies. But I don't think we are finished. Both of these two are about neck and neck for what has been accomplished. Great job guys.

[Newbie2]

Re: VOTE: Logisys 480W vs. L&C 450W

I did place a brand new Panasonic FC series 47uf 50V capacitor at C8 (the spot for the +5VSB capacitor according to everell) when I did my work on it, I hope that should last for the length of time I will use my Celeron 2.2GHz computer.

[everell]

Re: VOTE: Logisys 480W vs. L&C 450W

Well ........ if I'm going to tinker with my L&C, I might as well see what kind of safety features it has. So here we go................

I placed a short across each output rail (one at a time) to see what the result would be. In each of the three cases, the power supply crowbarred (shut down and latched). The 5vsb was still on and active, but all three of the output voltage rails stopped. I had to turn the PS-On switch to off. Then turn it on and the power supply resumed normal operation. No damage to the power supply. Looks like the pwm and its supervisory functions (all in one chip) are working quite well. Better than I expected. So my next step will be to experiment with the 5vsb.

As for changing the critical 5vsb capacitor, a good idea, but under what conditions does a capacitor fail? Age is not the only reason. It is still bad design ..... or should I say - not the best design for a safe power supply. I am debating whether to try the TOP222 or the DM311 circuit.

[Newbie2]

Re: VOTE: Logisys 480W vs. L&C 450W

Well a capacitor can also fail under high heat, but the Celeron 2.2GHz computer I put it in doesn't run hot (since it isn't a power-hungry computer and plus it is not overclocked) and the STTH2002CT 200V 20A power rectifier should produce less heat than the two 3A 100V FR302 diodes it had earlier for the +12V rail.

An electrolytic capacitor can also fail quickly if the polarity isn't correct, but I do check the polarity of every cap I install and make sure it is right. If it wasn't right then in my case the cap I put in would probably fail soon after I powered up the power supply.

Even though it isn't the best design, under the conditions I have for my L&C power supply the capacitor I installed should last for a while.

[Gianni]

Re: VOTE: Logisys 480W vs. L&C 450W

Most of the circuits I have seen have an electrolytic capacitor used as a filter on the feedback winding. When this capacitor ages and esr starts going up

As for changing the critical 5vsb capacitor, a good idea, but under what conditions does a capacitor fail?

I think a good cap should not fail there, there is not high current on feedback winding, probably most fails because are not the right type (105ºC/LOW ESR).
If you don't want a lytic there you can use a MLCC.

For the vote: you guys have done a lot of work but I think some modification that impact on EMI and safety aspect are too much out of my idea of FIY, for this reason I would give 0.5 both... if it were possible.

Ciao
Gianni

[etnietering]

Re: VOTE: Logisys 480W vs. L&C 450W

by request of Lucky13, I took a (bad) picture of it running with the LEDs on. Sorry it's so lame....but my camera needs like 1 second exposure time and I don't have a tripod, and I can't really use the flash....

[Newbie2]

Re: VOTE: Logisys 480W vs. L&C 450W

by request of Lucky13, I took a (bad) picture of it running with the LEDs on. Sorry it's so lame....but my camera needs like 1 second exposure time and I don't have a tripod, and I can't really use the flash....

If green LED lights are what you like then putting one of these 120mm fans in your power supply will definitely make it light up!

http://www.newegg.com/Product/Produc...82E16811998122

[ratdude747]

Re: VOTE: Logisys 480W vs. L&C 450W

looks awesome. very nice.

[etnietering]

Re: VOTE: Logisys 480W vs. L&C 450W

well they were just something I found in my basement when I was working on it, and decided to put them in. Also, I forgot to mention, I replaced the crappy logisys fan in it this past spring and put in a nice silverstone fan from my case. I was surprised that the fan it came with wasn't soldered directly to the board, but it had a connector. However, in the process of trying to unconnect it, it ripped it off the pcb...that was the first thing that told me what a high quality product I had purchased....so now the silverstone fan has it's 3 wire connector coming out with the rest of the wires. Right now I have it plugged in to a molex adapter, but should I ever use it in a computer I could plug it into the mobo and have it be thermally controlled.