Pre-made power supply for Quickie

[boulos]

Hi,

Would this AC/DC converter be suitable for the quickie, assuming I still want to run the filaments on batteries (these last a long time):
http://www.us.tdk-lambda.com/ftp/Specs/zms100.pdf

There are 36V and 48VDC output versions.

Thanks
Boulos

 

[Paul Birkeland]

These are basically the guts that you might find inside your average laptop power brick.  They prioritize high power and high efficiency (to keep the heat down).  On the negative side, these little switching supplies are super noisy, and may not have such great regulation at low currents (though this datasheet says otherwise). 

You could give it a try, but the batteries will almost certainly sound remarkably better.

 

[boulos]

I see.  They tout it as this super awesome supply.  Maybe it is, but I guess not for our purposes.  Thanks for looking at it.

 

[Paul Birkeland]

Yeah, for the type of power supply that it is, it is super awesome!  It's reasonably low ripple, and regulation is much better than what you normally get, but it's still a switching supply.

-PB

 

[Grainger49]

Batteries are very low noise, good ones are very, very low noise.  Is there a reason you need an AC sourced power supply or are you just wanting build one for fun?

 

[boulos]

The main reason is that the 9V batteries I have run out very quickly, discharging even when the Quickie is off.  I've only used Duracell and I'm quite disappointed with them (though the D-cells are great).  I should just try other brands before judging.  Any recommendations?

 

[Grainger49]

I remember your thread now.  It seems that there would have been a problem found. 

I know of a DIY power supply but it only goes to 30V.  Two could be adjusted for 36V.  Maybe with different regulator chips one would go to 36V. 

Are you interested?

 

[boulos]

I had stopped using the Quickie, so shelved this issue. Now I want to use it again, and I'm running into the same problem.  I can either try the rechargeables recommended to me earlier, or try a different brand of Alkaline batteries.  Still, I would greatly appreciate a pointer to the DIY power supply.

Thanks!

 

[Paul Joppa]

Boulos, you should not be seeing that behavior - something is wrong. It might be the build, or an unexpected problem in the design. Is this the 1.1 version or the original?

 

[boulos]

Hi Paul,  this is the Quickie 1.1 with PJCCS, all stock except for the output caps. 

I can check voltages again and post the results and pictures of the build later tonight when I'm back from the office.

Thanks!

 

[mcandmar]

It may just be bad battery's.  I've had a bad batch of Duracell 9v's that all discharged and blew their end caps out in a very short time.  Replaced them with cheap rechargeables from eBay that would discharge in three days sitting on a shelf.  But they aren't all like that, i have a set of energizer's that have lasted forever.

If you really want to go AC powered check out my Project Babybottle thread in the gallery section.

 

[boulos]

Apologies I couldn't get this done last night as promised. 

All the resistance and voltage checks measured OK except for two possibly peculiar measurements:
Resistance (no batteries): Terminals 1,4 on the rotary switch measured 100kOhm (not "infinity")
Voltage: Terminals A6 and B6 measured 26.88 and 24.72 (not between 19 and 21 as the PJCCS manual specifies).

Also, when the batteries are installed, but the Quickie is off, I noticed that terminals 4 and 9 measure 0.26V (similarly for Kreg and -reg).

Attached are a couple of pictures of the build.

Thanks for all the help!

 

[Paul Joppa]

Well, you have found the problem - the T4/T9 measurement indicates current being drawn. It's very late here so I have not yet tried to figure out why, but PB will probably nail it in the morning.

 

[Paul Birkeland]

How're your battery voltages?

 

[boulos]

How're your battery voltages?

They seem to be OK:

9V: 9.3, 9.3, 9.3, 7.6 (didn't have a 4th new battery)
D: 1.57, 1.57

Boulos

 

[boulos]

There's definitely a leak somewhere. The batteries are already 9.27V (they were 9.31 earlier and the instrument I'm using is a BK 2709B).  Here's a picture of the bottom of the PJCCS board if that helps.

 

[Paul Birkeland]

Is that connection at bA loose?

 

[boulos]

It appears so in the picture, but it's actually good.  I also just verified continuity from two other terminals connected to it.

 

[Paul Birkeland]

Pull the tubes and recheck your "off" voltages.

-PB

 

[boulos]

T4, T9 and -reg are still 0.26V without the tubes.  Kreg went to 0V.