# Pyramid Power Supply Overload



## Scafremon (Dec 11, 2006)

I just plugged in my new PS30LAB power supply, and the overload light is flashing and unit beeping. I have no load connected to it. 

I'd like to hear from other members that have Pyramid power supplies, even other models, if you have encountered this, and also, some details on the units you have.

I ordered the PS32LAB, but received the PS30LAB. Only difference appeared to be I received LCD meters instead of analog meters. Now I am looking at it more closely, and noticed a couple things that may or may not be a factor.

First, the PS32LAB was advertised in the bid as "Input: 110/120VAC 60HZ".

The box for the PS30LAB I received says same thing, but includes a "220/230V 50HZ" rating.

The brief instruction book (read: page) I received with the unit says "Input: 220VAC 50HZ, 110VAC 60HZ, Switch setting".

The switch on the back of the unit has 2 values printed on it: 115 and 230.

I tested the voltage at my outlets and they are 117V (which sounds appropriate for a 120V service), and being in US, it should be 60HZ.

In summary, I believe the unit I received is not suitable for the 117V 60HZ I have available. It's also strange that if I google PS32LAB - tons if hits. PS30LAB - just one website (which if you go to, has pop-ups).

Marty/TGTycopro: What does the switch on the back of your units say, and did you get any better literature with your model of Pyramid PS's?

Thanks guys.

Jeff


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## aelancaster (Apr 8, 2006)

Try setting the switch on the back to the 110V setting.
Andy


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## Scafremon (Dec 11, 2006)

I tried both settings Andy.

If any of you have a Pyramid Power Supply of any model (or possibly even another power supply) do you get an overload if you turn the amps dial down to near lowest setting?


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## Scafremon (Dec 11, 2006)

I got the power supply to work for the most part. As long as I don't turn the amp setting dial down to almost off, I don't get the overload warning.

Now the problem is the voltmeter isn't reading voltage. It just shows a "-1".

When I hook up a test meter to the track, and squeeze a controller, the test meter registers the volts, but the unit display doesn't change.


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## BRS Hobbies (Feb 16, 2006)

It sounds like you might have received a power supply for the European market as they use 220 volts. If you ordered a PS-32 lab and got a PS-30 lab, then I would try contacting the retailer about an exchange.

Best regards,
Brian


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## donster (Dec 13, 2005)

Except for the voltage meter always reading “-1” it sounds like your power supply is working normally.

Most modern electronic equipment these days is designed for the world market and that’s why it has both “110/120V 60Hz.” and “220/240V 50Hz.” specifications. Set the switch to “115” if you’re in the U.S.A. and you’ll be fine. Your supply will operate normally on the 117V that you measured at your outlets. Actually, it should work fine anywhere from about 90V to 130V input without any trouble.

The overload condition that you saw when you turned the amps control all the way down is normal. The overload light will come on when the control is set all the way down because the comparator circuit is comparing the actual current, zero amps, to its reference, which is also zero since the control is all the way down. The light indicates that the current draw has equaled or exceeded the current setting and the electronics has limited the output current to this setting. Depending on how the current limiting circuitry is designed and the speed at which it reacts to increasing loads, you may see this light flicker on when you have a sudden increase in current draw such as when you squeeze your controller from “full off” to “full throttle”. All that light indicates is that the circuitry has clamped the current output to whatever amps setting you have dialed in on the control.

While I definitely wouldn’t consider this unit a “laboratory” grade power supply, it’s certainly fine for slot car use. I downloaded a copy of the manual for the PS32LAB model to have a look at it and, I must say, it wasn’t much of a manual. It didn’t give any technical information and was basically useless. I wasn’t able to find a schematic or any technical information for either the PS32LAB or the PS30LAB models but I would suspect that they are both identical except for the meters.

With respect to the malfunctioning voltage meter, try unplugging the unit, disconnect the output leads, and let it sit for a while. It might not help but, who knows, it just might. Without a schematic of the unit I couldn’t even begin to suggest anything to look for. If you are brave enough to open the unit and look inside (Safety First - make sure you unplug it), look for any loose connections, broken or disconnected wires, burnt components, bad solder joints, etc. It might be something simple. If not, hopefully the establishment where you purchased it has a decent return/warranty policy if you decide to go that route.

Regards,
Don


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## Scafremon (Dec 11, 2006)

I took your suggestion Don and opened up the unit.



I didn't see any loose wires or bad connections.

I concentrated at the rear of the LCD units. The LCD's are basically the same for current and volts - they just have a few differences between them.



They each have a 9v power input, and the voltmeter has 2 wires that run to the output posts. The solder connections at both ends of these wires appear ok.

One difference between the 2 displays is in the upper right of each. The voltmeter has a connection at P3, while the ammeter has a connection at P2.





It looks like both of these may of previously had connections on both locations. Maybe they are mass produced that way, and the OEM removes the one he doesn't need based on the meter's purpose? It's hard for me to tell if on the voltmeter there may still be some solder connecting P2.

Of course, I could just be seeing things as I look for a problem.

I exchanged emails with the seller a couple days ago, and hope to have a conversation with them soon. 

Thanks for your input on the problem! 

Jeff


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## donster (Dec 13, 2005)

Looking at the pictures, my guess would be that the P1, P2, and P3 connections are used to set the meter to a specific range for the display. That is to say that it probably sets the decimal point position or number of digits displayed.

It looks like there's a loop of wire from Vin to GD on the right-hand meter. I would guess that it is a piece of resistor wire cut to a specific length that they are using for a shunt. The circuitry uses the voltage drop across that piece of wire to derive the current reading. 

There doesn't appear to be any damaged components on the circuit board from what I can see in the photos so if the meter still won't work after you put everything back together and you are able to measure voltage output then that meter is probably toast.

Hope you can resolve things with the seller.

Don


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## Scafremon (Dec 11, 2006)

Well, I put everything back together, and now the meter works. Maybe a tin whisker was causing the problem, and dis-assembly resolved it.

I probably wouldn't have done all that if you hadn't prompted me Don, so thanks again.

Jeff

PS: In a related story, I have posted a PS30LAB for sale on Ebay. Brand New - Works Flawlessly!  (j/k)


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## Scafremon (Dec 11, 2006)

Now that the meter works, I have a new problem.

No matter where I set the voltage dial, the meter voltage creeps up or down until it rests at 22VDC.


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## Ragnar (Aug 22, 2006)

Scafremon said:


> I tried both settings Andy.
> 
> If any of you have a Pyramid Power Supply of any model (or possibly even another power supply) do you get an overload if you turn the amps dial down to near lowest setting?


Only if I have a motor, or a tyre truer hooked up to it. I only use my PS 32 LAB at the work bench, it's great for breaking in motors and running D.C. equipment such as tyre truers, andd com lathes. :thumbsup:


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## Scafremon (Dec 11, 2006)

I played around with my power supply some more.

When I took the 3-sided cover off of the unit, the voltage would hold a constant value. Back on and screwed down, voltage fluctuates.

If I just set the cover on, the voltage stays constant. Got to be the screws then, but I checked each screw, and none are getting anywhere close to an electrical contact point.

After much trial and error, I was able to determine that when I attach the cover AND put in the screws, the base of the power supply twists ever so slightly to line up with screw holes in the cover.I could then replicate the voltage creep with the cover off, and just slightly (like .25") lifting the front/right corner of the unit. 

Even with this slight movement, nothing insire is really moving all that much, but it is causing some type of problem.

I'm hoping that I can fix the unit, so as not to hassle with returning it and such, but at same time, I just sent an email to the supplier asking for a replacement.


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## donster (Dec 13, 2005)

First thing I would do is verify, with a separate meter, that the output at the terminals is actually going to 22 volts and that it’s not just the meter on the front giving a false indication. If the actual output is wrong then it sounds like you've got a cracked solder joint somewhere on your circuit board. It wouldn't take much flexing to cause the problem you describe. The amount of circuit board flex might be unperceivable to the naked eye.

I would concentrate on the main/large circuit board on the bottom of the unit first. You’ll have to remove it from its mounts to examine the bottom. Use a magnifying glass or jewelers loop and see if there are any joints that look dull, pitted, or grainy (cold solder joint) or any that seem to have a ring all the way around between the outer edge of the solder and the component lead in the middle (cracked joint). Solder joints should be reasonably shiny, smooth, and even all the way around the lead of the component sticking through the hole.

Also, check the wires going from the main/large board to the small board mounted on the heat sink. That may be the regulator board and a loose connection or bad solder joint there would also cause similar symptoms to what you described. I can’t tell from the pictures whether there’s a plug-in connector or some other kind of connector there but that might be something to look at.

One other thing, and I can’t tell from the pictures, but if those IC’s are mounted on sockets, you might try pulling them out and re-seating them. Dirty or corroded contacts on IC sockets can cause you grief too. Spraying them with a little contact cleaner, if you have any, before putting them back in would be a good idea.

It’s hard to tell how much shock the unit received during shipping. Even if it was packaged fairly well, a good jolt could have caused something to flex enough to crack a solder joint. I can’t tell from the pictures but that large filter cap in the center of the board doesn’t appear to have any RTV (silicone) or hot melt glue securing it. I’d look at that area closely. A good jolt would probably cause that thing to flex due to its high center of gravity.

If you can’t find anything blatantly obvious, you could just go around and re-touch all the solder joints on the board. Just watch the amount of heat you apply to the IC legs if they’re not on sockets. If they are in sockets, remove them before re-soldering the socket leads and make sure to put them back in the same way they came out.

Good luck.


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## RiderZ (Feb 19, 2007)

I pm'ed the guy on ebay who you bought your PS from asking if the one pictured in the auction is the one you will recieve.He replied back saying it is the one you will recieve.The one i'm looking at is the ps32lab-i'm thinking of purchasing it for $69 but im a little nervous about it after reading your post!!!


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## Scafremon (Dec 11, 2006)

donster said:


> First thing I would do is verify, with a separate meter, that the output at the terminals is actually going to 22 volts and that it’s not just the meter on the front giving a false indication. If the actual output is wrong then it sounds like you've got a cracked solder joint somewhere on your circuit board.


I thought I had done that test, but after more thought, I remembered I had not. What I did instead was set the power supply at 10volts, and then started running a car on wide open throttle. I got about 5 laps in while the power supply creeped up to about 12 volts and then the car deslotted. I felt the car was increasing in speed while the voltage climbed, but maybe the car and the track were just warming up.

I did get a call from Pyramid this morning, and he asked me to do the exact same thing you have reccomended. I will try that tonight and call him back tomorrow. If the output voltage is constant, Pyramid says they will send me out a new LCD, and I’m pretty sure I can get that installed myself.



RiderZ said:


> I pm'ed the guy on ebay who you bought your PS from asking if the one pictured in the auction is the one you will recieve.He replied back saying it is the one you will recieve.The one i'm looking at is the ps32lab-i'm thinking of purchasing it for $69 but im a little nervous about it after reading your post!!!


I’m not sure if the seller I bought from (Electronic Liquidator) currently has any PS32LAB’s on ebay. I do see a Electronic Giant selling them, who is in New York just like Electronic Liquidator (same seller?).

I hope to advise soon that this issue has been resolved to my satisfaction. It was a positive step to have someone call me from Pyramid (claiming to be in any case, but he was knowledgeable about the product).


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## donster (Dec 13, 2005)

I know that power supplies have been a hotly debated topic on other threads on this site and I really don’t want to re-open a can of worms, (uh-oh, here it comes) but, there was a lot truth in what was said about cheaply built products from overseas.  The old adage; “You get what you pay for.” certainly applies with these products. That’s not to say that if you get one that works fine and does the job that you still got ripped off. On the contrary, if you’re satisfied with it then that’s great.

However, as we’ve seen happen in this thread, lots of little irritating problems can frustrate the hell out of you. You’ve paid good money for a product and it’s not performing properly. And it’s especially frustrating on a product that’s brand new. Hopefully the seller or the manufacturer of this product will make things right. Unfortunately, you’ll always have that thought in the back of your mind that makes you wonder how long it will be before something else goes haywire.

Even the most expensive and highest quality electronics will eventually fail. It’s inevitable. Age catches up to everything; mechanical, electrical, and biological (as we all know too well). However, it takes a little longer with things that are built to a higher standard.

If I was going to purchase a power supply I would look at some of the true “laboratory grade” units available. Just a quick look on “the bay” turned up a nice Hewlett-Packard 0-20V / 0-10A supply that would be perfect for a slot car track. Item number is 270163213142 if you’d like to have a look. (I have no association with the seller of this item whatsoever and I’m only using this as an example.) Current bid is about $20.00. I’m sure these units probably were well over $500.00 when new.

Now, I realize that most guys on this board aren’t electrical engineers and might be reluctant to buy a piece of used gear being sold “as-is”, but these units are nearly indestructible. If it powers up it’s probably fine. Constant current, constant voltage, overload protection, an overall beautiful piece of equipment. And built to a quality standard far above that of a Pyramid supply. Hell, the transformer alone in the HP probably weighs more than the entire Pyramid supply.

So, there are some very high quality, low cost, power supplies out there if you know what to look for. And if you’re not afraid to buy a used piece of gear you can really get some top-notch stuff that will give you years of reliable service.


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## RiderZ (Feb 19, 2007)

I just purchased the ps32lab off ebay-or at least thats the one in the picture.I emailed the guy you bought yours from Scaf and he assures me thats the one i will receive-the ps32lab.I'm stoked-cant wait to wire this in and get rid of the four wall-warts!!!


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## Scafremon (Dec 11, 2006)

Since posting last on this, I tested the actual outputs of the PS using a test meter. (At this time, the voltmeter on the unit is not displaying anything but a decimal point). The outputs tested fine and constant. Pyramid is sending me out a new voltmeter, which I will solder in. This should solve the problem.

Assuming it does fix the issue, I will be happy with this purchase. A true lab grade power supply is not really required for my slot car hobby, although if you can get one for a similiar cost, it can't hurt.

I took an old outdoor extension cord which I had previously hedge-trimmed in half, and am going to use this to connect the PS to my table. I connected banana plugs on one pair of ends, and ring connectors on the other. I wanted a heavy-duty cable for this, as it will be on the floor from the PS on a shelf.


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## Scafremon (Dec 11, 2006)

Meter received today, soldered it in, and everything works.

One thing I noticed is that there is a dial on the back of the voltmeter, that you can turn to calibrate the display voltage. When I installed the new meter and compared the output with a test meter, it was .5 volts off. Turned the dial until they synched up. Just a note to anyone else who gets one of these Pyramid PS and wants to double check the voltage reading.


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## Ragnar (Aug 22, 2006)

I have used the PS32Lab for all of my motor testing, and I have fuund it to be as or more accurate than the $300. plus power supplies.

Tom


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## RiderZ (Feb 19, 2007)

*P/s!*

The UPS man brought my Pyramid PS32Lab P/S today!!! Got it all wired in off two-four slot power blocks.Works very well-i really like the adjustability.What a world of difference from the wall-warts!


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## BRS Hobbies (Feb 16, 2006)

Upgrading the controllers and the power supply really optimize the racing experience. I have used a Pyramid and a Samlex power supply for about 5 years without any problems. 

RiderZ,
Your track looks great! What size is the table?

Best regards,
Brian


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## RiderZ (Feb 19, 2007)

Yeh the P/S and controllers make a much better racing experiance.My layout is on a 4'X11' table.From a little testing i've done i like to run magnet cars at 15-16V & Xtractions at around 12-13V.


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## HOSCLW2010 (Jan 6, 2010)

*Pyramid Ps30lab*

Anyone have a PYRAMID PS30LAB power supply for sale? Thanks.


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