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AC to DC Power Supply

I know very little about electronics. I need an ac-dc regulated 24 vdc 5 amp minimum (preferably, but 4 amp may do). I found a Lambda data sheet at:

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The model I am looking into is JWS100-24/A. They list a maximum current of 4.5 amps. Does anyone know if this is supposed to be a surge current, or the maximum that can be drawn continuously? One supplier (Allied Electronics) states "24 volts @ 3.6 amps" yet the Lambda data sheet says 4.5 amps max which makes me think the 4.5 amps is a surge current.

I need a regulated power supply, but the data sheet on the Lambda power supply does not indicate if it is regulated by using such terms as "regulated" or "closed loop". Can one tell from the data sheet if it is regulated? When I ask this question to the people (women) at Lambda, all they do is send me the data sheet and say they hope this helps (on two occasions).

One individual on another list recommended a 24 volt 6.5 amp switching power supply at Alllied Electronics:

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A second individual said from experience to use a better power supply from companies like SOLA, LAMBDA, VOGEN, and TRACO and made reference to derating curves. The Lambda power supply mentioned above is a lot more expensive than the Allied Electronics power supply: over $200 vs about $35. Is the higher price for the Lambda really worth it? It will be used to drive two servo motors on a telescope and I need good and consistent telescope tracking accuracy. It seems like I am having a hard time finding a 24 vdc power supply at the amp rating I need in the better quality brands, but it seems cheaper ones, like the Allied Electronics one, are easier to find. I do not know what to think.

Stan

Reply to
Stanley A. Gorodenski
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Stan, take a look at the JWS100 series spec at

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It shows that this PS will run at full load at temps from -10C to +50C in a standard mounting configuration. It can go up to +60C with derating, (see spce sheet). See the spec sheet for mounting configurations that are allowed. The 4.5A current rating is a continuous rating. Overcurrent protection kicks in at 4.72A. Yes, the PS is very definitely regulated, and can be remotely sensed. That means that the power supply can regulate the voltage right at the load, automatically compensating for voltage drop in the wiring between the PS and the load. Of course, it can also be locally sensed (the default configuration), which means that the voltage is regulated only to the terminals on the PS, and does not compensate for wiring voltage drop.

The Globtek unit appears to be adequate for your needs, at much lower cost. However, it doesn't have the operating temperature range that the Lambda unit has.. only from 0C to 40C. If your environment can meet that temp range, then go with the Globtek unit. If you need the extra comfort on the high temp end, then spring for the cash and get the Lambda unit. See the spec sheet at

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Again, the current rating is continuous.

Hth,

--
Dave M
MasonDG44 at comcast dot net  (Just subsitute the appropriate characters in
the address)

Never take a laxative and a sleeping pill at the same time!!
Reply to
Tweetldee

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Stan, take a look at the JWS100 series spec at

formatting link
It shows that this PS will run at full load at temps from -10C to +50C in a standard mounting configuration. It can go up to +60C with derating, (see spce sheet). See the spec sheet for mounting configurations that are allowed. The 4.5A current rating is a continuous rating. Overcurrent protection kicks in at 4.72A. Yes, the PS is very definitely regulated, and can be remotely sensed. That means that the power supply can regulate the voltage right at the load, automatically compensating for voltage drop in the wiring between the PS and the load. Of course, it can also be locally sensed (the default configuration), which means that the voltage is regulated only to the terminals on the PS, and does not compensate for wiring voltage drop.

The Globtek unit appears to be adequate for your needs, at much lower cost. However, it doesn't have the operating temperature range that the Lambda unit has.. only from 0C to 40C. If your environment can meet that temp range, then go with the Globtek unit. If you need the extra comfort on the high temp end, then spring for the cash and get the Lambda unit. See the spec sheet at

formatting link
Again, the current rating is continuous.

Hth,

--
Dave M
MasonDG44 at comcast dot net  (Just subsitute the appropriate characters in
the address)

Never take a laxative and a sleeping pill at the same time!!
Reply to
Tweetldee

Dave, Thanks for looking at this and answering my questions. It appears, based on the operating temperatures, the Lambda is better suited for my need. The Globtek's lower limit of 0 degrees is too high for my need. One individual in another list said: "The current handling and regulation is useless if it does not specify a derating curve. Most I bought from other brands derates by as much as 20-35% in current rating between

10-60Celsius. Most manufacturers derating curves are bogus and you have to learn the hard way. I learnt the hard way." This individual uses SOLA and recommends it as well as Lambda. He said Lambda is good but costs more. Initially I could not find a SOLA that would meet my needs (and SOLA has not answered my week old email message) but I am having better success now. Maybe I can find one that does not cost over $200.

Thanks for the link to the Lambda data sheet. I had run across this in my searches, but could not find it again. I believe the JWS100 series includes the JWS100-24/A power supply that was mentioned in my original post, but I notice in the data sheet that line 10 "Output Voltage Range" shows 8.9~9.9 V. I do not know how this relates to the output voltage of

24V.

Stan

Tweetldee wrote:

Reply to
Stanley A. Gorodenski

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