|
Any what to look out for situations for this, besides matching voltages?
?
I took an Astron SS-30M that was not switched on and back fed 5-18VDC from a metered regulated bench supply to it. With initial switch on at 13.8V from the bench supply, the? "on" current was 200mA that soon dropped to 10mA. The volt meter on the SS-30M then read 13.8V. SS-30M analog amp meter still at zero to the eye.
?
From that test , it appears that no isolating diodes from SS-30 power supplies to common output would be required, and as long as the output voltages are equal, both supplies should carry half of the required current. It seems it would be best would be to use SS-30M supplies so the equal current draws can be confirmed visually, but not really necessary if equal voltages stay equal.?
?
If available, is it significantly important or just preferred to connect both? supplies voltage sensing leads?? The SS-30 supplies? do not have externally reachable sense wires, but if really needed, they could be brought outside the case.
?
John
?
?
|
Operating 2 supplies in parallel without isolating diodes works
until one power supply output shorts out, then takes both supplies
down..Isolating diodes should always be used or other method to
isolate the 2 power supplies in case of failure
On 4/18/2025 18:48 PM, John via
groups.io wrote:
toggle quoted message
Show quoted text
Any what
to look out for situations for this, besides matching
voltages?
?
I took an
Astron SS-30M that was not switched on and back fed 5-18VDC
from a metered regulated bench supply to it. With initial
switch on at 13.8V from the bench supply, the? "on" current
was 200mA that soon dropped to 10mA. The volt meter on the
SS-30M then read 13.8V. SS-30M analog amp meter still at zero
to the eye.
?
From that
test , it appears that no isolating diodes from SS-30 power
supplies to common output would be required, and as long as
the output voltages are equal, both supplies should carry half
of the required current. It seems it would be best would be to
use SS-30M supplies so the equal current draws can be
confirmed visually, but not really necessary if equal voltages
stay equal.?
?
If
available, is it significantly important or just preferred to
connect both? supplies voltage sensing leads?? The SS-30
supplies? do not have externally reachable sense wires, but if
really needed, they could be brought outside the case.
?
John
?
?
|
?
I've never done it, but I have a couple astron
supplies that have a third connection that is supposed if hooked in
parallel.? I don't know what it does.?
?
Butch Bussen WA0VJR butchb@...irlp
7135 allstar 56023 echolink 790800
----- Original Message -----
Sent: Friday, April 18, 2025 6:56 PM
Subject: Re: [repeater-builder] Placing Two Identical Regulated DC
supplies in Parallel
Operating 2 supplies in parallel without isolating diodes works until one
power supply output shorts out, then takes both supplies down..Isolating diodes
should always be used or other method to isolate the 2 power supplies in case of
failure
On 4/18/2025 18:48 PM, John via groups.io
wrote:
Any what to look out for
situations for this, besides matching voltages?
I took an Astron SS-30M that
was not switched on and back fed 5-18VDC from a metered regulated bench supply
to it. With initial switch on at 13.8V from the bench supply, the? "on"
current was 200mA that soon dropped to 10mA. The volt meter on the SS-30M then
read 13.8V. SS-30M analog amp meter still at zero to the eye.
From that test , it appears
that no isolating diodes from SS-30 power supplies to common output would be
required, and as long as the output voltages are equal, both supplies should
carry half of the required current. It seems it would be best would be to use
SS-30M supplies so the equal current draws can be confirmed visually, but not
really necessary if equal voltages stay equal.?
If available, is it
significantly important or just preferred to connect both? supplies
voltage sensing leads?? The SS-30 supplies? do not have externally
reachable sense wires, but if really needed, they could be brought outside the
case.
John
|
Is the PS isn’t built for it, there is always a challenge in balancing current. Even when using diode devices, one unit always supplies a greater portion of the current. ? There are a number of “commercial” supplies in the market that support paralleling, from 2 units to several. Who wants to spend $650 on an RS70M that “just” deliver 57A continuous? Especially if you can get 200A for less money? ? The key question, is are you looking for high availability, load sharing, or both? ? Lower cost units typically you droop current sharing. This type is frequently 1+1, though there are some (common) implementations that scale up to 4 units. ? Convection or forced air is often a consideration. Convection…. 12v units of 30A each are available up to 4 in droop configs. One item that can get you in this implementation is that a minimum amount of current is required, usually at least 5%, thus if you had 4 30A units in parallel, you’d need a continuous current draw of 6A (30A x 5% x 4). For uses such as 12V amps that key on and off, this doesn’t work. ? Forced air options are more widely available, however, they are noisy. Common options deliver up to 200A @ 12V for under $500. ? Matt AL0R ? ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of John via groups.io Sent: Friday, April 18, 2025 19:49 To: [email protected]Subject: [repeater-builder] Placing Two Identical Regulated DC supplies in Parallel ? Any what to look out for situations for this, besides matching voltages? I took an Astron SS-30M that was not switched on and back fed 5-18VDC from a metered regulated bench supply to it. With initial switch on at 13.8V from the bench supply, the? "on" current was 200mA that soon dropped to 10mA. The volt meter on the SS-30M then read 13.8V. SS-30M analog amp meter still at zero to the eye. From that test , it appears that no isolating diodes from SS-30 power supplies to common output would be required, and as long as the output voltages are equal, both supplies should carry half of the required current. It seems it would be best would be to use SS-30M supplies so the equal current draws can be confirmed visually, but not really necessary if equal voltages stay equal.? If available, is it significantly important or just preferred to connect both? supplies voltage sensing leads?? The SS-30 supplies? do not have externally reachable sense wires, but if really needed, they could be brought outside the case.
|
There’s an article on the Astron page at repeater-builder that walks you through it.?
On Fri, Apr 18, 2025 at 06:01 PM, Butch-tiny puppy wrote:
I've never done it, but I have a couple astron supplies that have a third connection that is supposed if hooked in parallel.? I don't know what it does.?
?
Butch Bussen WA0VJR butchb@...irlp 7135 allstar 56023 echolink 790800
|
I work for an industrial power supply manufacturer, in the engineering dept.? This is not a recommended configuration unless the power supplies are both designed for it.
?
You risk uneven load sharing which can overload one supply while the other does almost nothing.? The more heavily loaded supply could overheat or go into current limit.? This can happen with even very small voltage differences.... i.e., 12.00 vs. 12.05 volts.??
Despite the seemingly identical nature on paper, you can have large circulating currents between the supplies since there is almost no chance they will be perfectly voltage matched.? This wastes power and can damage internal components, especially if one supply is not designed to sink current.
?
If they are switching supplies, you can create feedback loops where the supplies may interact in strange ways, potentially causing oscillations or unstable behavior... there is nothing syncing the switching frequencies.
?
The supplies may have slightly different protection thresholds for overcurrent or overvoltage.? If one supply trips in a fault condition, that leaves the other supply to suddenly take the full load.? If you design things so one supply can take the full load to avoid this, then you really don't need two supplies.
?
Supplies may power up at slightly different rates which can cause temporary overcurrent conditions.
?
The supplies we manufacture are designed for parallel operation but to do this they have several sophisticated control boards, data communication between them, and very heavy duty buss bars connected between them to handle high current conditions and provide a very low resistance path between the outputs.
?
--
73,
Marlo
KA2IRQ
?
?
?
|
Thank you for the extensive information Marlo, and the other great replies also. It sure was tempting to do, until your reply, as these Astron SS-30 supplies have overvoltage, overcurrent, and overtemp protection, and the internal voltage sensor wires are right next to? the output terminals, which could have short low voltage drop leads between supplies.
?
John
On 04/19/2025 8:13 AM EDT Marlo Montanaro - KA2IRQ <ka2irq@...> wrote:
?
?
I work for an industrial power supply manufacturer, in the engineering dept.? This is not a recommended configuration unless the power supplies are both designed for it.
?
You risk uneven load sharing which can overload one supply while the other does almost nothing.? The more heavily loaded supply could overheat or go into current limit.? This can happen with even very small voltage differences.... i.e., 12.00 vs. 12.05 volts.??
Despite the seemingly identical nature on paper, you can have large circulating currents between the supplies since there is almost no chance they will be perfectly voltage matched.? This wastes power and can damage internal components, especially if one supply is not designed to sink current.
?
If they are switching supplies, you can create feedback loops where the supplies may interact in strange ways, potentially causing oscillations or unstable behavior... there is nothing syncing the switching frequencies.
?
The supplies may have slightly different protection thresholds for overcurrent or overvoltage.? If one supply trips in a fault condition, that leaves the other supply to suddenly take the full load.? If you design things so one supply can take the full load to avoid this, then you really don't need two supplies.
?
Supplies may power up at slightly different rates which can cause temporary overcurrent conditions.
?
The supplies we manufacture are designed for parallel operation but to do this they have several sophisticated control boards, data communication between them, and very heavy duty buss bars connected between them to handle high current conditions and provide a very low resistance path between the outputs.
?
--
73,
Marlo
KA2IRQ
?
?
?
|
I’m glad it was helpful John. ? I know there is some info out there on how to do it, and I’m not saying it can’t be done… just really not a recommended configuration. ? I work for TDK-Lamba in NJ, where we design and manufacture our Genesys and Genesys+ supplies.? I’m actually working on a new line of equipment for a customer and I literally pulled parallel kits from our assembly line yesterday to begin testing this exact configuration with both two and four parallel supplies. ? Granted, things are much smaller with fixed 12V supplies, but the principle is the same.? And even with remote sense hooked up, you risk a mis-match causing oscillation and noise as the supplies try to figure it out.? That’s not what you need in a radio/repeater scenario, especially with the load constantly changing as the transmitter goes on and off during a QSO.? We have oscilloscope pictures during dynamic load testing and the voltage spikes are crazy- all that needs to be suppressed, or at least accounted for.? Switching several amps as the load changes can easily cause voltage spikes over 100V for several micro-seconds on the supply output, and if the filter caps aren’t rated for that, you’ll only know it happened because of the smoke and the loud bang.? (Trust me, the caps will blow to protect any fuses in the circuit.)
If you have two supplies you were planning on using, I would honestly sell them and put the money towards one supply that can handle the load plus 25-50%.? Just my 2-cents. ? Good luck!! ? ?
toggle quoted message
Show quoted text
From: JOHN HASERICK <jhaserick84@...>
Sent: Saturday, April 19, 2025 8:29 AM
To: [email protected]; Marlo Montanaro - KA2IRQ <ka2irq@...>
Subject: Re: [repeater-builder] Placing Two Identical Regulated DC supplies in Parallel? Thank you for the extensive information Marlo, and the other great replies also. It sure was tempting to do, until your reply, as these Astron SS-30 supplies have overvoltage, overcurrent, and overtemp protection, and the internal voltage sensor wires are right next to? the output terminals, which could have short low voltage drop leads between supplies. On 04/19/2025 8:13 AM EDT Marlo Montanaro - KA2IRQ <ka2irq@...> wrote: I work for an industrial power supply manufacturer, in the engineering dept.? This is not a recommended configuration unless the power supplies are both designed for it. You risk uneven load sharing which can overload one supply while the other does almost nothing.? The more heavily loaded supply could overheat or go into current limit.? This can happen with even very small voltage differences.... i.e., 12.00 vs. 12.05 volts.??
Despite the seemingly identical nature on paper, you can have large circulating currents between the supplies since there is almost no chance they will be perfectly voltage matched.? This wastes power and can damage internal components, especially if one supply is not designed to sink current. If they are switching supplies, you can create feedback loops where the supplies may interact in strange ways, potentially causing oscillations or unstable behavior... there is nothing syncing the switching frequencies. The supplies may have slightly different protection thresholds for overcurrent or overvoltage.? If one supply trips in a fault condition, that leaves the other supply to suddenly take the full load.? If you design things so one supply can take the full load to avoid this, then you really don't need two supplies. Supplies may power up at slightly different rates which can cause temporary overcurrent conditions. The supplies we manufacture are designed for parallel operation but to do this they have several sophisticated control boards, data communication between them, and very heavy duty buss bars connected between them to handle high current conditions and provide a very low resistance path between the outputs.
|
John,
I think to give an intelligent answer, we also need to know the application.?? If this were a repeater, I would recommend that you just have one on the PA and one on everything else.
Marlo gave you a lot of good information.
I have paralleled supplies before.?? The issue with the ASTRON SS-30 is that it is not temperature stable.?? I have had most of mine drop voltage slightly when they warm up.?? But they drop at different rates.? Some would drop by as little as .1V with no load after becoming warm.?? If you were to parallel, I would recommend using some .1 ohm resistors in series with each (high wattage), and also a fuse 30A on each leg. ? This would help balance them better (it wouldn't be perfect, but much better).?? This is similar to what linear supplies do when they parallel series pass transistors.?? They each have emitter resistors to help balance the shared load.?? But then you will lose a little of your regulation (if that matters).
I still wouldn't recommend doing it, as there are much better options and even cheaper.? Like a modified Astec DS-550 which can deliver 50A.
Andy WJ9J On Sat, Apr 19, 2025 at 8:13?AM Marlo Montanaro - KA2IRQ via <ka2irq= [email protected]> wrote:
I work for an industrial power supply manufacturer, in the engineering dept.? This is not a recommended configuration unless the power supplies are both designed for it.
?
You risk uneven load sharing which can overload one supply while the other does almost nothing.? The more heavily loaded supply could overheat or go into current limit.? This can happen with even very small voltage differences.... i.e., 12.00 vs. 12.05 volts.??
Despite the seemingly identical nature on paper, you can have large circulating currents between the supplies since there is almost no chance they will be perfectly voltage matched.? This wastes power and can damage internal components, especially if one supply is not designed to sink current.
?
If they are switching supplies, you can create feedback loops where the supplies may interact in strange ways, potentially causing oscillations or unstable behavior... there is nothing syncing the switching frequencies.
?
The supplies may have slightly different protection thresholds for overcurrent or overvoltage.? If one supply trips in a fault condition, that leaves the other supply to suddenly take the full load.? If you design things so one supply can take the full load to avoid this, then you really don't need two supplies.
?
Supplies may power up at slightly different rates which can cause temporary overcurrent conditions.
?
The supplies we manufacture are designed for parallel operation but to do this they have several sophisticated control boards, data communication between them, and very heavy duty buss bars connected between them to handle high current conditions and provide a very low resistance path between the outputs.
?
--
73,
Marlo
KA2IRQ
?
?
?
|
Thanks for the 0.1 ohm with 30 A fuse suggestion Andy, as regulation is not critical.
?
I was thinking about using the SS-30s for a repeater power amp. One could be a Micor 75W amp that could be set back, if needed, to draw? 25A at 13.8V. The other could be a 270W 6M Henry amp that draws 33A at 13.8V.?
?
I had tried an Astron SS-50 on the Henry amp, but it went into overtemp shutdown on somewhat? long repeater use time. I replaced it with a MeanWell HRP-600-12 with no overtemp problems, however the MeanWell required over 5 ferrites on the A+ A- leads with the A- grounded for RF emissions to the case. The AC input was? already RF suppressed at the factory, apparently allowing MeanWell to say the supply meets FCC Class B emissions. The MeanWell switcher with the small fan running at at high RPM when full speed during transmitting, very? slow speed with no current draw, is apparently the reliability weak spot with that supply if the fan is forced to run long times at high speed. That is why I was favoring the idea of using the large, slower, quieter intermittent running fan on Astron SS-30.
?
Years ago the Astron SS-12 and the Astron SS-18 were tried to power radios on the bench about 75 ft away from our 6M repeater antenna. Both caused 6M repeater receiver intermod desense when the 6M TX came on, but a replacement SS-30 did not. Also recent spectrum analyzer sweeps showed the Astron SS-30 to be clean, the HRP600-12 without ferrites, spikes actually worse around 130 MHz than 6M with the pick up antenna about 4 ft away from the supplies and exposed power leads. The HRP-600 with ferrites and especially when enclosed in a repeater cabinet was then also clean when transmitting.
?
Another switcher that in the past that appeared clean without much filtering for repeater use was the Diamond GZV4000, RATED 40A continuous, so that might
be a possibility, but I forget if it has overvoltage, overtemp, and overcurrent protection.
?
So I am extra cautious about switchers, especially outside a shielded enclosure, particularly on a commercial site, as don't want to degrade the site and lose the privilege!?
?
John
?
?
On 04/19/2025 11:19 AM EDT wj9jrg via groups.io <wj9jrg@...> wrote:
?
?
John,
?
I think to give an intelligent answer, we also need to know the application.?? If this were a repeater, I would recommend that you just have one on the PA and one on everything else.
?
Marlo gave you a lot of good information.
?
I have paralleled supplies before.?? The issue with the ASTRON SS-30 is that it is not temperature stable.?? I have had most of mine drop voltage slightly when they warm up.?? But they drop at different rates.? Some would drop by as little as .1V with no load after becoming warm.?? If you were to parallel, I would recommend using some .1 ohm resistors in series with each (high wattage), and also a fuse 30A on each leg. ? This would help balance them better (it wouldn't be perfect, but much better).?? This is similar to what linear supplies do when they parallel series pass transistors.?? They each have emitter resistors to help balance the shared load.?? But then you will lose a little of your regulation (if that matters).
?
I still wouldn't recommend doing it, as there are much better options and even cheaper.? Like a modified Astec DS-550 which can deliver 50A.
?
Andy
WJ9J
On Sat, Apr 19, 2025 at 8:13?AM Marlo Montanaro - KA2IRQ via <ka2irq= [email protected]> wrote:
I work for an industrial power supply manufacturer, in the engineering dept.? This is not a recommended configuration unless the power supplies are both designed for it.
?
You risk uneven load sharing which can overload one supply while the other does almost nothing.? The more heavily loaded supply could overheat or go into current limit.? This can happen with even very small voltage differences.... i.e., 12.00 vs. 12.05 volts.??
Despite the seemingly identical nature on paper, you can have large circulating currents between the supplies since there is almost no chance they will be perfectly voltage matched.? This wastes power and can damage internal components, especially if one supply is not designed to sink current.
?
If they are switching supplies, you can create feedback loops where the supplies may interact in strange ways, potentially causing oscillations or unstable behavior... there is nothing syncing the switching frequencies.
?
The supplies may have slightly different protection thresholds for overcurrent or overvoltage.? If one supply trips in a fault condition, that leaves the other supply to suddenly take the full load.? If you design things so one supply can take the full load to avoid this, then you really don't need two supplies.
?
Supplies may power up at slightly different rates which can cause temporary overcurrent conditions.
?
The supplies we manufacture are designed for parallel operation but to do this they have several sophisticated control boards, data communication between them, and very heavy duty buss bars connected between them to handle high current conditions and provide a very low resistance path between the outputs.
?
--
73,
Marlo
KA2IRQ
?
?
?
?
?
|
John,
In retrospect, .1 ohm may be too high of a value.?? You might would rather have a .02 Ohm, that way 30A only drops .6V
Thanks
Andy
Thanks for the 0.1 ohm with 30 A fuse suggestion Andy, as regulation is not critical.
?
I was thinking about using the SS-30s for a repeater power amp. One could be a Micor 75W amp that could be set back, if needed, to draw? 25A at 13.8V. The other could be a 270W 6M Henry amp that draws 33A at 13.8V.?
?
I had tried an Astron SS-50 on the Henry amp, but it went into overtemp shutdown on somewhat? long repeater use time. I replaced it with a MeanWell HRP-600-12 with no overtemp problems, however the MeanWell required over 5 ferrites on the A+ A- leads with the A- grounded for RF emissions to the case. The AC input was? already RF suppressed at the factory, apparently allowing MeanWell to say the supply meets FCC Class B emissions. The MeanWell switcher with the small fan running at at high RPM when full speed during transmitting, very? slow speed with no current draw, is apparently the reliability weak spot with that supply if the fan is forced to run long times at high speed. That is why I was favoring the idea of using the large, slower, quieter intermittent running fan on Astron SS-30.
?
Years ago the Astron SS-12 and the Astron SS-18 were tried to power radios on the bench about 75 ft away from our 6M repeater antenna. Both caused 6M repeater receiver intermod desense when the 6M TX came on, but a replacement SS-30 did not. Also recent spectrum analyzer sweeps showed the Astron SS-30 to be clean, the HRP600-12 without ferrites, spikes actually worse around 130 MHz than 6M with the pick up antenna about 4 ft away from the supplies and exposed power leads. The HRP-600 with ferrites and especially when enclosed in a repeater cabinet was then also clean when transmitting.
?
Another switcher that in the past that appeared clean without much filtering for repeater use was the Diamond GZV4000, RATED 40A continuous, so that might
be a possibility, but I forget if it has overvoltage, overtemp, and overcurrent protection.
?
So I am extra cautious about switchers, especially outside a shielded enclosure, particularly on a commercial site, as don't want to degrade the site and lose the privilege!?
?
John
?
?
?
?
John,
?
I think to give an intelligent answer, we also need to know the application.?? If this were a repeater, I would recommend that you just have one on the PA and one on everything else.
?
Marlo gave you a lot of good information.
?
I have paralleled supplies before.?? The issue with the ASTRON SS-30 is that it is not temperature stable.?? I have had most of mine drop voltage slightly when they warm up.?? But they drop at different rates.? Some would drop by as little as .1V with no load after becoming warm.?? If you were to parallel, I would recommend using some .1 ohm resistors in series with each (high wattage), and also a fuse 30A on each leg. ? This would help balance them better (it wouldn't be perfect, but much better).?? This is similar to what linear supplies do when they parallel series pass transistors.?? They each have emitter resistors to help balance the shared load.?? But then you will lose a little of your regulation (if that matters).
?
I still wouldn't recommend doing it, as there are much better options and even cheaper.? Like a modified Astec DS-550 which can deliver 50A.
?
Andy
WJ9J
On Sat, Apr 19, 2025 at 8:13?AM Marlo Montanaro - KA2IRQ via <ka2irq= [email protected]> wrote:
I work for an industrial power supply manufacturer, in the engineering dept.? This is not a recommended configuration unless the power supplies are both designed for it.
?
You risk uneven load sharing which can overload one supply while the other does almost nothing.? The more heavily loaded supply could overheat or go into current limit.? This can happen with even very small voltage differences.... i.e., 12.00 vs. 12.05 volts.??
Despite the seemingly identical nature on paper, you can have large circulating currents between the supplies since there is almost no chance they will be perfectly voltage matched.? This wastes power and can damage internal components, especially if one supply is not designed to sink current.
?
If they are switching supplies, you can create feedback loops where the supplies may interact in strange ways, potentially causing oscillations or unstable behavior... there is nothing syncing the switching frequencies.
?
The supplies may have slightly different protection thresholds for overcurrent or overvoltage.? If one supply trips in a fault condition, that leaves the other supply to suddenly take the full load.? If you design things so one supply can take the full load to avoid this, then you really don't need two supplies.
?
Supplies may power up at slightly different rates which can cause temporary overcurrent conditions.
?
The supplies we manufacture are designed for parallel operation but to do this they have several sophisticated control boards, data communication between them, and very heavy duty buss bars connected between them to handle high current conditions and provide a very low resistance path between the outputs.
?
--
73,
Marlo
KA2IRQ
?
?
?
?
?
|
John,
?
What load are we trying to supply?? How much total current?
?
--
73,
Marlo
KA2IRQ
?
|
Hello Marlo,
?
If used for the Henry Amp, it would be 33Amps at 14.1V. I am going to try just for curiosity, two Astron SS-30M supplies in parallel and compare with the existing repeater HRP-600 12. First I will try no equalizing resistors and monitor currents and voltage as it keys , unkeys, and over different TX times. then take it from there and let the actual results be known for all to benefit. It certainly would be great if it can be made to work with 2 side by side rack mounted units at least for those particular supplies.
?
One of the other nearby 6M repeaters uses a different Astron model switcher with 4 switchers packaged together in parallel by Astron with each unit drawing on TX between 9 and 9.5A? at 13.8V for a 300W? TE Systems amp. Been working for over 5 yrs, but I am a bit concerned that it did not have overvoltage protection. I do not see that model supply still being sold by Astron. If I remember correctly, the 4 supplies were interconnected to a common voltage? control bus, and monitoring of individual supply currents was done one at a time with a rotary switch. That got me thinking about joining the SS-30's.
?
John
On 04/20/2025 8:34 AM EDT Marlo Montanaro - KA2IRQ <ka2irq@...> wrote:
?
?
John,
?
What load are we trying to supply?? How much total current?
?
--
73,
Marlo
KA2IRQ
?
|
I've been running 4 Meanwell switchers (12VDC @ 29 amps) in series for well over 10 years to provide 50 volts to my 6 & 2 meter solid state KW amps. They haven't let me down even after hours and hours of 1 minute TX and 1 minute RX)
Ken
------------------------------------------------------------------------------
President and CTO - Arcom Controllers
Makers of repeater controllers and accessories
Phone: (503) 678 6182
Authorized Dealers for Kenwood and Telewave.
We offer complete turn-key repeater packages!
"We don't just make 'em. We use 'em!"
[]
|
All good- but seems like it is over complicated when you can get a
single 50 or 60amp supply to do the job probably for less money than
2, 3 or 4 smaller power supplies.
73,
Marlo
KA2IRQ
On 4/20/2025 2:16 PM, JOHN HASERICK
wrote:
toggle quoted message
Show quoted text
Hello
Marlo,
?
If used
for the Henry Amp, it would be 33Amps at 14.1V. I am going to
try just for curiosity, two Astron SS-30M supplies in parallel
and compare with the existing repeater HRP-600 12. First I
will try no equalizing resistors and monitor currents and
voltage as it keys , unkeys, and over different TX times. then
take it from there and let the actual results be known for all
to benefit. It certainly would be great if it can be made to
work with 2 side by side rack mounted units at least for those
particular supplies.
?
One of
the other nearby 6M repeaters uses a different Astron model
switcher with 4 switchers packaged together in parallel by
Astron with each unit drawing on TX between 9 and 9.5A? at
13.8V for a 300W? TE Systems amp. Been working for over 5 yrs,
but I am a bit concerned that it did not have overvoltage
protection. I do not see that model supply still being sold by
Astron. If I remember correctly, the 4 supplies were
interconnected to a common voltage? control bus, and
monitoring of individual supply currents was done one at a
time with a rotary switch. That got me thinking about joining
the SS-30's.
?
John
On 04/20/2025 8:34 AM EDT Marlo Montanaro - KA2IRQ
<ka2irq@...> wrote: ?
?
John,
?
What load are we trying to supply?? How much total
current?
?
--
73,
Marlo
KA2IRQ
?
|
The LDMOS community seems to have settled on Eltek Flatpack2 series either 48/2000 which does 53.5V at 37A continuous or the 48/3000 which does 53.5V at 55A continuous. Both of these show up on eBay for under $75 and they are tiny for what they do.?
?
For the original post I agree that a single Meanwell with some ferrites on the output leads is reasonably priced and have proven to be very reliable.?
|
I have a Duracomm DPS-75 Power Supply on my collecting dust. Got it for a good price after our club had an Astron fail on one of our repeaters. County Radio Shop loaned us a DuraComm DPS-55 (Amp) . We bought one
for $100 plus tax that has been in continuous use for 3 years now. The nice things about the DuraComms is they put out what they have full rated current available ALL the time.
Dave, AB2WL
|
For our club site, I consolidated all the 12V loads onto a single power system, using
ICT N+1 Power system.??? Same supplies as what Daniels/Codan/Zetron supplied with
their units.?? Provides the redundancy, alarming, etc.? Yes, pricier than an Astron, but given
the site is almost 12,000', it only takes the savings of one or two extra trips to trouble shoot
power problems to make it worthwhile.?? Running for 7 or 8 years so far with nary a hiccup.
In all my years of getting paid to do radio/electronic repair, an extremely high percentage of the
problems were power & power supply related.? Investing in a good power system pays off in the long run.
Making the investment in good station style batteries also pays off.? Yes they are several times
the cost of regular deep cycle lead acid, but they will run for 15-20 years, so in balances out
over time.
You can pay up front, or you can spend your money on gasoline, tires, and wear and tear getting
to/from your site.?? For those of us that have to get to mountain tops, it pays to do it well the first
time.?? And just like generators, remember to look closely at the specs for your power supply if you
are operating at Altitude, most specs are only to 10K or lower.
Chuck?? n0nhj
Glenwood Springs, CO? USA
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At 4/20/2025 11:24 AM, you wrote:
I've been running 4 Meanwell
switchers (12VDC @ 29 amps) in series
for well over 10 years to provide 50 volts to my 6 & 2 meter solid
state KW amps. They haven't let me down even after hours and hours of
1 minute TX and 1 minute RX)
Question: what happens if the 48 V output is shorted to ground??
Most any single supply could withstand that, but they really don't like
having their + output taken 36 V below the - output.? Might end up
with 3 blown power supplies.
Bob NO6B
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I suppose it's possible but after 10 years of hard use, they still seem
pretty happy. Besides, if push comes to shove, replacements are under
$30. I can line with that.
Ken
At 03:21 PM 4/20/2025, you wrote:
toggle quoted message
Show quoted text
At 4/20/2025 11:24 AM, you
wrote:
I've been running 4 Meanwell
switchers (12VDC @ 29 amps) in series
for well over 10 years to provide 50 volts to my 6 & 2 meter solid
state KW amps. They haven't let me down even after hours and hours of
1 minute TX and 1 minute RX)
Question: what happens if the 48 V output is shorted to ground??
Most any single supply could withstand that, but they really don't like
having their + output taken 36 V below the - output.? Might end up
with 3 blown power supplies.
Bob NO6B
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