Hello I have A Astron RS-70A power supply. The output Volts is currently 13.8Volts. Is there a pot somewhere inside the power supply to adjust the voltage output? I would like to get 15volts out.
Thanks
Thanks
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Astron RS-70A power supply
- Thread starter Drifter
- Start date
Check your manual. I have the 50 amp models so the adjustment might be the same. With the top off, near the front top is a small horizontal board, on the underside is a small notched half wheel that will allow you to make the adjustment. I'm not sure how much more voltage you will be able to get out of it.
I got home. Unplugged it, took the top off, found the board. I had to discharge the caps and remove the board from the cap. buy removing the two screws. I was able see the thumbwheel and adjust it to get 14.5 volts out. I am happy.
Thanks for the help.
Thanks for the help.
!! Glad I was able to help.
I got home. Unplugged it, took the top off, found the board. I had to discharge the caps and remove the board from the cap. buy removing the two screws. I was able see the thumbwheel and adjust it to get 14.5 volts out. I am happy.
Thanks for the help.
Let me see.......
Increase of 7/10 of one volt @ 70 amps equals 49 more watts capability
Efficiency of your load, 50%; net difference is 24.5 watts more output.
Getting 25 more watts out of a 100 watt radio, useless!
Running 25 more watts into your previously saturated SS device, senseless.
Man with Golden Screwdriver knowledge, Priceless!
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it would be nice if it was that simple,
about the only thing you can say is he would have 49w less power wasted as heat in the pass transistors @70amp,
we dont know the load impedance, current, voltage transformation ratio or the efficiency of the device been used so anything more is speculation.
about the only thing you can say is he would have 49w less power wasted as heat in the pass transistors @70amp,
we dont know the load impedance, current, voltage transformation ratio or the efficiency of the device been used so anything more is speculation.
if you're using such a power supply to run a class-C amplifier, you can just tap the DC straight off the big honkin blue capacitor, which bypasses the voltage regulator completely.
The voltage will be unregulated, meaning it could be up to 18volts under no load, and drop down to maybe 15volts under full load. You could never power a radio from that, but a class C amp would be fine with it. You also wouldn't have any loss from the pass transistors since no current is running thru them.
The voltage will be unregulated, meaning it could be up to 18volts under no load, and drop down to maybe 15volts under full load. You could never power a radio from that, but a class C amp would be fine with it. You also wouldn't have any loss from the pass transistors since no current is running thru them.
That's certainly one option. Another would be to replace the 'non-working' thermostat to one with a lower temp. rating. Guess it just depends on if you are willing to have the fan running all the time or not, and finding the 'thermostat' thingy at a reasonable cost.
Just for 'grins'.
I am using a 70+ amp power supply made something like 15-20 years ago (home-brew, no I didn't build it). It doesn't get hot, has no fan (one of them "when I get around to it" things, makes no noise besides the click of the switch when I turn it on. The only time it doesn't put out the expected voltage/current is when the power goes off or I turn it off. Not 'pretty', doesn't 'match' anything, and quite frankly, I couldn't care less. Built by 'Walt Williams' (not around anymore) and seriously doubt if it can be matched by any commercially made power supply, and ooooh was the price 'right'! {I'm looking for another one if there are any available used. Hint hint! Cheap, naturally. Been afraid to find out what the actual output capabilities are, besides I don't need an electric welder.} Sound like I'm bragging? Dang right! One of the very few instances where I got better than I expected.
- 'Doc
Raining again. Hell with cutting grass, anyone wanna buy some rice?
Just for 'grins'.
I am using a 70+ amp power supply made something like 15-20 years ago (home-brew, no I didn't build it). It doesn't get hot, has no fan (one of them "when I get around to it" things, makes no noise besides the click of the switch when I turn it on. The only time it doesn't put out the expected voltage/current is when the power goes off or I turn it off. Not 'pretty', doesn't 'match' anything, and quite frankly, I couldn't care less. Built by 'Walt Williams' (not around anymore) and seriously doubt if it can be matched by any commercially made power supply, and ooooh was the price 'right'! {I'm looking for another one if there are any available used. Hint hint! Cheap, naturally. Been afraid to find out what the actual output capabilities are, besides I don't need an electric welder.} Sound like I'm bragging? Dang right! One of the very few instances where I got better than I expected.
- 'Doc
Raining again. Hell with cutting grass, anyone wanna buy some rice?
Is it possible to get WALT's Schematics of your powers upply and build one!? Or draw up the schematic from the one you have???
Cheers KF0SPG
Cheers KF0SPG
Or you could save yourself all the hassle and buy a brand new 36 Amp Megawatt supply online. Not much bigger than a couple packs of smokes, totally silent, no RFI, and packs a punch. It is also way more efficient than the old "iron" supplies, meaning you will use less electrical power for the same output.
There are other versions with more amperage as well.
$74 US on ebay right now.
I've had mine running 24/7 for two years powering my radios and amps and it's worked flawlessly.
There are other versions with more amperage as well.
$74 US on ebay right now.
36 Amp @90% Duty Cycle 13.8V HAM Radio Power Supply 10-15.5 Volts 12 MegaWatt® 685256290230 | eBay
Highly filtered for no RF hash. It will cold start and hold up to a 36 amp load. This unit has a built in cooling fan. It operates on 120 volts AC or 220 volts AC, 47Hz to 63Hz. This makes this unit much lighter, smaller and less likely to over heat and malfunction.
www.ebay.com
I've had mine running 24/7 for two years powering my radios and amps and it's worked flawlessly.
Unless you have a line on a cheap transformer, large heat sink and a dozen high-current power transistors you won't save money building a linear-regulated power supply with the traditional heavy 60-Hz power transformer. Pretty sure that's what he's describing above. Consider also that if your protection circuits aren't right, you can fry a radio in the blink of an eye if the regulator circuit fails. The Megawatt models contain protection from both current overload and protection from spewing out dangerously-high voltage. The radio tends to be worth more than the power supply. Just consider it cheap insurance.
73
73