Made a power supply

[Steve W]

Obviously this is not approved by anyone and should never be used for anything important.

I finally finished my power supply to replace my previous 30V 30A adjustable supply(which really wasn't fond of both 30V and 30A at the same time)

Contents:

1 x 27V 37A 1000W power supply

1 Inlet/Switch/Fuse

1 Amp/Volt Meter, 50A

2 Binding Posts

1 Horribly designed 3d printed 'case'

4 3D Printed Feet

1 Of the Finest Pelican Clone Cases(From Harbor Freight) There isn't enough room for ventilation, it can't be used in this small of a case it's just for transport.

The previous cables from the adjustable supply(which is a couple lugs to a SB175 connector, designed to let me use a single plane side connector and swap the other end between this supply and battery clamps and anything else I might need) The SB175 to Ground Power cable is not pictured, as it's still at the hangar.

So far, initial testing puts the half load ripple at 500mV, not great but decent enough.

Takeaways: took way too long to get the stupid case right, should have added another inch or so for wiring. Should probably have used PowerPole or something else instead of binding posts. 

 

Edited August 18, 2019 by Steve W

[N201MKTurbo]

I bought one of those cheap Chinese V, A meters on EBay to do the ELA on my airplane. 100 Amp.

I checked the shunt against a Keysight power supply and measured the shunt with an HP 3451.

I was surprised that it was so accurate. At 10 amps it was off by 5 ma.

I didn’t use the meter, just the shunt.

[Steve W]

37 minutes ago, N201MKTurbo said:

I bought one of those cheap Chinese V, A meters on EBay to do the ELA on my airplane. 100 Amp.

I checked the shunt against a Keysight power supply and measured the shunt with an HP 3451.

I was surprised that it was so accurate. At 10 amps it was off by 5 ma.

I didn’t use the meter, just the shunt.

My current Amazon purchase that shouldn't work as well as it does is these IC clips, sure Pomona sells a set of 10 for $600 with much better ergonomics, but for my purposes $20 is a much more useful price. Now if I can just get the bootloader loaded so I can stop with the clips.

[EricJ]

Lab stuff these days is crazy good bang for the buck.    A good spectrum analyzer used to be $50k, the last one I bought was <$1k and has better specs and is portable (USB).   

[N201MKTurbo]

1 hour ago, Steve W said:

My current Amazon purchase that shouldn't work as well as it does is these IC clips, sure Pomona sells a set of 10 for $600 with much better ergonomics, but for my purposes $20 is a much more useful price. Now if I can just get the bootloader loaded so I can stop with the clips.

Those are sweet. I wish I did that stuff these days. I spent 20 years doing embedded design, both hardware and software. Now I just build industrial automation systems for the defense and semiconductor industry.  

[bradp]

I just got an Astron manual adjustment (limited) linear supply used on eBay.  Thing is a beast. 

[FloridaMan]

On 8/17/2019 at 9:24 PM, Steve W said:

Obviously this is not approved by anyone and should never be used for anything important.

I finally finished my power supply to replace my previous 30V 30A adjustable supply(which really wasn't fond of both 30V and 30A at the same time)

Contents:

1 x 27V 37A 1000W power supply

1 Inlet/Switch/Fuse

1 Amp/Volt Meter, 50A

2 Binding Posts

1 Horribly designed 3d printed 'case'

4 3D Printed Feet

1 Of the Finest Pelican Clone Cases(From Harbor Freight) There isn't enough room for ventilation, it can't be used in this small of a case it's just for transport.

The previous cables from the adjustable supply(which is a couple lugs to a SB175 connector, designed to let me use a single plane side connector and swap the other end between this supply and battery clamps and anything else I might need) The SB175 to Ground Power cable is not pictured, as it's still at the hangar.

So far, initial testing puts the half load ripple at 500mV, not great but decent enough.

Takeaways: took way too long to get the stupid case right, should have added another inch or so for wiring. Should probably have used PowerPole or something else instead of binding posts. 

 

You should buy a k40 laser cutter on eBay for $300-350 if you’re going to be making boxes. You could cut the sides of that think in less time than it would take your 3D printed to warm up. 

[Steve W]

10 hours ago, FloridaMan said:

You should buy a k40 laser cutter on eBay for $300-350 if you’re going to be making boxes. You could cut the sides of that think in less time than it would take your 3D printed to warm up. 

Yea, but then you buy a K40, find out that the controller is generally disliked, buy a controller, realize that the 'digital' style control panel isn't really that great and the new controller has some discrete inputs and you have to 3d print a new control panel because you don't yet have a working laser cutter, there are no lid switches, should really setup active cooling for the coolant loop, the fume extraction sucks and a future project is to make an adjustable Z table.  And it still needs alignment. Not to mention I've gotten really good designing 3d printed boxes.

 

On the plus side, at least there's not a CNC router purchased with no electronics waiting for its controller and drivers... oh, wait.

 

Edited August 26, 2019 by Steve W

[FloridaMan]

31 minutes ago, Steve W said:

Yea, but then you buy a K40, find out that the controller is generally disliked, buy a controller, realize that the 'digital' style control panel isn't really that great and the new controller has some discrete inputs and you have to 3d print a new control panel because you don't yet have a working laser cutter, there are no lid switches, should really setup active cooling for the coolant loop, the fume extraction sucks and a future project is to make an adjustable Z table.  And it still needs alignment. Not to mention I've gotten really good designing 3d printed boxes.

 

On the plus side, at least there's not a CNC router purchased with no electronics waiting for its controller and drivers... oh, wait.

 

Looks like my office. I’ve been through some of those same steps. I didn’t want to have to take trips to the shop between iterations and bought one of those Chinese CNC machines and it sits in the corner just like yours. 

The laser, however, gets a ton of use. I use K40 Whisperer with the stock controller board and it works great. If you have to replace the tube at some point, I recommend not cutting the red wire just after turning it off. That got my attention.