I just received a TeraDak U9 linear power supply to replace the iPad power supply I was using to power the Blitzortung blue board. It was a little costly, but it did cut down on the noise pretty good, as shown on the magenta E-field channel in the attached pictures.
I'm not sure if it really makes a big difference in accuracy of the system, but I'm pleased with the results.
(2017-08-30, 18:24)JupiterJoe Wrote: I just received a TeraDak U9 linear power supply to replace the iPad power supply I was using to power the Blitzortung blue board. It was a little costly, but it did cut down on the noise pretty good, as shown on the magenta E-field channel in the attached pictures.
I'm not sure if it really makes a big difference in accuracy of the system, but I'm pleased with the results.
Can you show how the voltage signal from the power supply looks like?
Menu "Blitzortung.org Controller" -> "Signals" tab -> "Signal Tools" -> "Sampling:" -> "Channel: V_in"
2017-08-30, 20:47 (This post was last modified: 2017-08-30, 20:54 by JupiterJoe.)
Here you go.
It seems lower on that than it does from the controller status page. I wonder why this is? Is this too low? Their website says output voltage is adjustable, but I'm not sure about that.
At least you aren't under power, but I don't know if over is good either... I wonder if it makes any difference?
I found that the USB voltage can't be adjusted on the unit I got, but there's another DC output that can be. I tested that one, and it's 5 volts on the nose. I just need to get an adapter for the plug that will connect to a USB plug. (Already have one on order)
(2017-08-31, 01:23)JupiterJoe Wrote: At least you aren't under power, but I don't know if over is good either... I wonder if it makes any difference?
I found that the USB voltage can't be adjusted on the unit I got, but there's another DC output that can be. I tested that one, and it's 5 volts on the nose. I just need to get an adapter for the plug that will connect to a USB plug. (Already have one on order)
What kind of power supply are you using?
This will handle all the required stuff.... https://www.powerstream.com/AC-1898.htm
Many of us use this little jewel... you just need to hardwire a mini-usb connector to it,
since it doesn't come with one...,. set it for 5 volts, tape down that selection switch, and rock on...
$15.25 plus shipping.... I've got a house full of 'em.
supplies plenty of current, regardless of the voltage you 'signal' page displays... works fine.
Overvoltage ain't good... down to about 4.25 should work, but I wouldn't run mine that low!!!! Not for long!
don't let it go over about 5.25....If I'm below about an indicated signals page voltage of 4.65-4.75 something is likely amiss... not enough current from wall wart, or at the margin, for example. if you've got a good, current rated supply, it should regulate at source fine.
See the specs on that 1898.... the source input on my BLUE at 115V right now is showing 4.95 volts with DVM, signals page is indicating 4.55... (i've a pre-release controller with piggy-back power supply mod board hung on... ).... My Red is on the button at 5.0 source, and 4.75 on signal page.
2017-08-31, 08:35 (This post was last modified: 2017-09-02, 09:23 by kriu.)
(2017-08-31, 01:23)JupiterJoe Wrote: What kind of power supply are you using?
The previous chart is from the power supply Samsung 5V, 2.0A (from the Samsung Galaxy S2 tablet).
Below are charts from another power supply: Samsung 5V, 1A (from Samsung Galaxy S4 mini smartphone).
The voltage often jumps as shown in Figure 2. Despite this, this new power supply seems better.
I have checked my power supply, and sometimes it also showes this jump in the voltage. Another one had a similar behaviour, so it seems to be a bug of all these switching power supplies! Unfortunately, I threw away my nice linear 5V power supplies some time ago... Thought I would never again need them...
Are you sure the voltage jumps aren't just a feature of the supplies regulation and changes in load? Looking at my system there are longish periods of "noise" at about 50 mV peak to peak with section of jumps of about 20 mV P-P. the "jumps" may coincide with the detection of strikes, and thus the sending of data and flashing of several LEDs.
Both these images are the same supply, without inline filter:
With inline filter:
The controller objected to the unfiltered supply but is very happy on the filtered. Vertical resolution of 1 V/div.
(2017-09-11, 14:52)pasense Wrote: Any suggestion for low-noise power supplies which are for sale here in Europe (and which are affordable)?
Maybe apply a suitable, simple low pass LC filter?
That is all the inline filter above that effectively kills the noise from the supply. Still have the "spare" PCB if anyone would like it. Takes a couple of torids from Amazon/eBay with provision for two capacitors on the in and out side.
(2017-09-11, 14:52)pasense Wrote: Any suggestion for low-noise power supplies which are for sale here in Europe (and which are affordable)?
Maybe apply a suitable, simple low pass LC filter?
That is all the inline filter above that effectively kills the noise from the supply. Still have the "spare" PCB if anyone would like it. Takes a couple of torids from Amazon/eBay with provision for two capacitors on the in and out side.
Could you show us a picture of it and where it fits, i.e. will it fit inside the case for Blue somewhere, or is it a separate "box?" Simple Circuit Diagram?
Or is it on the output of a PSU, Would it fit in the box with a small linear PSU. I am waiting for components to build a small linear PSU hopefully it won't
have too much noise at the frequencies of interest.
2017-09-22, 23:14 (This post was last modified: 2017-09-22, 23:17 by allsorts.)
[quote pid='15696' dateline='1505725678']
Could you show us a picture of it and where it fits, i.e. will it fit inside the case for Blue somewhere, or is it a separate "box?" Simple Circuit Diagram?
Or is it on the output of a PSU, Would it fit in the box with a small linear PSU. I am waiting for components to build a small linear PSU hopefully it won't
have too much noise at the frequencies of interest.
[/quote]
A half decent linear supply won't need a filter...
There is a picture of my filter to the left of the naked PoE splitter. I think there are some more somewhere showing my installed controller, but I can't kick the forum search into finding that thread....
The operating frequency is listed as 47 to 63 kHz, but there is no mention of how much that appears at the output separate from the overall voltage variation.
I hope this is of some use.
Thanks, but this info was already available at Amazon, I should have been more specific with the question!
Here it is: the data sheet gives the noise with 80 mV pp maximum, but does anybody know how that is in reality? Does anybody have a hands-on experience with this power supply together with system blue?
If it really does have 80 mV of 50 kHz (+/-) on the output it might be too noisy for a blue controller. The TL-POE10R I use to power mine had about 100 mV P-P noise and the controller wasn't happy. The simple two toroids and capacitors filter cured that though reducing the noise to 5 mV P-P (if the V_in monitor on the signals page of a controller is to be believed).
(Scale of 0.5V - just like you).
