Tim,
These are just spares I had from an earlier order. Stock is limited. Hence I think Noel set a limit. I expect most of the price is the postage.
Mike
RT5047 U3 and U4
Re: RT5047 U3 and U4
Hi,
I can only get one at a time....
"You cannot add another "LNB supply PCB for BATC Advanced receiver" to your basket. "
Oh I see - they are limited by the supply.
As for the soldering well its time to try out my new Chinese Hot Air soldering gun. I now need some proper solder paste...
I'll give it a go but a standard soldering Iron would not work I am guessing from the look of things.
Mike
I can only get one at a time....
"You cannot add another "LNB supply PCB for BATC Advanced receiver" to your basket. "
Oh I see - they are limited by the supply.
As for the soldering well its time to try out my new Chinese Hot Air soldering gun. I now need some proper solder paste...
I'll give it a go but a standard soldering Iron would not work I am guessing from the look of things.
Mike
Re: RT5047 U3 and U4
>>I'll give it a go but a standard soldering Iron would not work I am guessing from the look of things.
I used an Antex CS18 with a 2mm bit for the main and LNB boards and it was fine.
Brian
I used an Antex CS18 with a 2mm bit for the main and LNB boards and it was fine.
Brian
Re: RT5047 U3 and U4
I had a conversation with G4KLB a few months ago about the RT5047 and made some notes:
"Farnell have 4 suffix versions: NULL, A, B and BF.
NULL 45ms activation, no fault output
A 45ms activation, fault output
B 6ms activation, no fault output
BF 6ms activation, fault output
BF seems the best, as long as the LNB inrush current doesn't cause it to keep tripping and preventing a startup. I seem to remember that the Octagon OTLSO causes my Pace MSS508 to flash its SHORTED screen briefly, but if that's what was used for the MT MK2 add-on board, it must be OK".
Farnell is on a go-slow at the moment, but I checked earlier and only the B version wasn't on large quantites or long lead times or until exhausted. They had about 150 A versions left.
I'm using the A version.
Brian
"Farnell have 4 suffix versions: NULL, A, B and BF.
NULL 45ms activation, no fault output
A 45ms activation, fault output
B 6ms activation, no fault output
BF 6ms activation, fault output
BF seems the best, as long as the LNB inrush current doesn't cause it to keep tripping and preventing a startup. I seem to remember that the Octagon OTLSO causes my Pace MSS508 to flash its SHORTED screen briefly, but if that's what was used for the MT MK2 add-on board, it must be OK".
Farnell is on a go-slow at the moment, but I checked earlier and only the B version wasn't on large quantites or long lead times or until exhausted. They had about 150 A versions left.
I'm using the A version.
Brian
Re: RT5047 U3 and U4
I think Dave GKQ must have got there before me and set it to maximum order = 2 which should solve the problem.
There 35 orders waiting to be processed and shipped!! Not sure I've got enough jiffy bags - again....
Noel
There 35 orders waiting to be processed and shipped!! Not sure I've got enough jiffy bags - again....
Noel
Re: RT5047 U3 and U4
Brian,
You are no doubt aware that standard metal filament fuses are very very slow in acting - in the order of many seconds if the overload is slight, and I am not sure about the time taken to vapourise (I am not American) the wire if the overload is many times the rating.
Anyhow, I feel that even the longer delay would be sufficient, especially if you consider you are protecting an inductor in the NIM from what I have read, and that, in effect, is a metal wire fuse which should take a long time (relatively) to fuse.
Who knows, I maybe wrong....
20mm Fast-Acting Ceramic Cartridge 1A to 4A
Rating 150% Rating 210% Rating 275% Rating 400% Rating 1000%
60min max 30min max 10ms-2Sec. 3ms-300ms 0-20ms
Mike
You are no doubt aware that standard metal filament fuses are very very slow in acting - in the order of many seconds if the overload is slight, and I am not sure about the time taken to vapourise (I am not American) the wire if the overload is many times the rating.
Anyhow, I feel that even the longer delay would be sufficient, especially if you consider you are protecting an inductor in the NIM from what I have read, and that, in effect, is a metal wire fuse which should take a long time (relatively) to fuse.
Who knows, I maybe wrong....
20mm Fast-Acting Ceramic Cartridge 1A to 4A
Rating 150% Rating 210% Rating 275% Rating 400% Rating 1000%
60min max 30min max 10ms-2Sec. 3ms-300ms 0-20ms
Mike
Re: RT5047 U3 and U4
I just tried shorting out the F socket 10 times with the 45ms A version and the NIM survived. The inductor in the NIM is very tiny, so I don't think it would take much to blow it.
Brian
Brian
Re: RT5047 U3 and U4
Brian,
That's very brave of you, considering the cost of a NIM.
The RT5047 can manage 550mA output current, maximum, typically it says.
An LNB uses under 250 mA I would say, worst case. Some internet searches say over 300 mA for C Band.
So the Serit inductor should be OK with 250 mA.
So worst case that is a 2:1 overload. So based on my very simple fuse model the NIM would blow in 30 minutes max!
I suspect the NIMs go when the RT5047 is NOT used and a full 12V/18V comes from a high current PSU (as I do).
I maybe wrong.
Mike
That's very brave of you, considering the cost of a NIM.
The RT5047 can manage 550mA output current, maximum, typically it says.
An LNB uses under 250 mA I would say, worst case. Some internet searches say over 300 mA for C Band.
So the Serit inductor should be OK with 250 mA.
So worst case that is a 2:1 overload. So based on my very simple fuse model the NIM would blow in 30 minutes max!
I suspect the NIMs go when the RT5047 is NOT used and a full 12V/18V comes from a high current PSU (as I do).
I maybe wrong.
Mike
Last edited by G0LJF on Sat Mar 27, 2021 12:18 pm, edited 1 time in total.
Re: RT5047 U3 and U4
It was drawing sparks, so the instantaneous current must have been high. I thought that with the longer 45ms activation time, it might cause a blip on the power supplies, but it carried on working.
It's fairly easy to restore the F socket power. Take the bottom cover off the NIM and the 40 way connector pins are visible. The appropriate pin can be wired to the F socket through a suitable choke. It might even improve the performance at 144 and 433MHz with a better choking arrangement, but I haven't tried.
viewtopic.php?f=105&t=5942&start=10
https://wiki.batc.org.uk/Serit_LNB_DC_supply
A lot of NIMs have a 500mA rating for driving DiSEqC motors. When I designed the PCB for the MiniTiouner BATC MK1 using the Sharp and Eardatek NIMs, I used a 200mA resettable fuse and I couldn't blow inductor in those. The inductor was probably rated for 500mA and more rugged. We used a higher value fuse for the MK1A and MK2 versions, but I didn't repeat the test.
Brian
It's fairly easy to restore the F socket power. Take the bottom cover off the NIM and the 40 way connector pins are visible. The appropriate pin can be wired to the F socket through a suitable choke. It might even improve the performance at 144 and 433MHz with a better choking arrangement, but I haven't tried.
viewtopic.php?f=105&t=5942&start=10
https://wiki.batc.org.uk/Serit_LNB_DC_supply
A lot of NIMs have a 500mA rating for driving DiSEqC motors. When I designed the PCB for the MiniTiouner BATC MK1 using the Sharp and Eardatek NIMs, I used a 200mA resettable fuse and I couldn't blow inductor in those. The inductor was probably rated for 500mA and more rugged. We used a higher value fuse for the MK1A and MK2 versions, but I didn't repeat the test.
Brian
Re: RT5047 U3 and U4
Hi All,
I have ordered the relevant parts from Farnell .
I went for the A RT5047. 45 ms of 'protection' delay.
I also selected a different Schottky diode from Farnell as the SS14 is not available in SOD123-FL.
I also note that the 10uH 2.5 A inductor was instantly on back order for some reason.
Here is a modified BOM. Please note there are two Schottky diodes.
73, Mike
I have ordered the relevant parts from Farnell .
I went for the A RT5047. 45 ms of 'protection' delay.
I also selected a different Schottky diode from Farnell as the SS14 is not available in SOD123-FL.
I also note that the 10uH 2.5 A inductor was instantly on back order for some reason.
Here is a modified BOM. Please note there are two Schottky diodes.
RT_Module_Farnell.xlsx- RT5047A Farnell BOM
- (961.13 KiB) Downloaded 417 times