5v and 3.3v from Classic pcb

[dgd]

Looking at the top pcb of the Classic 150 I noticed near centre, there are three pads (or vacant through plated holes) marked bottom to top 0v, 3.3v and 5v. There is also a print for a diode, zener perhaps, between the 0v and 3.3v but no diode is present.
Are these voltages available at these points and if so what sort of current draw would be available? at 5v and 3.3v. If I wanted 3.3v would a 3.3v zener diode be needed in that empty location?
I would like to locate a small cpu inside the Classic wiring compartment and having power available from the Classic would make life so easy 

Also, is the battery temperature connector actually just an rs232 port? - seems the hardware connector being the an RJ11 same as other 3 serial ports and the connector cable to the temp sensor with six cores is pointing that way.
If it is then can it be accessed for other data? like the normal serial ports.
If not then could this be tacked on the 'to do' list for Clssic updates along with a 3 terminal mini screw down type cable connector to access those three voltages points as I notice the holes are apart the right amount to fit many common connector types 

dgd

[binkino]

first tought would be to follow the traces on the pcb and meassure whats h9ooked up the lines, checking datasheet how much it can support and what components are hooked up the lines, how much they draw ... ;-)

But from my view, I wouldn't do it. Build up the needed pwr source with a few components and get the source for it from the battery connector
A small discrete thing ... enough room in the case of the classic

[dgd]

It's near impossible to trace follow as its a multi layer pcb. Also getting from 48v battery V down to 5v or 3.3v is not trivial.
Those cigar lighter USB adapters are good for 12 and 24 batteries but I can't find anything for 48v even in the Chinese eBay offerings. There are others available but nothing at the $5 price range.

Anyway those three pads on the pcb look like they were originally planned for a connector socket for power supply to additional circuits or boards.
I must get the Fluke into action and at least confirm the voltages
I also notice two 9 way jtag connector places, again vacant rows of thru plated holes with the bottom hole in each set marked 0v and the topmost hole marked 3.3v, these are at right lower edge of pcb

dgd

[binkino]

A small step-down-converter would be posible, also adjustable ones
48V is not so easy, right. We have <60 Volts max (while charging)

Just found only step-down converter with 40 Volts input
but you could contact a chinese, if they can get a 60v input one


*idea* hey but wait. We have a 12 Volt line for the relais / AUXes ...


I have a 2nd system next to my main system (also 48v) but it is on 24 volts and so it was easy here for me to get a stable 12v for the router and all these things ...



Let's wait for the experts who have made the classic

[boB]

DGD, those pads are just for testing...  I suppose you ~could~ tack on a small micro to power from it BUT I would not really advocate this in general.
One of the reasons is that if something goes wrong, then the external micro could back-feed into the Classic circuitry and blow things up really good
That would void the warranty and we cannot support these kinds of applications.

BTW, here is a block diagram of the Classic with some I/O information.  I made this for folks that interface with the Classic but might need a bit more information on input and output loading and isolation, etc.

http://bob.midniteftp.com/Classic-Block-Diagram-5.pdf

Also, as you can see in this PDF, the battery temp-comp jack is an A/D input with a 3.3V pullup resistor.  The temperature sensor is
just a 10K (@ 25C) thermistor.

boB

[Vic]

Hi dgd,  David,  great questions/thoughts,  as usual.

THANKS boB,  for that Block of the Classics.   Very helpful.  73,   Vic

[dgd]

Thanks boB for the info.

I suppose its not for the faint-hearted but I couldn't resist seeing what those pads were doing and being well aware that my #879 is probably warranty expired anyway, I carefully wielded the needle point iron and got some wires into the 0v and 5v pads.
I'm also pretty confident that the likelihood of a small Arduino Nano doing a catastophic failure where the power lines short or reverse, is pretty minimal.
So its all together and appears to be working well, current draw to the Nano is a few milliamps but the max232 board needs about 8ma. The Classic works normally 

There is some satisfaction in appropriating the 5v supply from the Classic, after all its a power converter dealing with Kw of power so a couple of milliwatts pinched from its circuit board seems insignificant.

Maybe in the next pcb revision we could get a USB connector that can supply 5volts at an amp or so that an ipad or cheap android device could be left permanently connected to  the Classic
Or maybe that 3 terminal connector with reverse polarity protection 

dgd

[dgd]

Thats an interesting block diagram boB.
Made me think again about that USB serial port 
Does it behave like the rs232 serial ports and will it respond to modbus requests for register data? I suppose I could try it and see but I do remember somewhere in past discussion that some data could be extracted from that USB port. Is there any updated info available?

dgd

[dgd]

Vic,
I'm just having some fun adding useful bits to a Classic. 
I loaned a C150 to replace a C250 that was flattened when a logging truck missed a sharp turn and  took out a small power shed by rolling several tons of forestry over it. 
Although the Classic's alloy case was well broken, mngp and case top wrecked  the main pcb seems to have survived with just a somewhat flattened ethernet connector and bts socket.
I risked power it up with a 12v battery and a spare MNGP and it worked !!!
Thats given me the opportunity to study the pcb more closely than usual and see these power connectors

dgd

[Vic]

Vic,
I'm just having some fun adding useful bits to a Classic. 
I loaned a C150 to replace a C250 that was flattened when a logging truck missed a sharp turn and  took out a small power shed by rolling several tons of forestry over it. 
Although the Classic's alloy case was well broken, mngp and case top wrecked  the main pcb seems to have survived with just a somewhat flattened ethernet connector and bts socket.
I risked power it up with a 12v battery and a spare MNGP and it worked !!!
Thats given me the opportunity to study the pcb more closely than usual and see these power connectors
dgd

Hi David,

Too bad about that Classic 250,  but sounds like the Classics are fairly tough.  I had really wanted to look at more of the guts of a Classic,  but did not want to tear into one.   I will leave well enough alone,  and let them work.

You,  and some others are doing interesting work on adding functions to your power systems.  I particularly liked that you are using a/some WBjr/s with your own processor to gather data from Shunts that are not in the battery negative lead of the main system.   Very cool,  and it was very nice of boB to share the protocol for accessing the WB.

Have Fun,  and hope that you folks have a great Winter.    Thanks,   Vic

[boB]

Thanks boB for the info.

I suppose its not for the faint-hearted but I couldn't resist seeing what those pads were doing and being well aware that my #879 is probably warranty expired anyway, I carefully wielded the needle point iron and got some wires into the 0v and 5v pads.
I'm also pretty confident that the likelihood of a small Arduino Nano doing a catastophic failure where the power lines short or reverse, is pretty minimal.
So its all together and appears to be working well, current draw to the Nano is a few milliamps but the max232 board needs about 8ma. The Classic works normally 

There is some satisfaction in appropriating the 5v supply from the Classic, after all its a power converter dealing with Kw of power so a couple of milliwatts pinched from its circuit board seems insignificant.

Maybe in the next pcb revision we could get a USB connector that can supply 5volts at an amp or so that an ipad or cheap android device could be left permanently connected to  the Classic
Or maybe that 3 terminal connector with reverse polarity protection 

dgd

Well, we have this three (3) letter word in the US...  CYA....  No, it does not mean good-bye.  Means cover your @^#.
I'm glad it worked for you !   (I can't believe this forum software changed those last 3 letters !)

As for the USB connection, I've thought it would be nice for it to be modbus endowed but no, it isn't.  I is for various things like
updating and spitting out some useful data, etc.  There is a menu you know in the MNGP  MISC COMM menu that can chane
its mode, other than code update which is always available for the first few seconds after powering up the Classic.
It's not real useful except I think, for spitting out the raw volts and amps at around twice per second or so....  If captured,
can make pretty and somewhat useful graphs if captured and placed into excel by way of  CSV logging file from your
terminal program.

boB