keep alive in BLI Cattle car


gnguyincalifornia
 

Anybody know where to solder the leads for a Keep Alive / Current Keeper in the QSI BLI cattle car????
see attached photo.

Mike Stewart
Oakley, CA


kjlovesya
 

Hi Mike,

  Educated guess!  Verify with a meter. 

  The four black 'blocks' in the upper right are likely the four diode components making up a full wave bridge rectifier.  (look it up if you don't know what that is)

 It looks like the large light green area on the top left (near the screw) is the - side.   The smaller light green on the top right is likely the + side.

Best regards,
KJ


Bob Waldele
 

Mike

Have you checked with BLI Tech Support?

I’m not sure that this particular board was made by QSI for BLI – it may be BLI’s own specification by whomever was also producing their Paragon series boards.

Regards

Bob.Waldele

 

From: QSIndustries@groups.io <QSIndustries@groups.io> On Behalf Of gnguyincalifornia
Sent: Thursday, November 4, 2021 4:28 PM
To: QSIndustries@groups.io
Subject: [QSIndustries] keep alive in BLI Cattle car

 

Anybody know where to solder the leads for a Keep Alive / Current Keeper in the QSI BLI cattle car????
see attached photo.

Mike Stewart
Oakley, CA


gnguyincalifornia
 
Edited

Bob,

Yes, I checked with BLI first and they said it was QSI and they no longer support it nor have any wiring diagrams for it.
I used their actual model # 827 in my correspondence.

Mike Stewart


gnguyincalifornia
 

KJ
I'm new at this but I put a meter (in  DC mode) across the points shown in the photo and got 12 volts DC.  So I should solder the positive and negative wires from the keep alive to these two points.  Right ???

Thanks
Mike Stewart


Talmadge C 'TC' Carr
 

NO; Not there. You must get DC when in DCC mode.
DCC includes a signal called bi-polar DC which is why some say it is AC. That signal will destroy a capacitor. Unless it is also Bi-Polar as in a speaker. However, that will not work as a keep alive:(
You must get the positive and negative after the diodes. Look for the place it feeds the micro controller but before the voltage regulator.
TCC:}
Moderator

Talmadge C 'TC' Carr
Sn42 and Hn42 somewhere in the wilds of the Pacific Northwest
group_list@dapenguin.net

On 05November2021, at 22:15, gnguyincalifornia <gnrrguy@gmail.com> wrote:

KJ
I'm new at this but I put a meter (in DC mode) across the points shown in the photo and got 12 volts DC. So I should solder the positive and negative wires from the keep alive to these two points. Right ???

Thanks
Mike Stewart
--
Talmadge C 'TC' Carr
Sn42 and 35n42 somewhere in the wilds of the Pacific Northwest
group_list@dapenguin.net


kjlovesya
 

Hi Mike,

  Talmadge is correct in that the DC signal is after the rectifier diodes.   I'm pretty sure those are the points I pointed to.  However, there is another continuity test to determine if my suggestion is correct.   You can use a Ohm meter (DCC power OFF).   The Ohm meter has an internal battery so you don't want external power.

  With a Full Wave bridge rectifier, one half of each of the two diodes will share one rail of track and one half of the other two will share the other rail of track.

  You can put the ohm meter between one of the two pins of the connector marked "P1 Track"(the wired white connector) and find out which two diodes that rail shares.  The opposite side of each of those diodes will be either - or + .   Connect the Ohm meter lead to the opposite end of one of the diodes and note the Ohm meter reading.  Now reverse the two Ohm meter leads.  You should see a difference in the meter reading.   The diode only conducts in one direction. 

  Do the same for the other diode.  You will now definitely know at least one track input and common - or common +.

  Next, do the same operation with the other pin at "P1 Track", this time checking continuity between the other two diodes.  You should be able to see the shared common outputs (+ and -).

  Those shared points are where the DC lives.  That is where you can safely connect your keep alive (bearing in mind, as Talmadge mentioned,  polarity is crucial).  Connect the blue wire to + and the black with white striped wire to -.

  Do not hesitate to ask questions.  That is what we are here for.   :-)

Best regards,
KJ

  To determine


peteski7
 

This task would be easy if you could take better lit closeup photos of the top end of the board where the connector with 2 black wires is, along with the 2 large cylindrical components (electrolytic caps) are. Take photo of the front and back of the board.  Then we should have no problem identifying where to connect additional capacitance.

BTW, it is a QSI-made board.  I see "QSI" on the large IC (chip) on the bottom of the picture.

Peteski


gnguyincalifornia
 

Here are the closeups.  thanks for your help.

Mike  Stewart
Oakley, CA


peteski7
 

Hi Mike,
Looks like you did figure it out correctly.  Here is my take on the circuit (which agrees with your earlier speculation).




Just to verify, take a ohmmeter or continuity tested and check whether there is a continuity (zero ohms) between the pairs of red and pairs of blue points (as shown in the photo). Also check if the capacitor's leads might be connected to the blue and red points. They might not be.  If the diodes are connected as shown then I'm pretty sure the keep-alive circuit can be connected to either of the blue and red points (diodes).  Red is + and blue -.  You could also power up the circuit and measure the voltage between blue and red. Should be around 12V DC when powered from DCC track.

Peteski


gnguyincalifornia
 

Checked continuity and all was good.  soldered it up and it works great.  Cows keep mooing after I take it off the track.  Also, prevents sound hiccups when I go over dead frogs.

Thanks to KJ for identifying the two spots and Peteski for a way to verify before I smoke my decoder :)

Mike Stewart
Oakley, CA


peteski7
 

Ah, now you have a very long MOOOOOOOOOOOOOO!  Life is good!  :-)
Peteski