grezzy
10 µW
Hi does anyone have schematic for APT72400 controller? I need to id this component ie type of component and value, i think it a ceramic cap but one has exploded on other end of board. Anyone help ? Thanks 
APT 72400 SCHEMATIC COMPONENT ID
- Thread starter grezzy
- Start date
Unfortunately, unless you reverse engineer it and draw it up, there aren't any schematics for pretty much any controller***, other than the few open-source projects where that would be available on the project page. 
If it's a ceramic cap (and not a resistor) then to make one explode would require extremes that would have destroyed other parts in there, too, including the electrolytics on the same bus, FETs, etc.
What other parts were damaged, and what happened to the system to cause the damage?
If you have a component tester with capacitance testing, you can remove it from teh board and find out it's capacitance. The voltage you can guess from the max system voltage--whatever's rated above that should work, as far above it as practical.
***there are partial schematics of some ancient "infineon" based controllers scattered around the forum from a decade and more ago, and possibly partial ones of some areas of some other controllers more recently, but I don't recall any APT.
If it's a ceramic cap (and not a resistor) then to make one explode would require extremes that would have destroyed other parts in there, too, including the electrolytics on the same bus, FETs, etc.
What other parts were damaged, and what happened to the system to cause the damage?
If you have a component tester with capacitance testing, you can remove it from teh board and find out it's capacitance. The voltage you can guess from the max system voltage--whatever's rated above that should work, as far above it as practical.
***there are partial schematics of some ancient "infineon" based controllers scattered around the forum from a decade and more ago, and possibly partial ones of some areas of some other controllers more recently, but I don't recall any APT.
grezzy
10 µW
Hi thanks for replying, this controller has suffered water ingress at some stage as you will see in attached photo pic1 is immediately after the case was opened and pic 2 is the site of missing components, i have a new controller on its way but i would be really happy if this could be save this controller, i dont like to bin things if there any possible way to repair. Thanks and let me know your thoughts
Attachments
If there was water ingress and it was powered up while that was in there, it's fairly likely there is damage to low-voltage parts (like MCU, gate drivers, etc).
If missing, that cap wouldn't stop it from operating, so if it is not working at all then it's not the cap causing that. Assuming it is a cap, and It's on the power bus it's just another filter for other frequencies than the big can style caps also on that bus.
If the part that's failed is not a cap across the power bus, but instead is a shunt resistor between the battery negative and the FET negative, then it may have exploded (vaporized) from overrcurrent due to shorted FETs (or FETs all being turned on at once) causing shoot-thru, connecting the main B+ to the main B- thru the FETs and the shunt.
I'd recommend tracing out the main power paths to see if that's the case, and then testing the FETs for resistance (there are various posts on that here, and also on the ebikes.ca site in the learn-troubleshooting section).
If missing, that cap wouldn't stop it from operating, so if it is not working at all then it's not the cap causing that. Assuming it is a cap, and It's on the power bus it's just another filter for other frequencies than the big can style caps also on that bus.
If the part that's failed is not a cap across the power bus, but instead is a shunt resistor between the battery negative and the FET negative, then it may have exploded (vaporized) from overrcurrent due to shorted FETs (or FETs all being turned on at once) causing shoot-thru, connecting the main B+ to the main B- thru the FETs and the shunt.
I'd recommend tracing out the main power paths to see if that's the case, and then testing the FETs for resistance (there are various posts on that here, and also on the ebikes.ca site in the learn-troubleshooting section).
grezzy
10 µW
Thanks very much for the info Amberwolf i really appreciate your advice, the controller does power up which is one of the reasons i thought i would give this mission a go, after powering up everything looks normal untill throttle is turned nothing happens, no motor movement, i will look at the trouble shooting section on the website link you sent. Ill update when i get more info, thanks again Amberwolf have a great day
Even if the shunt is missing, so no power to FETs, the controlelr brain will still power up, but the FETs (motor phases) will get no power.
grezzy
10 µW
If you mean the part that's still there, as pictured in the first post, then yes, that is probably within tolerances of the part and the reading of the meter itself, for a 4.7uf cap.
But you still don't know what the other part was; if it was a cap, or a shunt, etc...have you traced out the circuit leading to and going away from the damaged part?
The problem you are having with it wouldn't be fixed by having one more tiny cap added in parallel to all those others. But replacing a missing shunt providing a battery negative connection to the FETs...that would. (well, after whatever problem it has that causes a high enough current to vaporize the part is fixed).
But you still don't know what the other part was; if it was a cap, or a shunt, etc...have you traced out the circuit leading to and going away from the damaged part?
The problem you are having with it wouldn't be fixed by having one more tiny cap added in parallel to all those others. But replacing a missing shunt providing a battery negative connection to the FETs...that would. (well, after whatever problem it has that causes a high enough current to vaporize the part is fixed).
grezzy
10 µW
Yes sorry, i did mean the good cap in picture that was still on board, so i did confirm that the missin component was exactly same as that good one in my photo by seeing a picture of an apt72400 in bits, so we have a 4.7uf ceramic cap and, by its physical cage size, i should be able to work out its voltage rating although i my head its going to be 100v but ill confirm that later lol. Next step is checking circuits going to and from missing cap site, and i need to check mosfets not sure if they can be checked in situ or if they need desoldering but ill find out. So thanks to your help so far amberwolf, things are looking ok so far and i really do appreciate your help.
To be continued ....
To be continued ....
If it's on the same bus as the big electrolytics, parallel with them, then it should be rated at least as high as they are.
grezzy
10 µW
Pretty much came to same conclusion Amberwolf, the exact type of cap is my issue there must be half dozen different types, would this cap be some sort of circuit protection ?
I have the physical/cage size 5750 (2220 imp)
the value 4.7uf
voltage 100v
TBC......
I have the physical/cage size 5750 (2220 imp)
the value 4.7uf
voltage 100v
TBC......
I'll just quote from earlier in the thread, since I don't have any other info on it:
But also:
There's no point in replacing the cap until you have it working. Replacing the cap will not make it work if it's a bus cap in parallel with other bus caps.
(you can look thru the various controller design threads to see why different caps are used).
But also:
There's no point in replacing the cap until you have it working. Replacing the cap will not make it work if it's a bus cap in parallel with other bus caps.
