I started out with a simple goal to experiment with Toyota Prius gearbox and inverter and get
it to work as an electric drivetrain using open inverter board things took a thrilling turn when
I came across a cheap Tesla motor on eBay I could not resist the opportunity to take things up a
notch I decided to risk it so it does look quite worrisome to go for this one however the offer is
too good and I'm just gonna say I'm authorizing the payment okay your order is in right well I
feel quite relieved but at the same time it just feels so scary I could be wasting 700 pounds on
this anyway we need to wait and see what's going to happen of course after I placed an eBay order
for the Tesla Motor I needed to get a version of the open inverter board that will work with the
Tesla small Drive Unit I had downloaded the design files from Damien GitHub and went to glcpcb to get
the board ordered the design files were uploaded but had come across a few component shortages
I was able to find pwm driver easily from Mauser but as a power switch I see goes I had to resort
to going on AliExpress and ordering few of them from there and the good news I already received
an email notifying me that the shipment is coming the bad news I have to pay custom clearance nv80
despite the fact that it's a second hand item and would you believe it it did turn up and here we go
this is the motor behind me the package with the mortar arrived a week earlier but I did not have
an opportunity to start working on it but once I had a little bit of time I started unpacking the
package with excitement and worry mixed together I was quite pleased with my initial observations
as there were no sign of any damaged Parts the only downside was clearly visible signs of the
aluminum corrosion on some surfaces of the motor and the great extra bonus the high voltage cable
was completely intact my goal for this task is to remove Tesla inverter cover but to gain access to
the cover I first will need to remove the cooling pipes and the black foam cover that isolates the
inverter top I also decided to remove high voltage cables to make my life easier later on this little
orange cup is covering the three-phase connection from the motor to the inverter
until those three connections undone it would be impossible to separate inverter from the motor
and of course Tesla don't want you to go there since you peel off the label you are presented
with lots of warranty void messages on the label itself I removed the screws securing the cables
for the phase 1 2 and 3 to the inverter after all this unbolting inverter was very straightforward
exercise the only sticky part was unplugging a temperature sensor connector and encoder connector
with the inverter removed I couldn't help but admire incredible level of Technology Tesla had
even in 2013 when this car was built now I can focus on removing the top board from here I need
to remove the whole bottom plate and the board together because the bottom plate has current
sensors embedded in a plate and there soldered straight to the board I found that the best way to
get rid of protective Locker would be to heat it up with the soldering iron and actually scrape it
off while moving the soldering iron across those three contacts having removed the locker layer
I started to use lots of flux and sacking device to suck out all the solder from those connectors
well looks like I messed up really badly guys unfortunately I was trying to unsolder these
senses the current senses and each of them has four pins and I broke one pin off each sensor I
had a good look at the sensor and I could not see any remnants of the leg remaining on body
of the sensor but I decided to remove it anyway unfortunately the pin was broken right at the
root of the casing well what a day where do we go from here no idea in despair I went searching on
the open inverter forum and DIY electric car forum for replacement sensors I also posted a question
on open inverter Forum but so far no one came back with any advice and at this moment help came
from completely unexpected source if only someone had done all this work years ago and posted it on
video and Forum the sdu current sensors I'm Alexis mlx91209ca exactly the same as model 3 drive units
usually in stock at Mauser I had a quick look on the mouse website and yes indeed they were
available the only one little niggle was that the right model was not there but help came again from
fellow AV conversion into this I'm not sure if it helps but I searched for 7.3 millivolt per
millitor and found as Electronics seems to have them in stock and yes indeed they were available
and I got them now with renewed hope I started to work on finishing the open inverter board so it
is ready when the sensors will have arrived when I ordered the open inverter board for the Tesla
small Drive Unit A few components were missing those were pwm driver and if it is that drive the
pre-charge and Main contact factor I have started from pwm driver as the smallest component it was
fairly easy to solder at this stage I decided to actually test the board to ensure that both
Supply voltages are present as I did not want to do any more soldering and find out that part
of the board is not working I quickly hooked up 12 volt wires and connected to my power supply
so we are not consuming any current and power is zero so this means that our voltage is not
getting into our system so what I need to do is to measure 12 volts on the input and we are getting
1198 and we are getting only 0.6 volts on after the diet this means that this diet is maybe not
soldered incorrectly so let's have a look and see whether we got the right polarity for this diet
I found that my board was assembled incorrectly and cathode the negative electrode was connected
to the 12 volt Supply and positive anode was connected to the capacitor obviously I needed
to reverse the polarity of the this die I decided to check the second shotkey diet in the schematic
that was connected to the output of the voltage regulator and to my disappointment found the
polarity of that one was also wrong I unsoldered both diets clean the pads using solderwick and
now soldered them back in this time using right polarity right let's give it a try our supplies
on enabling the power and it's working LED is on fantastic at this point I noticed that my 3.3
volt Supply was drifting while 5 volt Supply was very stable right I think I found another mistake
the 3.3 volts is dropping is because this marked side of the tantalum capacitor should be plus and
it should be connected to pin 2 of The Regulator here it's 3.3 volt wow I'm beginning to think that
this Tesla build is cursed but in this case I'm enjoying solving these little problems and moving
on to the next one I removed the capacitor using the same method as I used for the diet and sold it
back in in reverse polarity connection Now power supply Zone and now 3 volts 3.28 and it seems
quite stable another problem solved I decided to program Open Tesla inverting board before
I start soldering any more components as usual I use st-link programmer to do the programming bit
first I need to connect hastilink programmer and load the bootloader program and verify after this
I could program the signed firmware and program and verify again yes this looks good no surprises
this time for me once I programmed the board and I could see that it was working I could finish
off by adding missing components soldering fats is a bit more challenging as they have rather
large heatsinks I had to cover the part and ipt backside with the flux and heat the part for much
longer to ensure that solder properly had flown into the pad now I have external connector on the
board I need a receptacle part so I can expose some connections for testing this means that I
have to assemble Molex connector and crimp some wires well let's get crimping excellent guys our
board is progressing nicely and it's almost ready for testing I already have a connector
and testing harness build up now I want to do a simple startup test just to start an
inverter power on ignition on press start button and see if the web interface shows that inverter
is started okay first I need to plug in the connector here oops so we rearranged our
power okay now the crunch time power supply is on and apply the power and the switch on
and it's working as for the rest of this test I had to reconnect to the ESP module to make
sure that I have a connection to my vmos D1 mini and then start inverter in the manual mode and
invert the started excellent It's Working the task is to put the Tesla open inverter board
which will go in this position over here I took the approach where I fitted sensors into the PCB
first without actually soldering them in and then I could load the PCB with the sensors
into the base plate mounting position and fit the fixing screws okay now we can assemble the
board two of the high voltage cables will go through these I finished the Assembly
of the board and I just needed to fit in the bracket directing the three-phase high voltage
cable that's connected to the motor terminals installing inverter back was very simple Affair
to finish off all I needed to do is to attach the three screws that holding the phases that go from
the inverter into the motor I've decided just to carry on with the testing by using pipe inserts
so what I found 10 millimeter pipe push fits can be actually fitted in this cable quite easily and
they actually really make perfect connection okay I'm using pipe inserts great decision but
how do we gonna attach the cable I think there is not enough space for crimping so I've decided
of course to try soldering I quickly sold it in the connector cable for the high voltage plus and
minus and isolated the part of the cable that was sticking out from the pipe I have my setup
here which some people may call Heath Robinson but for the first test I think it's going to be
okay so these connectors really work well so they plug in into the high voltage cable and fit very
nicely so the rest of setup is here so we have pre-charge contactor main contactor pre-charge
resistor and our famous Prius throttle pedal this red and black wires would be out 12 volt
Supply and this is the ignition switch and this is our start button and this little switch there
it's our Direction switch well it's all good talking about 12 volts but you may ask where
is the high voltage how do we power the motor for this test I'm using a Contraption of four power
supplies connected in series and for the first test I decided to connect in the bolt to work
as a some sort of a protection limiting current device as well as an indicator the amount of glow
will increase with proportion of current drawn by the inverter right so now we're going to try the
first run I am a little bit nervous I have to say but hopefully our bulb will work as an indicator
of how things are and I expect it to light up at the first moment during the pre-charge cycle so
once precharge cycle is complete I expect the bulb to turn off you can see that the bolt is flushed
yeah pre-charge is closed and Main contact is open after I increase the current limit for my
12 volts power supply if I pressed on the pedal the bulb started to Glow this was an indication
that we're actually drawing more current but the motor was not rotating but once the pedal
was released and the current stopped flowing so I've decided to run another experiment with the
bulb removed okay I now removed the bulb and the factory we have this connection instead of
the bulb and it goes straight into the main contactor high voltage power supply is on
now I'm switching the low voltage power supply so now 12 volts is enabled
and we have a rotation unbelievable so this is our pedal
I press the pedal and you hopefully can see that motor is rotating put the motor in reverse
and it's going in reverse
okay now it's stopped and I'm gonna go forward
and it's going forward
it feels rather smooth
fantastic wow the motor is working what a relief when I damage the current sensors I did not think
I will ever get it to spin again I hope you enjoyed this episode please give it thumbs up
if you did please like And subscribe if you want to follow along and I will see you on the next one