Enginer PHEV automatic over/under voltage protection

The arduino will definitely be on while charging. In the original setup (with no dc to dc converter disconnect), I had planned on powering the arduino with a wall wart type power supply. When you plug in your extension cord to the car it will power up the wall wart which will power the arduino. Once the arduino boots, it will close the relay and allow 110V power to the charger. However, when the car is on, the arduino will be powered off the car's 12V.

The thought had occurred to me. Also, Eric posted the same concern. The VOX circuit does have an adjustment potentiometer on it to adjust sensitivity. This will need to be adjusted for it to work properly and should filter out any quieter noise the VOX may pickup. However, I have also programmed logic into the arduino to identify beeps versus normal noise. A few clunks here or there will just be ignored by the arduino. I'm confident that (perhaps with a little tweaking) it will work not disconnect the pack unless an actual alarm is going off.

You could crack open the balancers and tap directly into the alarm signal that goes to the speakers, but I'm trying to design this so you don't have to cut any wires or take anything apart. It'll just be a few connectors that go between other things in the kit.

Haha, not at all. Questions just make me mull things over and rethink things to verify them. Nothing wrong with that at all. It eventually leads to a better design. Case in point, what happens if you have the car on and its charging? The arduino will have 12V from two sources. I'll have to see if this will be a problem.

 

I don't quite understand what you are talking about.

As it is now, the 110V relay is normally open. The arduino must power up first in order to close the 110V relay and allow power to the charger.

But, I think you knew that.

 

Yeah, my electronically minded friend warned me not to disconnect the pack from the charger, but rather the 110V from the charger. He knows a lot more than I do about that stuff, so I just listened. He also suggested using the normal power switch signal to power down the dc to dc converter. Its always better to work with low voltage/amperage stuff anyways.

 

I tested out the VOX circuit tonight. It works well, but will need a little tweaking. I shot some low quality video of how it works. Comments and questions are welcome.

BTW, one of the members on Ecomodder thought it was funny how I was basically making a clapper for my Prius.

 

Has he provided any additional information on this? Cutoff voltages? Its great that the NEW cells have this, but what about everyone else? How new is new? A lot of us recently purchased our kits too. Could you get some of this info for us?

 

Can anyone verify that the 12V 'ready wire' is actually the activation wire for the OEM high voltage pack's relays? I looked in my pictures last night and I couldn't tell. I'm pretty sure it is. There really isn't a reason to send 12V since most logic signals are 5V.

 

The reason I'd like to know is because I am tapping into the ready wire to get power for the arduino and relay. Its possible, although unlikely, that the ECU's ready wire (mainly the chip in the ECU) may not be capable of powering up these devices. If that is the case, I might fry the chip in the HV ECU, not good! However, if the ready wire is actually being used to power the contactors, I know there is plenty of overhead for me to steal a little power for the arduino and relay.

I know how I can test it, I just was hoping someone already knew. I don't really want to take apart the back end of my car AGAIN.

 

This weekend was an EV build day for our local EV club. I went and shared what I was doing with the Prius and got some help with modifying the VOX circuit. We were able to remove the on delay that the circuit had built into it. However, we could not get the VOX circuit to trigger well off of the balancer alarm. It was much more sensitive to us just talking in the room. We figured that the circuit was more sensitive to lower frequencies than the higher frequency of the beeper. At this point, the option was to try and find a high pass filter that only allows higher frequencies through, or to dump the VOX all together. In the end, we decided to dump the VOX.

So, as a few here have suggested, we open up a balancer and looked at the signal going to the beeper. It should be usable, but I'm going to have to reprogram the arduino for this new situation. The beeper acts a bit oddly. Nothing that can't be programmed around though.