Ben Nelson's Electro-Metro Build thread

[dremd]

Originally Posted by celblazer

re: I will rig that up to a momentary on switch for right now. It only takes about 5 seconds to pull -15 on the vac gauge

You can get a vacuum switch that is adjustable so you can set the pump to run automatically when needed(got to be safer then a manual switch. They aren't expensive. I'll see if I can dig up a link.

For example.
Link

Be careful that switch only adjust to 6" of Hg; which may or may not be sufficient for the brakes.

If anyone runs across a switch that can be adjusted much higher (for cheap) I need one also :-)

[celblazer]

Originally Posted by dremd

Be careful that switch only adjust to 6" of Hg; which may or may not be sufficient for the brakes.

If anyone runs across a switch that can be adjusted much higher (for cheap) I need one also :-)

K here you go: Linky

This looks interesting in the notes: Dual Pressure Switch: The DPDT (two switches) will both change state at approximately the same setpoint. On DPDT units, one switch may be set to lead or lag the other (see Custom Switches on next page).

OR U could use 2 switches, 1 for a low turn on and 1 for a high turn off. This way the pump will keep the pressure in the range you know is safe and not run every time you hit the brakes.

[dremd]

Re:
Awesomeness That's what bot Ben (IMHO) and I need!

[bennelson]

OOOOH! I like the idea of two switches for high and low set points!

[dremd]

Most Any pressure switch should have a low cut in and high cut off; it is called the anticipator.

[bennelson]

Well, I just got done with something on the car that really isn't a big deal, but still feels like a little bit of a milestone.

I installed a power inlet where the gas cap used to go.

Using materials I already had - Romex household wiring, some flexible conduit, and bits of scrap metal, I was able to make the car look like a "real" EV.



I fished the Romex through the conduit by pulling it through with some rope. I put the one end through the drain plug in the bottom of the spare tire well in the car. It's a hole that's already there, all I had to do was pull out a rubber plug. No drilling!

I pulled the other end of the conduit wiring up to where the gas cap was.

I bought the power inlet plug at the local marine store. I believe it is the EXACT same plug as is used on the ZENN.

However, the plug was just a little smaller than the hole I had for the original gas filler tube.

I cut the lid of a coffee can to test fit what I needed for some sort of a "hole reducer".



Once I had the plastic the right size and shape, I used it as a template to cut a piece of scrap galvanized sheet metal to the same size. The sheet metal went behind the hole and was attached with 3 sheet metal screws through the holes that originally held on the gas filler tube.

I also installed the 3 small black screws through the rim of the power inlet. They help snug it up a little more, plus, they look right in there.



On the back of the power plug, there are three holes you just slide the stripped black, white, and ground 120AC wires into and tighten down a screw for each. Then a rubber boot slides up and over the back of it.

I made sure the conduit was slid up nice and tight to the rubber boot, and wrapped a little electric tape around it just to be safe.

Looky here - an actual "official" charging setup!




PS: There is also a black and a white wire that come off the back of the charger. This is an AC output. I think it is designed to run an AC solenoid that will disconnect power to the motor controller when the charger is plugged in. That way, you can't drive the car off while plugged in!

I was thinking that maybe I could use that power out to supply AC to the 1.5 amp trickle charger I have up front which runs the accessory battery. I don't know how many amps can go through that extra output on the charger. I don't think a lot, but probably enough to run a very small charger?

[Daox]

That looks perfect (and very cool) from here Ben.

[bennelson]

Originally Posted by Daox

That looks perfect

Only because it didn't involve any welding!!!


I also rigged up a contactor in the trunk. A contactor is a very heavy duty remotely powered switch. This is sort of a master cut-off for the main power system.

The contactor uses 36V to run through the coil to make the main power connection. To do that, I ran wires from either end of three of the batteries.

I then ran those wires to a relay. That way, I can use 12V to activate the 36V to the contactor to connect it and run 72V through the main heavy power cables to the motor and controller.

But how do I run that relay? I wanted something nice and simple without wiring up another switch. Since there is no radio in the car right now, whatever went to it is free to use. I tried the switched power to the radio, but it didn't work. Must be a bad kink in that wire or something. The illumination power to the radio worked fine though.

I rigged the relay power up to that. Now, when I turn the lights on, it turns on the main contactor. Easy on/off switch.

I am sure I will wire it up differently later, but this is fine for now. At least now I have a panic button!

Main contactor (screwed down to plywood)


Shunt for 200 amp Ammeter (not yet permanently mounted)


Relay (foreground, blurry) which turns contactor on and off and switch (background, in focus) which turns on 72V power to the DC motor controller.




Seriously considering going for a drive in this car to pick up a pizza. No need to build a custom pizza rack in this EV!

[bennelson]

Yep, this is what I have spent all this time and work and money for.

To be able to do this:




Plenty of pizza room! No special rack design needed!



Now I just need the solar pizza oven.

Hmm - or maybe set the pizza on the controller or charger?

[MetroMPG]

I like the 300 mpg reflection in the window.