OpenEVSE - Open Source Charging Station

[garygid]

I recently received the XMEGA XPROTOLAB miniature oscilloscope
(2 analog 2mHz sample and 8 digital channels, plus voltmeter,
frequency counter, and wavefrm generator), and hope to use it
to view the Control Pilot signal later today.

I also have two of the ChronoDot RTC devices on order, to try out
goldserve RTC and Timer support in his version 1.6.2 firmware.
This RTC can be added easily, requiring only a 4-wire female to
female (1x4 headers) cable to insert it between the LCD display
and the OpenEVSE Plus control board.

 

[borland]

I'm planning on building a 32 amp Open EVSE, can these 30 amp assemblies be used or upgraded? I assume the rating is based on the cable's wire gauge and length and not the plug rating.

do not exceed the published rating of any components because an electrical fire is the last thing you want in your home.

Doesn't answer my question, but thanks for the reply. Good point. If you don't know what your doing, don't do it.

I guess I've figured out the problem with upgrading a 30 amp rated cord with 3x10 AWG cable to a higher rated capability. The problem is that there are no suppliers for SAE J1772 in 3x8 AWG gauge cable.

For J1772 without proximity, I could use a more common 8/4 SEOOW cable, but I believe the diameter and bulk would be the same as a J1772 in 3x6 AWG (no savings in cable diameter and bulk).

So for now, the only reasonable choice, is to buy the bulky Leviton 75A rated J1772 cable/plug assembly.

http://store.leviton.com/Electric-Vehicle-Charge-Connector-A2055-PEV/dp/B009UCEXYI" onclick="window.open(this.href);return false;

 

[garygid]

Chris,
Is there a schematic for the OpenEVSE Plus board?

I would like to determine what the non-ground pin of the 1x2 header
Coil Test Future is connected to.

If easy to do, I would like to re-purpose that to have the Control Pilot,
to easily connect the EV Simulator board.

 

[GlennD]

Just do as I do and connect the pilot to a terminal strip before it goes to the board. This way it is real easy to clip a simulator on. Much easier in my case than getting to the side mounted board.

 

[Don123]

So for now, the only reasonable choice, is to buy the bulky Leviton 75A rated J1772 cable/plug assembly.

Do you really *need* those last 2 amps?

Why not buy the 30 amp components, build a 30 amp EVSE and then adjust it to charge at a max 30 amps? You'll have 94% of what you want at a much lower cost and in a more compact package. Your recharge time will be 6% longer (or for a given time, 6% less charge) but will that really matter in your case?

The EVSE I built for my iMiEV is 20 amp capable, the charger in the car can draw a max of 14.5 amps @ 240V but I've always had my EVSE set up to charge at just 12 amps. Why? I've never needed it to charge any faster than that (actually, I use L1, 120V@12 amps 90% of the time) plus I just feel better not pushing anything to 100% of it's rated capability unless it's absolutely necessary

Don

 

[chris1howell]

Chris,
Is there a schematic for the OpenEVSE Plus board?

I would like to determine what the non-ground pin of the 1x2 header
Coil Test Future is connected to.

If easy to do, I would like to re-purpose that to have the Control Pilot,
to easily connect the EV Simulator board.

There sure is. Its in the downloads section of the OpenEVSE site.

The pin you are referring to is for gfci self test. It is a digital io pin connected to a 330 ohm current limiting resistor. You can not put.the pilot on that pin. The pilot is on a hardware PWM pin.

 

[GlennD]

The answer is not really. You have not yet put out schematic or at least a pinout of your current board. For me that is not a problem since I have figured out your current connections.

It is a problem for a careful worker that just follows examples blindly. You and I know what we are doing, but everyone is not that lucky.

 

[chris1howell]

The answer is not really. You have not yet put out schematic or at least a pinout of your current board. For me that is not a problem since I have figured out your current connections.

It is a problem for a careful worker that just follows examples blindly. You and I know what we are doing, but everyone is not that lucky.

You are right GLENN. Looks like the latest is missing. I will do a clean up tomorrow and depreciate the older files and add the new ones.

 

[garygid]

Thanks for the info, and for working on getting the
OpenEVSE Plus schematic up there. Would you also
put the schematic up as a PDF file so special software
is not needed to view or print it?
Thanks, Gary

 

[chris1howell]

Thanks for the info, and for working on getting the
OpenEVSE Plus schematic up there. Would you also
put the schematic up as a PDF file so special software
is not needed to view or print it?
Thanks, Gary

Just upload files for:
OpenEVSE plus v2 (shipping soon adds 2nda relay output)
OpenEVSE plus v1
RBG LCD backpack
RGB LCD backpack with Real time clock

 

[goldserve]

Chris, can you sell me a LCD backpack without RTC?

 

[chris1howell]

Chris, can you sell me a LCD backpack without RTC?

Did you recieve the one I sent you last week?



Yes, I am just about ready to start shipping both boards in 3 versions at the end of the week.

Board only
Kit (Board, RGB LCD, 4 pin cable, spacers and headers)
Built and tested (Board, RGB LCD, cable, spacers and headers)


RGB LCD
Board only/ Kit/ Built and Tested
$20 $30 $40

RGB LCD plus RTC
Board only/ Kit/ Built and tested
$30 $40 $50

 

[chris1howell]

I'm just starting to read about the OpenEVSE project. It sounds like a great little side project

But, is there any sort of surge suppression in the OpenEVSE design? I haven't spent a great deal of time poring over the schematics and design, but I don't see anything there.

Depends if you build it into your EVSE. The controller board has a TVS diode on the pilot line.

Many builders add two MOVs from Hot 1 to Ground and Hot 2 to Ground.

 

[goldserve]

Yes, I got the package you sent and it works great. Sign me up for one:

RGB LCD
$30 option.

Cheers!

 

[Volt3939]

I'm just starting to read about the OpenEVSE project. It sounds like a great little side project

But, is there any sort of surge suppression in the OpenEVSE design? I haven't spent a great deal of time poring over the schematics and design, but I don't see anything there.

Depends if you build it into your EVSE. The controller board has a TVS diode on the pilot line.

Many builders add two MOVs from Hot 1 to Ground and Hot 2 to Ground.

In robbing parts out of my old Volt 120V trickle charger I noticed it has (had) a 470V MOV across the pins marked Line1 and Line2. I have a bin with 150V MOV's that I was planning on using Line to GND as you describe, but since this part is now free, it will probably go in my OpenEVSE build, which is going into the Voltec case.

The Volt prototype I took apart last year had only one Line pin, the other was marked NEU. It still has 3 relays for GND, Neutral and Line, but the two dedicated PSU's for 5V and +/-12V have been swapped for a single universal supply that was quite happy to run on 240V. This is actually the EVSE that came with my car back in June '11, before the redesigned units were available.

Has anyone used a single button to set Max Current? I'd like to use the one on the Volt case to switch through 4 settings,say 6, 8 10 and 12A. It would be nice to use the 4 LED's as well to indicate the current setting, but I could replace them with an LCD...

 

[borland]

volt,

With the current design, most of the processor's I/O pins are utilized. Take a look at the schematic posted on the Open EVSE site.

You'd need to do an inventory of all the LEDs that you require and compare that with available LED, relay outputs, and unused I/O pins.

If not enough are available, you could provide additional LEDs via Open EVSE's I2C port using another processor or add a logic circuit to drive the LEDs that multiplexes two output into four.

Course all of this would require modified Open EVSE firmware to support your required button/LED/no-LCD functionality.

 

[garygid]

At the latest mini-workshop for building the OpenEVSE Plus
projects, we were trying to add a 1x2 female plug to the
wires from the Current Transformer.

Problem:
The insulation on these wires is too fat to fit into the 1x2 housing,
and it is very difficult to crimp a female pin onto these wires,
because of the too-fat insulation.

We tried:
Using a sharp exacto-type knife to carve down the last 1/4 inch
of the insulation, and that could have worked, if somebody
had not forgotten to bring the proper crimp tool for these
little pins (which then slide into the housing).

Probably a better solution:
Is to use a pre-made female-to-female wire,
cut it in half, strip the ends, slide some shrink-tubing over
the wire, solder the new wire (extension) to the CT's wire,
shrink the tubing in place, and slide the female pins into the
1x2 housing.

 

[garygid]

On February 9th, we will have another OpenEVSE Plus workshop,
at the same convenient location in Cypress, on the East side of
Knott, about a mile south of Katella.

See the SoCal Gathering thread for more information.

 

[GlennD]

I have been using some "F" fuses that I purchased from Ebay. I have found they run very hot and melted a fuse holder. I recommend only US fuses. I use Busman MDL 25A 250V but littlefuse 3AB is also good.

 

[borland]

I have been using some "F" fuses that I purchased from Ebay. I have found they run very hot and melted a fuse holder. I recommend only US fuses. I use Busman MDL 25A 250V but littlefuse 3AB is also good.

Most fuse holders are rated by manufacturer for maximum load. I couldn't find your 'F' fuses on eBay, but was wondering what they might have been rated for.

What size breaker panel are you using that still requires fuses for the L1/L2 'pass-thru' load?

I don't see any reason to provide fuses for the L1/L2 pass-thru since that load is short circuit protected by the breaker panel. The Open EVSE Plus board has two built-in fuses on the L1/L2 input to the AC/DC converter as well as opto-isolation on line voltage sense circuit, but those are for very low current short protection.