Fechter's Throttle Interface for RC controllers

[deecanio]

you sir are a gentleman
i'll put $50 to go with Matts $50 :wink: so we have $100 already - anyone else want to help some, doesn't have to be as much but thats a great start? what's the cost of a servo tester and bec anyway?
cheers Matt,

D

 

[Ypedal]

I'm in for 20 $ !

Mr. F .. we need a paypal Addy here !! ( Heck.. with all the help you and Gary have donated, i'll pony up 20$ towards whatever you deem worthy , this project or not ! lol ) :wink:

 

[deecanio]

one love Y!!!!

 

[MitchJi]

$15

 

[recumpence]

I have John Holmes' paypal (I just sent him PP the other day for a HV110 ).

When we get the right amount ($200?) we can paypal John directly assuming he has more in stock.

Matt

 

[Mr. Mik]

I'll throw in US$20.-

 

[etard]

I got $15 to throw in the mix. It's an honor to be in the company of such generous fellas. If John is out of stock, I can send mine until he restocks his inventory too. I am anxious to get this board, its like the last link in the evolution of rc powered ebike.

 

[deecanio]

Hi All,

thank you very very much, generous fellas indeed
Does anyone want to PM JRH and see whats what? he may even donate postage :lol:
I make that $170? i think JRH charges $184 so we are more or less there already, thanks for the support guys, immense !!

OK anyone want to run with the order?

Cheers all,

D

 

[fechter]

Wow!, you guys are too much.
If I had any money, I'd just buy one. Unfortunately, I don't. I also have very little free time to work on these things

Here's what the prototype board looks like in the test configuration:

Close up:


A few things need to be changed, like the voltage regulator transistor needs to be much larger to handle the required current. I'm also planning to rotate the orientation of the main capacitor mounting holes to allow mounting them flat against the board or standing up as shown. Mounting them flat will reduce the height of the board and allow you to glue them down to resist vibration. The main + and - connections will be on opposite sides of the board rather than next to each other.

I'm using the large potentiometer for testing, but you could use a board mounted trimmer to adjust the current limit also.

 

[deecanio]

WOW

it looks great Richard, adjustable current pot would be awesome too.
How do you want to do this?
Maybe the easiest way is to post up your paypal account and we (the people ) will transfer to you and you can order OR
i'll mail JRH and we can pay him direct and just ship to your door? whatever's easiest for you Richard, and again thank you very much for making this for us :wink:


**EDIT**

i mailed JRH to see about availability so i'll post up once he replies.

Cheers,

D

 

[etard]

Great! So this board is going to take the full load of amperage that the HV110 will handle with no need for a BEC? Oh yeah, you guys probably know this already, but make sure your paypals are withdrawn from your paypal balance or checking account so Richard or John don't have to pay all those damn paypal fees.

I wonder how hard it would be to set this board up to be like a Wattmeter and send all the info to a tiny digital readout like the Elogger.

 

[j3tch1u]

i'll chip in 10 bucks

 

[MitchJi]

Hi D,

I make that $170? i think JRH charges $184 so we are more or less there already, thanks for the support guys, immense !!

i mailed JRH to see about availability so i'll post up once he replies.

i'll chip in 10 bucks

Offers are still coming in. Maybe if you wait a few days to place the order you can make a profit

It might be a good idea to check with JRH on the warranty coverage in case Richard fries it.

 

[northernmike]

Count me in for $20!

 

[deecanio]

Hi northernmike,

Thanks very much for your genorousity
We are just waiting for JRH then we will order a spanking new 110 and send it to Richard, again massive thanks to all that have helped this happen

Cheers,

D

 

[MitchJi]

Hi,

Can a good (sparkless) battery disconnect be easily integrated with this interface?
http://endless-sphere.com/forums/viewtopic.php?f=11&t=1090&start=15&st=0&sk=t&sd=a

The big spark you get when you connect the batteries is tough on connectors and switches. Even big ones.

One way around that is to use a precharging circuit. Basically the same thing scottclarke is talking about, but a bit more refined.

Here's the circuit I use on my Vego. I'm using a 24v, 70amp relay from Allelectronics (around $5). The keyswitch gets turned on first, which charges the capacitors in the controller through the 1k resistor. It takes about 5 seconds for the caps to charge. Then I can turn on the kill switch to close the relay, which will only have a few volts across it at that point, minimizing the arcing.

An additional feature of this circuit is if there's a short in the controller (blown FET, etc.), the capacitors won't be able to charge, and the main relay won't be able to close.

Another nice feature is when the keyswitch is off, the controller is completely disconnected from the batteries, minimizing battery drain during storage and reducing the chances of a power line spike getting through the battery charger and zapping the controller (I've heard several reports of this happening, one that resulted in a spontaneous full throttle condition. Imagine your ride suddenly taking off in your living room for no apparent reason ).

The 1k resistor should be able to take full battery voltage without overheating. 5w is good for up to about 72v.

The resistor on the relay coil will be necessary if the relay coil is rated for a lower voltage than the battery voltage. The value of resistor is chosen to provide the correct voltage to the relay coil. A 100uf capacitor can be put across the resistor to give an extra boost to pull in the relay, allowing a slightly lower voltage to hold the relay in.

Can a reliable Kill Switch (remove all power from the ESC) be easily integrated with this interface?
http://endless-sphere.com/forums/viewtopic.php?f=28&t=7680&p=115810&hilit=kill#p115810

I spoke with Bernie at Castle Creations at length about this a while back. He said they looked into it and found a kill switch normally would work fine. However, he said that it is possible for the ESC to get confused by such an abrupt signal and could go into fixed full throttle. So, I never went that route. On my bike, I have the battery disconnect plug in very easy reach and I practiced getting to it quickly.

I agree a decent solution to this is needed.

Matt

 

[northernmike]

Why not just a big switch? Like this one, from West Marine? Or am I missing the point?

300 amp continuous rating for outboards and small inboard engines

Mini battery switches for outboard and small inboard systems are just 2-7/8" square but rated 300A continuous/500A intermittent/1500A cranking at up to 48V. Ignition-protected and safe for use aboard gasoline-powered boats. Long 0.870" one-piece copper studs accept multiple cables. Case design allows surface, front panel or rear panel mounting. Tactile textures on face let you know the knob position by feel. 6005 model has a removable key which remains positively retained. Snap-out isolator covers and label set are included.

* Alt. Field Disc.: No
* Continuous Amps: 300A
* Maximum Momentary Rating: 1500A
* Switch Material: Reinforced Polycarbonate
* Terminal Material and Size: Tin-Plated Copper, 3/8"(10mm)
* Switch Dimensions: 2.85"L x 2.85"W x 3.068"H
* Approvals: UL Listed. Meets UL 1500, SAE J1171, CE
* Warranty: Five years

 

[etard]

Mike,
We need something that interfaces with the ESC which usually gets it's signal from a RC transmitter in pulses. The pulses vary from 1ms (milisecond) to 2 ms, where ebikes use a potentiometer or hall sensor. The problem is converting this 1 volt (off) to 5 volt (full throttle) way of controlling throttle to be sent in pulses (Pulse Width Modulation) to the RC controller, so that we can use or throttles in this application. Somebody correct me if I am wrong. :?
Besides that, the switch is HUGE.

I found this guy on Instructables (my new favorite site) and he came up with a way to do this using an Atmel microprocessor. He also built a really cool Razor, so I invited him here hopefully he will bite. :lol:

http://www.etotheipiplusone.net/?cat=28

Very stealth 1000 watt motor in the wheel

 

[Mr. Mik]

Hi,

Can a good (sparkless) battery disconnect be easily integrated with this interface?
http://endless-sphere.com/forums/viewtopic.php?f=11&t=1090&start=15&st=0&sk=t&sd=a

The big spark you get when you connect the batteries is tough on connectors and switches. Even big ones.

One way around that is to use a precharging circuit. Basically the same thing scottclarke is talking about, but a bit more refined.
.........
Another nice feature is when the keyswitch is off, the controller is completely disconnected from the batteries, minimizing battery drain during storage and reducing the chances of a power line spike getting through the battery charger and zapping the controller (I've heard several reports of this happening, one that resulted in a spontaneous full throttle condition. Imagine your ride suddenly taking off in your living room for no apparent reason ).

The 1k resistor should be able to take full battery voltage without overheating. 5w is good for up to about 72v.
.......

.........

Matt

Thanks, Mitch, for linking to this; and thanks Fechter, for explaining this and the schematics in the linked post!

It helped me understand one of the main problems of the Vectrix: High self discharge rate!

Details on V: http://visforvoltage.org/forum/5304-undead039s-experiences-new-firmware#comment-34244

 

[fechter]

A big thanks to all who have offered to contribute to the 'research fund'. If anyone has a lead on a used 110HV for cheap, that would work for me. I just really hesitate to borrow one since there's a good chance I could smoke it. I also can't promise anyone a free unit, though I am willing to break even the cost for contributors. Somewhere down the road, if I can actually make a profit on one of my projects, I won't need to solicit donations. For now, I'm broke.

I love the Mars powered electric shopping cart in the link:

As far as the main power disconnect goes, you should either use a switch, relay or connector of some sort with a precharging resistor.

Gary and I are working on an active cutoff circuit to interface to our BMS for a different application. With a little modification, the active cutoff could be used in place of a main relay, allowing control with a small switch and wires. This takes quite a bit of silicon ($$$) depending on how much current you want to run, so I think it will end up being a separate board. The advantages are it does not waste much power, has no contacts to weld, and is relatively small. A big switch or connector will probably be quite a bit cheaper.

The throttle interface circuit also has a tie in for the LVC from a BMS, which would be better than dumping the power input. Both the LVC and brake switch inputs are ramped so the controller does not see an abrupt change in signal. This should prevent any undesirable behavior.

 

[swbluto]

Mike,
We need something that interfaces with the ESC which usually gets it's signal from a RC transmitter in pulses. The pulses vary from 1ms (milisecond) to 2 ms, where ebikes use a potentiometer or hall sensor. The problem is converting this 1 volt (off) to 5 volt (full throttle) way of controlling throttle to be sent in pulses (Pulse Width Modulation) to the RC controller, so that we can use or throttles in this application. Somebody correct me if I am wrong. :?
Besides that, the switch is HUGE.

Correct. It's also thought that current limiting is needed but you shouldn't as long as you're not using partial throttle and you have the batteries that can dish the power out(And a motor that can take it and a controller with enough input capacitance to not blow it up)!

I found this guy on Instructables (my new favorite site) and he came up with a way to do this using an Atmel microprocessor. He also built a really cool Razor, so I invited him here hopefully he will bite. :lol:

I don't believe so. I think he just built a servo tester circuit he found online. I am THE ONE that used the atmel processor. More details about my build can be found at http://endless-sphere.com/forums/viewtopic.php?f=12&t=7638&start=30 .

 

[MitchJi]

Hi,

A big thanks to all who have offered to contribute to the 'research fund'. If anyone has a lead on a used 110HV for cheap, that would work for me. I just really hesitate to borrow one since there's a good chance I could smoke it.

Would a lower amperage model like an HV-30 work just as well for testing? It costs about 1/2 so blowing it wouldn't be as expensive.

It might also be easier to find a smaller model used.

 

[northernmike]

Personally, I would prefer if this thing was tested with an HV 110, considering this is going to be it's intended use. How will you see how the current limiter works if you're only capable of drawing 30A ?

 

[deecanio]

Hi,

yes agree with mike there, with so many using the 110 we need to see a 110 tested hard
the only thing i'm waiting on to send one to Richard is JRH :lol: holla if you see him :wink:

cheers,

D

 

[Ypedal]

Hey Mr.F, if you have a paypal addy.. post it up. Instead of trying to funnel funds may as well just send it direct to you .. if some extra happens to show up.. well.. Bonus ! :wink: