Celllog alarm output questions

[jdcburg]

Can someone explain to me what happened here: I have a celllog 8m that I wanted to use as a LVC with 8 Thundersky 20ah cells. I have an inexpensive JC-116 controller that has an ignition plug and a plug for a brake switch. The ignition plug requires a closed switch to operate (I use a bent paper clip) and the brake switch is normally open – it kills the motor if it’s closed. I tried the brake plug with a bent paper clip and it works as it should so I thought either of those 2 places would be a good place to connect the celllog external alarm output for a LVC - NO for the brake switch or NC for the ignition.

I don’t read schematics and I don’t do that well with Chinglish. I have attached what I think are the relevant schematics and explanations of the alarm circuit from the celllog manual. When I read the instructions about the “short circuit,” I thought the alarm circuit would make a switch across the red and black wires, depending on the NO/NC setting and alarm state. First I tried attaching the wires to the brake connector with the alarm output NO position. The motor ran normally. Then I switched it to NC, which I thought would cut the power, but it didn’t. Next I tried the probes of my digital multimeter in the ignition plug. The voltage was 27.02. The DC milliamps on the 200 ma setting read 37.9-38.0 whether the motor is turning under power or not. Those numbers are well below the celllog limits of 50v, 500 mA. So then I decided to try connecting the alarm output wires to the ignition plug while the celllog was still set at NC. I plugged the black wire into one side of the ignition plug. The red wire was not plugged into anything. I happened to pick the + side of the ignition plug. There was a giant spark. I jumped pretty good. I suspect a few more than 38 mA passed through those wires at that instant. BTW, the bent paperclip has never sparked when I insert or remove it. I’m guessing the black side of the alarm circuit is not isolated from the negative battery terminal when the alarm output is set to NC? Both the controller and celllog seem to work fine but the alarm output circuit appears to be fried. I have ordered a new celllog and will probably go with a external buzzer or LED but I wonder (1) why the brake circuit wouldn’t cut the motor when I switched the alarm output to NC and (2) what happened with the ignition plug? Thanks for any advice - jd

 

[jateureka]

Hi,
Your controller 'ignition' plug is likely used to switch the battery voltage on/off to the controller.

Your brake plug is likely switching a logic level either to ground or to Vcc.

Your cellog seems to provide an open collector output to ground. You could use it to operate a relay and connect the relay contacts to your ignition or brake circuit which would now be isolated from the cellog.

 

[ktronik]

Hey

I two was looking at the ALM output & wondering if it could be used as LVC connected to the 'brake cut' input, after all its fully programmable...

I would have done some of what you have done...if that did not work I would then look to build a 'opto' isolated type switch...(opto's easy to get & easy to wire)

So the ALM output would hopefully fire the LED inside the opto, & this in turn connects the 2wires of the brake cut together...as long as you can hookup the LED on the celllog side (ALM) & not fry it, may need a ballast resistor to keep it to 20ma across LED, I think it would work...

if you get to try this first let me know how it goes...

best

Ktronik

 

[GGoodrum]

The negative side of the CellLog is not isolated from the pin1 JTS-XH balancer plug input, so unless you were only using this with the first 8 cells in the pack, you can't use the alarm output to pull down the brake line on the controller. These need to be opto-coupled. Here's what I do:

View attachment LiPo CellLog LVC-HVC Output.png

 

[jdcburg]

Thanks all. The celllog is on backorder from Hobby King so it might be a while. In the meantime I'll be careful about not running the battery low - jd

 

[ktronik]

OH YEAH~!!

thanks for the pic!!


so if you use it, I take it works no probs & is reliable for the LVC function??

thanks

Ktronik

The negative side of the CellLog is not isolated from the pin1 JTS-XH balancer plug input, so unless you were only using this with the first 8 cells in the pack, you can't use the alarm output to pull down the brake line on the controller. These need to be opto-coupled. Here's what I do:

 

[The Journey Guy]

If "The negative side of the CellLog is not isolated from the pin1 JTS-XH balancer plug input" then why do you make a connection to pin 1 from the alarm port?

Maybe this is where I've been going wrong with my thinking? Do you mean to say that the alarm port is not a 'switch', in the true sense of the word, as in a simple blade switch? I was under the impression that the alarm port completed an input path. I did not know that it, instead, took the input signal and dumped it to Pin1 neg ??

Am I right, am I wrong? Does anyone know?

TJG

 

[jateureka]

Based on the info in the first post, no the cellog alarm output is not a a simple switch contact. It seems to provide an open collector output via its internal transistor that will either sink a signal to ground or let it float.
Edit: ground appears to be the negative terminal of BT1, based on the above posts.

If you want mechanical switch contacts you will have to use that relay circuit or something similar.

 

[The Journey Guy]

Based on the info in the first post, no the cellog alarm output is not a a simple switch contact. It seems to provide an open collector output via its internal transistor that will either sink a signal to ground or let it float.

If you want switch contacts you will have to use that relay circuit or something similar.

Sorry for the late reply, had another operation yesterday.

Anyways, thanks for the further info, and I'll keep at it till I understand how it works.

TJG (journeying back to bed for now)

 

[jdcburg]

The Celllog 8m is still on b/o but I am trying to figure out what I can do with this, and how to do it.

unless you were only using this with the first 8 cells in the pack, you can't use the alarm output to pull down the brake line on the controller. These need to be opto-coupled.

I am only using 8 cells so that may simplify it. Can someone explain in plain English how to do one of the following: (1) use the brake line on the controller as part of an LVC, (2) hook up a flashing or steady warning light as an LV warning or (3) hook up a louder buzzer as an LV warning. I would prefer 1 of the first 2 if they are not a lot more complicated. If I understand the GGoodrum diagram correctly, the black wire connects to a negative wire. The red connects to a resistor, a diode and an opto device then to a positive wire. The opto device looks like it has 6 terminals so I would need to know how to connect it. I have a 24V Bosch type relay that I could use if it would work. I think the celllog would be set to NO and the relay to NC?

I have a local Radio Shack or I can order parts if necessary. If you could tell me what parts to get, that would also be very helpful. Thanks - jd