Re: Current Sensor
 

Positive, actually, but that's irrelevant because the Victor speed controllers can reverse the polarity of their output in order to run the motor in reverse. In the datasheet for the chip, you'll find that it outputs 2.5V (the middle of the range) at 0Amps, and goes both positive and negative from there, 5V being some full Amperage forwards, and 0V being some full Amperage backwards.

Re: Current Sensor
 

Actually you don't need to solder the 10 AWG wires into the holes. You can solder the 10 AWG wire to a large circular connector, and then you can bolt on the lead. I would suggest using a paper washer on the bottom before you screw the nut on. This is easier than soldering the wires in directly, and you can remove the current sensor more easily.

Re: Current Sensor
 

Why a paper washer? The object is to make a connection with the board, not insulate from it.

Re: Current Sensor
 

Yeah I was mounting a new motherboard today and the places in the PCB where the screws went had the same ring of metal around them as on the sensor PCB.

But the soldering worked pretty well and with the connectors on the ends of the wires it makes it easy to add/remove from the circuit.

Re: Current Sensor
 

You connect the ring terminal to the board, metal to metal, and before you put the nut on, you put on a paper washer, then you put the nut on.

Remember when soldering to add a heat sync to the sensor so you do not damage it. I know that FIRST has suggested using a small piece of aluminum, but I found that I got better results using an alligator clip on the pins that I was going to solder. Also if you mess up and fill a hole with solder, and you still need to put a pin in it, just simply touch your iron to the solder until it turns liquid, and use a high pressure spray of some sort (air or endust) and the entire area is clean; just make sure that noone is opposite of you when doing this cause noone likes being sprayed with hot solder. Wicking could also work to clear out the holes, but it would take longer, and is not nearly as cool :)

Another note of advice, always solder from the bottom of the circuit board where the pins are, and if your solder job is good, it will be shiny, and if it is dull you gotta redo the joint cause you got a cold connection.

Re: Current Sensor
 

I would reccomend a solder sucker or a solder wick. Those tools are very cheap and are a lot safer than an air blast. The alligator clips do work since I used them in my electronics class to solder items. Also, a tool with adjustable alligator clips to hold your project comes in handy.

Re: Current Sensor
 

Garrix,
Just tapping the circuit board on the bench after you heat up the pad works fairly well also. But a better hint is to solder the #10 wires to the board before you add the sensor, that way you don't have to worry about heatsinking the sensor leads.

Re: Current Sensor
 

so is there a posted version of the assembly instructions?

Re: Current Sensor
 

It's now at http://www2.usfirst.org/2004comp/Spe...ent_Sensor.pdf

Re: Current Sensor
 

Is it possible to order the complete kit from Allegro? If not, where can I get the PCB and the capacitor?

Thanks!

Eugene

Re: Current Sensor
 

Can you post a picture of the finished product. We will be building ours tommorrow night.

Thanks,

Phil

Re: Current Sensor
 

thats a lego head :D

Re: Current Sensor
 

I believe I have the current sensor wired up properly but the controller reads a number around 867 and never moves from that, no matter how much current I pass through it. I'm sure the PWM cable to the RC is aligned correctly. I tested the analog inputs with another device and they work fine (0-1023).. if I disconnect it the value floats around as it should, connect it, 867. Any ideas? Is it defective? I heatsunk it while soldering to make sure it wasn't damaged.

Re: Current Sensor
 

First of all use a multimeter to make sure the ends of your wire are actually connected to the big leads (just to make sure). Also make sure the big leads aren't shorted together somehow, thus bypassing the sensor alltogether.

Then try using the multimeter to read the voltage between the output pin and the ground pin as you pass current through the big leads. If your voltage changes but your input doesn't you have a problem somewhere besides the sensor itself.

That's all I can think of right now.

Re: Current Sensor
 

I already checked to make sure all the connections were made properly (end of PWM cable pins to the pins on the chip, big leads to the big leads on the chip), I did not check resistance across the big leads, I will do that today. What should it be? I know it has to be very low because it is an ammeter...