Help with Piglet board???

[jsr]

I purchased a Piglet board from goldserve in his last sale here:

http://www.candlepowerforums.com/vb/showthread.php?t=157776

I unfortunately lost (maybe deleted accidentally) all his PMs informing me how to connect it and what precautions to take.

I will be placing it into an E-Can.

Can anyone help me with the following and any other advice you can give?

1. Which wire is positive and which is negative? One is near the inductor, the other near the chip.

2. Both wires seem to go through the board and make contact with the plated ring on the bottomside. Is the plated ring battery negative (GND)? If so, how is the LED+ and LED- wires isolated from the GND? I recall goldserve saying I have to keep the LED- and GND must be kept separate.

3. If I'm supposed to solder the GND ring to the E-Can, what's the best method?

4. Any other advice is appreciated. I haven't even tested out the board (had it for a while) yet and I've forgotten everything.

Thanks.

 

[ROK]

I have some experiences in Piglet board.

1. Near the inductor side is LED(+) and the other one is LED(-). You can find the letter of LED+ and LED- on the board

2. Both wires are not connected to the bottom GND(-) ring. Keep in mind LED(-) and battery(-) must be separated.

3. My method is as follows;
1) first make a notch on the bottom of CAN.
2) solder the short wire to the notch
3) solder the short wire to the GND hole

4. Check botom of 2 soldered wires before starting mod. Protruding wire can make a short circuit. IMHO to insulate the bottom of 2 wire holes form the CAN is best way. In my experience, Piglet board is not strong electrically. Be careful to mod.

Cheers,

 

[jsr]

ROK - much thanks for the info.

For #4, when you say checked the 2 soldered wires, I assume you mean the LED+ and LED- wires, correct? That's my biggest concern. When I look at the bottom of the PCB, it looks like the wires are not separated and are actually connected to the GND ring. This doesn't make sense. When I search on CPF, it looks like there's been several variations of the Piglet driver as mine doesn't look like the ones I've seen. One I saw on CPF has distinct separation of the conductor to isolate the wires from the GND ring, but mine doesn't. I'll try to take a picture to show.

 

[ROK]

CORRECT!
It is hard to find whether the 2 wires are separated from the GND by naked eyes. So I used multimeter.
My one of 3 Piglet boards has a protruding wire. So I have re-soldered and isolated it with small epoxy.

Goldserve said all boards are checked before send it. But I have a defective board. I am wating his response.

 

[jsr]

I just checked it with my DMM and the LED- is connected to GND, so it is also defective. I haven't powered it on yet luckily or else I'm sure something would have blown since Goldserve cautions everyone about keeping the 2 separated. I'm thinking about cutting the traces to try to isolate the LED- and GND.

 

[ROK]

It shows only 0,2ohm. So you have to measure carefully with good DMM.

 

[jsr]

My DMM isn't good enough (not enough resolution) to measure that low a resistance. I was using the diode check to check for continuity and it beeped when I checked from the LED- wire to the GND ring.

So, it's supposed to read as a connection since the resistance is so low between LED- and GND?

 

[ROK]

You cannot use the diode checker because resistance, between LED(-) and GND, is too low.

 

[Darksky]

Late to the party as usual.
Don't know if this'll help. The piglet (marked Rev1) I have was prewired +ve contact is beside th inductor and -ve is at the chip for the LED as ROK stated. I measured the -ve contact to the ground ring and got 0.02ohm but as you can see from the closeup there is no physical contact between the hole and ground trace. So I'm guessing there is there is some contact through the inductor/chip etc. of the circuit. i.e. If you removed all the components and just had a bear PCB there would be no contact. I haven't wired it up yet as I'm waiting for other bits.

 

[jsr]

My Piglet (don't know what Rev) does not have a defined separation between the through-holes and GND trace. It looks more as if the through-hole is not plated with a ring around it, but the GND trace (outter ring) comes to the edge of the through-hole, so it's a very small unplated area separating the 2 conductors, much smaller than the Rev.1 you show. I tested it out tho and it does seem to work and I did notice the low and high levels, so hopefully all is good. My DMM doesn't have the resolution to measure that low of an impedance...my DMM measures 0.04ohm, but it does the same measurement from lead to lead (so actual resistance is smaller than the resistance of my leads).

 

[goldserve]

It is normal for the piglet to have a 0.02 ohm resistance between gnd and led-'ve because there is a very small 0.01ohm sense resistor inside the converter chip itself.

 

[jsr]

Kevin - thanks for the help. How do you change thru the modes on the Piglet? Right now, it's in the high-low-high-low-high-low mode.