SOB 1000 converter question

[Nake]

I am wanting to buy an SOB 1000. When looking in the Shoppe's catalog I see two 0.10 resistors are needed to achieve this drive level. Are these resistors already soldered in to the board or do I have to buy them seperate and do it myself? I am also asking this question about the Nexgen 1000 since I want one of those also.

 

[Ms_SS]

There is a solder on option when you buy the converter.

 

[KrisP]

You can buy a SOB 1000 which already has the resistors on it to set 1000mA...

OR

You can buy a SOB BLANK and choose which resistors you want soldered on.

 

[wildstar87]

I also had a question on this. The resistor table only lists out to 1000ma. If I wanted to do 1200ma or max it out to 1500ma I'm not sure which ones I would get.

The blank lists options for .05 on the resistor, and I tried to use the resist calculator they have there, but it doesn't have that small an option to use for calculating, I guess because it's probably older code.

My guess was like .10 for R1 and .05 for R2 to make it drive 1200ma, and .05 for R1/R2 to drive 1500ma.

Can anyone give me the real specs I need, or did I guess right?

 

[mfrey]

As far as I'm aware the calculation goes as follows to determine the drive current:

(.05/R1)+(.05/R2)=current (A) to emitter

So, to get close to 1200 mA you will need a .05 R1 and a .18 R2. [(.05/.05=1) + (.05/.18=.278)] = 1.278 A or 1278 mA

Someone please correct me if I'm mistaken.

Edit: You can actually get closer to 1200 mA if you opt for a .22 R2. That gives you 1227 mA paired with a .05 R1. To go a bit below the target drive current, a .27 R2 gives you 1185 mA.

 

[wildstar87]

Thanks, I noticed that they had a formula similar to that listed on the description at Sandwich Shoppe. Where does the .05 come from?

Can anyone else verify that this is the correct calculation for me to use? Thanks!

 

[Ms_SS]

Resistor Calculator

0.05 = 1000mA plus a resistor below

0.10 = 500mA
0.22 = 223mA
0.27 = 185mA

Play with calculator for other values