Question Wii Custom Regulators Questions (noob)

[Alvaro]

Ok so I know there is the board in the store but I just want to know somethings about making regulators because I have been reading up on basic electricity etc, and for the love of god I can't understand. I would just love the knowledge.

PTH08080 is rated for resistors with a 0.05W at a 1% tolerance, so a wide variety is accepted (guide I looked at: http://bitbuilt.net/forums/index.php?threads/custom-regulators-an-explanation-and-guide.754/)

This statement has me confused. I get that the tolerance is 1% so to get a 1v it would have to be 872 ohms up or down from 87.2k (this is all in perspective of a 7.4 v battery from the guide and would change if the battery had different voltage right?). And also how would you go about getting that much resistance, would you have to chain resistors, I would love an example of some regulators that are done and which resistors were used to achieve it.

Then my other question would be tied into the .05w its rated as. That would mean thats the max capacity of power it can have and all the resistors I saw had different Watts it was rated at? So it doesnt make sense because for one regulator you need an output of 1.15v at 1.8A which would be 2.07W and thats well over the rating.

Lastly, does the PTR08060 regulator has ratings as well? I would love to say THANK YOU SO MUCH in advance to anyone who answer all my questions so I can understand all of this. I am trying to learn all of this stuff about circuits and it makes me confused. It would help a lot and probably let me have a better grasp on similar situations.

 

[Stitches]

Ok so I know there is the board in the store but I just want to know somethings about making regulators because I have been reading up on basic electricity etc, and for the love of god I can't understand. I would just love the knowledge.

PTH08080 is rated for resistors with a 0.05W at a 1% tolerance, so a wide variety is accepted (guide I looked at: http://bitbuilt.net/forums/index.php?threads/custom-regulators-an-explanation-and-guide.754/)

This statement has me confused. I get that the tolerance is 1% so to get a 1v it would have to be 872 ohms up or down from 87.2k (this is all in perspective of a 7.4 v battery from the guide and would change if the battery had different voltage right?). And also how would you go about getting that much resistance, would you have to chain resistors, I would love an example of some regulators that are done and which resistors were used to achieve it.

Then my other question would be tied into the .05w its rated as. That would mean thats the max capacity of power it can have and all the resistors I saw had different Watts it was rated at? So it doesnt make sense because for one regulator you need an output of 1.15v at 1.8A which would be 2.07W and thats well over the rating.

Lastly, does the PTR08060 regulator has ratings as well? I would love to say THANK YOU SO MUCH in advance to anyone who answer all my questions so I can understand all of this. I am trying to learn all of this stuff about circuits and it makes me confused. It would help a lot and probably let me have a better grasp on similar situations.

Input voltage doesn't affect the resistance value that sets output voltage, they're separate. The tolerance is the max % of deviation from the desired resistance value, but this only applies to the precision of manufacturing of the resistor itself. You can use resistors of any tolerance with the PTH regs, I've had 5% tolerance resistors that were within 2ohms of the desired value, and they cost less.

Regarding chaining, don't. You technically can, but you shouldn't, it's asking for a short. Voltage is a neato thing in that it drops under load, so it's actually better to undershoot the resistance to overshoot the voltage by a little bit. You can undershoot the resistance by 10-15% no worries with the PTH regs, the system will work just fine. It should be much easier to find single resistors within that broader bracket. As for the wattage rating, don't worry about it. Wattage is the resistor's ability to disperse heat, the full current of the reg doesn't pass through the resistor and is unrelated. 0.25w resistors are commonly used and very available.

 

[Alvaro]

Input voltage doesn't affect the resistance value that sets output voltage, they're separate. The tolerance is the max % of deviation from the desired resistance value, but this only applies to the precision of manufacturing of the resistor itself. You can use resistors of any tolerance with the PTH regs, I've had 5% tolerance resistors that were within 2ohms of the desired value, and they cost less.

Regarding chaining, don't. You technically can, but you shouldn't, it's asking for a short. Voltage is a neato thing in that it drops under load, so it's actually better to undershoot the resistance to overshoot the voltage by a little bit. You can undershoot the resistance by 10-15% no worries with the PTH regs, the system will work just fine. It should be much easier to find single resistors within that broader bracket. As for the wattage rating, don't worry about it. Wattage is the resistor's ability to disperse heat, the full current of the reg doesn't pass through the resistor and is unrelated. 0.25w resistors are commonly used and very available.

Ok it makes more sense to me now. Do you mind giving an example resistor for a PTH08080 trying to reach 1v. The desired resistance is 87.2k ohm and it would be better to undershoot it, correct? You would be able to undershoot it by atleast 10 ohms so what resistor would you use for this. Also is there a place where I can browse all the resistors because if you search up something like a 90k ohm resistor I don't see anything, I get something like this https://rb.gy/xglznf so im not sure if they even exist/ what ohm resistors they are. Yet again thank you so much, knowledge is power.

 

[wudopecker]

I personally went to a local shop who had a bunch of resistors coded in little baskets, so i went with my list and picked the ones closest to the one needed for the Pths, for the 87.2k one for example i picked a 86.6k ohm.