JShaw...WT28p set up. with a nano, and BTW this schematic DOES NOT CONTROL the BuckBoost with PWM LED fading. but it will turn on the buck boost, and turn it off, meaning- no FOC and no blade up or down. effect. just on/off LEDi can't get PWM to work with a mosfet if i move it to the LED Vout side of the Buck Step down.i have since moved my arduino Pin that goes to the mosfet to Pin 11 for PWM, tho i haven't gotten fading to work with a Buck, and the 2 sensors to non PWM pins. it's arbitrary. you can do what you want. also some people put a 1kohm resistor from pin 1 to pin 3 of the MOSFET to crash the PWM signal to 0 (Ground) for Digital (HIGH/LOW) mosfet switching, you do not need it.
If i send 8.2v and unrestricted current to my LED it will fry it.PWM does not limit current. it really doesn't limit voltage either, but when you go from 0 volts to 8.2v 250 times a second,.. it starts to average to lower voltages. I COULD put 1 ohm / 2-3 watt resistors to my LEDs,.. what is what a lot of (maybe even most) people do here to protect their lights. That could be wasting 40% of the batt power to heat loss. Bucks waste maybe 10% or less of power in the conversion process. and they can drive other components. good review of LED control. I read it for the first time just now, but have been tossed most of these crumbs via the folks here and old roommates from college who are versed on the topic of Computer Science, Control Systems, and Electrical Engineering.http://www.digikey.com/en/articles/techzone/2010/apr/how-to-dim-an-ledBuck up/downs- or what my smarter electrical engineer pals tell me are called, constant current induction devices- limit current and convert voltage to the desired Max levels, thru either custom set up, or the ones i use have mini potentiometers for adjustment.Jake-----I can't find half of this stuff anywhere ELSE but Ebay. If i do, it is often 10X the cost. and yeah,.. it is hit or miss with 75% of it. i am tired of getting devices with ratings and specs that after testing prove otherwise. This is a great question. i hope someone comes forward with another provider.
You know, it occurs to me that your fading of the LED might work better if you supplied constant power to your Buck converter and moved your transistor to be between the LED and the converter.
Sorry, my mistake, I did not pay attention to your supply. But, what about the following: you only use 1x3.7V supply (instead of 2) and use a boost to give 5V to your Arduino. Then connect your single LED to the 3.7V with PWM. Additional advantage: less space eaten up by batteries (they are big or have limited capacity) and a smaller boost, because the "logic" does not eat so much compared to the HP-LED's.
yeah,. good eye.this diagram is for NO PWM fading,. as the mosfet arduino pin isn't even PWM. i have rearranged things as a told jshaw for pwm.i do have a new set up with an additional fet tween the vout of the buck and the led. still no good. i orered a new buck. maybe this one is bad.yup. you are correct sir.
Try putting your nFET on the negative side of your LED instead.
i have the neg out of the buck,. on the.. uh... source pin. right pin. i have the neg of the LED on the drain. middle pin.you think switch that?
That sounds right. Not sure why it doesn't work. Sorry, man; I'm stumped too.
So...one step forward, one step back.I printed a hilt in three pieces using a 3D printer (standard PLA) and had it at 30% infill with triangular structure. the outer wall is at 1.65in and the inner wall is at 1.35in, so a total thickness of .3in, and now the results....the physical pieces can take a major thrashing without cracking, breaking or compressing. Had my son hit the bladeholder directly at varying degrees of force and nothing. the inner core where the blade rests had no damage either. the metal screw I used as a retention piece was fine and unscrewed and rescrewed without a hiccup (printed the threads in the design).you may be asking yourself...how do you know what the inside looks like and that there is no damage? well....that's because the hilt snapped....into three pieces...right on the 3-d printed threads. I was using 1.43inx12 ANSI threads and they couldn't take the force of the vibration from the impact. the rest of the body was fine. I am thinking about making the parts slide inside eachother until they catch and holding them together with a couple of machine screws. unless anyone has a different suggestion?
So...one step forward, one step back.I printed a hilt in three pieces using a 3D unless anyone has a different suggestion?
I am using Fusion 360 to model and Simplify3D to slice and print. I am printing it cylindrically, that's true, so do you think if I printed it on it's side it'd be stronger? I was printing it straight up and down.