1k resistor added, glad I haven't damage my board yet. added 3 100v 470uf cap
capacitors to the output, much more stable now with fluctuations of +-4v with no load
voltage drop is now only about 10v (60v down to 50v). hopefully this can be further improved, im going to try changing to some different diodes
That is a very high voltage mosfet with an RDS(on) of 1.1 ohms (quoted at 10 volts Vgs). That is a relatively high resistance. Incidentally, it is not the mosfet indicated in the schematic.
You'd be better off with a logic level mosfet driven directly from an Arduino pin (push pull output) instead of with that intermediate npn transistor and the pull up resistor. With higher switching frequencies you have to start taking care that the mosfet is cleanly switching off and on and not lingering in a half on / half off state.
100 ohm at 60V is 0.6 A
Coming from 5V you will need 0.6*12 = 7.2A at least.
If that all goes through your 1.1 ohm fet, it does get hot....
And that is assuming the fet is fully on... (it probably is not)...
hello, i just built a 12v to 60v stepup circuit with a spare 555 i had, if anything it builds up to 60v much slower than the arduino feedback buck boost converter, also with a 1k load it drops from 60v to 10v, in comparison the arduino boost circuit is doing much better with only 10v drop from 60v at 1k.
Im going to take a guess that its the mosfet thats the issue as it just melted to the heatsink as im typing this.
got a cheap order of some better rated mosfets on the way(nce8290), hopefully these dont melt too, they seem better suited.
im going to stick with using arduino for feedback, the 555 didnt do as well for me.
the 555 circuit i just used:
The test, though, or one of many, is how well it does with a varying load - a quickly changing load. (How well does it maintain, recover?)
[quote="loveofsparks, post:9, topic:1173243"]
60v from a buck converter is perfectly possible, already have one tl494 based 12v to 60v stepup however i need two step-ups and im a little tight on budget right now this leads me on to what the load is going to be, im going to be powering a +-60v amplifier which will be drawing about 500w, im doing this by using two isolated 12v 30A smps power supplies going into two separate boost converters. This means each boost converter will be handling 250w.
Are you sure you know the difference?
Yes very true especially as i will have it hooked up to an amplifier, the current draw fluctuates greatly so im going to be needing a very stable output, luckily the chipamp im powering has a fairly wide voltage range from 50v to 100v (+-)
Ah sorry that was rushed. Correcting to buck-boost converter
Interesting.
Is the 555 running at the same Freq as the Nano.
What is the Resonant Freq of the 80uH coil?
this conventer is bad schematic, its dont work