Will the above circuit work well in practice for a programmable voltage source? The zener would be a similar idea to shunt the current for over-voltages. I am in need of a medium power programmable voltage source and this seems to fit the bill while being simple.
Yes, great catch. They did leave those out--and that's the tie-in to mpm's free energy machine, the centerpiece of our new green/renewable feelings-based energy agenda.
Okay, you haven't gotten many straight answers, so I'll take a stab.
No, your circuit won't work. The LM339 is a comparator; it'll oscillate in that circuit. The MOSFET might oscillate too.
You can use an LM339 as a lousy op-amp, but it'd be better to just use a decent op-amp. Or an LM317.
You'd get more sensible answers if you showed input and output nodes and said something about your goals and needs (accuracy, range, power output, load, etc.)
Well, I figured since you guys are so intelligent you would be able to figure out what is going on. It is suppose to be a comparator and not an op amp. It is not a difficult circuit to understand. Seeing how rude the people are here it's not even worth trying to explain. I'll come back in another two years and maybe the trash will have been taken out. If anyone can't figure out the circuit then maybe they need to go to sci.electronics.basic and hang out for a while. The circuit works fine in practice and I'm not sure what your talking about with oscillation. The comparator should oscillate to some degree and with a bit of built in hysteresis it should be fine. Do you seriously thing that the opamp/comparator matters? That alone tells me either you guys don't care to pay attention and just want to be jerks. I used the lm339 because that is what multi-sim had. Abstract thinking is important but I guess they don't teach that in repair school? See you guys in two years, hopefully you will have grown up by then.
I don't understand how a 10k pot will handle 100 volts without burning up, or why a circuit that's supposed to be programmable doesn't have a programming input. Or an output.
I don't understand why you'd think that the LM339 has built-in hysteresis--it doesn't.
I don't understand why the apparent reference input to this voltage regulator from hell is nailed to +5.5v, which makes the whole thing look kind of useless.
I don't understand why you're using such a complicated circuit to perform such a simple function so poorly.
I don't know why you had to go to all this trouble just to fry a pot and a zener diode--is it a race perhaps? To see which one will smoke first?
No no no...that's not the right attitude.. . You're getting free advice! You got my free 30 second analysis..You get what you pay for..
You'll peak interest and get more feedback if you format your schematic for the purists and list advantages and write a summary. Otherwise you'll just get mush. GIGO
Heck, just list your specs..Some guys on here have done every fkn way to do a circuit. btw..I hate circuit analysis and prefer circuit synthesis.. Circuit synthesis is like being an artist. Circuit analysis is like being a janitor that cleans up a mess... Sorry but when I looked at your circuit, it seemed like a janitorial operation.
D from BC snipped-for-privacy@comic.com British Columbia Canada
(sci.electronics.basics added, at Dookie's suggestion)
Dookie wrote: > On Nov 7, 2:34 pm, James Arthur wrote: >> snipped-for-privacy@gmail.com wrote: >>>
formatting link
>>> Will the above circuit work well in practice for a programmable >>> voltage source? The zener would be a similar idea to shunt the current >>> for over-voltages. I am in need of a medium power programmable voltage >>> source and this seems to fit the bill while being simple. >>> Thanks, >>> Joe >> Okay, you haven't gotten many straight answers, so I'll >> take a stab. >>
It actually is difficult to understand.
I don't understand how a 10k pot will handle 100 volts without burning up, or why a circuit that's supposed to be programmable doesn't have a programming input. Or an output.
I don't understand why you'd think that the LM339 has built-in hysteresis--it doesn't.
I don't understand why the apparent reference input to this voltage regulator from hell is nailed to +5.5v, which makes the whole thing look kind of useless.
I don't understand why you're using such a complicated circuit to perform such a simple function so poorly.
I don't understand why you had to go to all this trouble just to fry a pot and a zener diode--is it a contest? A race to see which one will smoke first?
If it works fine in practice, why did your original post ask us if it would work in practice? It's really goofy, but I suppose it might regulate. Some.
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