MOSFET Part6 Constant Current Sink

Рет қаралды 16,896

ElectronicsTeaching

9 жыл бұрын

MOSFET pair used to make a constant current sink.

Пікірлер: 19

@guyfradasyl88650 5 жыл бұрын

very WONDERFULL serie of videos. could you continue ? please

@imjustaguy1721 2 жыл бұрын

Yeah man very usefull iv been thinking of connecting 60ish or more LEDs to a constant current supply but not sure how to do that cause they are in series so voltage is like 200V so this helped alot

@mkg4u 5 жыл бұрын

Good...

@secretsather 8 жыл бұрын

I'm coming up with .00808, or 8.08mA for my calculations. That works for both the ((12-vgs)/1000) and the Id = gm(Vgs-Vth).. I think the error occured in your rounding. In any case, this is a great video. Thank you for it! I did have one question, would it be possible/feasible to have a different voltage for the Q1 transisor than the Q2 transistor side or do they have to share a supply? I'd like to have 12 volts on the Vref side, with something a bit more substantial on the mirrored side, say 90+ volts

@electronmath8609 3 жыл бұрын

good lesson

@electronmath8609 3 жыл бұрын

👍❤️

@hansgemerden6089 3 жыл бұрын

great teaching, specially because i want to power a 3000 W/ 240V/dc boiler with PWM and several mosfets in parallel without destroiing them. this is because of the solarpanels use etc. Is there anything else needed to protect them?

@ElectronicsTeaching 3 жыл бұрын

Sorry for the late reply. I'm not an expert on power applications but I would say chose your MOSFETS carefully and make sure they have decent high voltage diodes to protect them. Are you sure you need them in parallel? A single 16A 400V Mosfet should cope.

@shayweiss8101 Жыл бұрын

Really good one! Is it possible to make 0.0-1.0mA voltage controller current source using only one mosfet?

@johnconrad5487 6 жыл бұрын

thats called a current mirror. it is used in designing micro circuits except they are using bipolar transistors and not MOSFETs. you can check almost any e.g. LM117 linear regulator and u will find that circuit.

@SmithKerona 5 жыл бұрын

Yes in the old days bipolar technology was dominant in integrated circuits(L117 design is from 1976). But modern analog integrated circuits almost exclusively use CMOS (complimentary FETs) technology. The circuit in the video is implemented in CMOS technology using P-MOS as the resistor and matched N-MOS transistors as the current mirrors.

@trevorvanbremen4718 3 жыл бұрын

ANY component huh??? Grabs my 'devils advocate' cap... A: 1.2 picofarad ceramic cpacitor B: A 3mm thick sheet of glass C: A van de Graaf generator running at top speed on a nice 'dry' day

@ElectronicsTeaching 3 жыл бұрын

Haha, yep, I agree. I don't think I have made a video yet where I didn't think "I wish I'd put that differently". But, it helps my students get the concept and that's what counts. Thanks for the comment though, feedback is always appreciated.