1. I

    Can I power LEDs of different forward voltages connected in parallel with a single constant current source?

    I am a complete beginner at designing circuits and my English sounds like a 5-year-old talking. So, please beer with me. I was thinking of building an aquarium light. As plants need a full spectrum of light to grow properly, this is the selection of colours I came up with by watching many...
  2. pippinz

    Moset equivalent

    Hi a band colleague smoked his roland 60w blues amp and every forum informs you Roland are not interested in supplying a sm power supply or diagram. The fuse is blown 33 ohms resistor smoked 2 x irf 740s bought to replace The other two are [on] Aff 51 U1620rg kak Does anyone have an...
  3. B

    Buck Boost Converter with MOSFET

    Hello all, Disclosure, I am an electrical engineer but I deal with designing power system for construction projects. I decided to go back for Masters in Power Electronics. I'm rusty with DC circuits. My homework is the same as a previous thread...
  4. alobaolalekann

    Question about Current Draw and Spikes in Half-Bridge Switching Circuit with RC-Snubber

    Is it okay if the half-bridge switching circuit draws up to 100mA from the power supply at 20kHz because of the RC-snubber between the MOSFETs' drain and source? Without the snubber parts, there's no noticeable current draw, but there are many spikes in the output.
  5. alobaolalekann

    MOSFET testing Issues

    I'm currently encountering difficulties in testing my MOSFETs. I am in the process of designing a snubber for an IRF840 operating at 20kHz. Upon attempting to test (drive) the MOSFET, at <= 50% duty, in its basic state without any additional circuitry, I observed a 4V voltage drop from the 12V...
  6. L

    MOSFET - can't control DC Motor

    Hi! I am working on a university project. We are building a vehicle similiar to the BattleBots competition. Everything is working well but I have a problem with a 12 VDC motor controlled with transistor/MOSFET. I am using this motor water pump...
  7. PowerSayan

    Two Switch Forward converter with transient spikes on gate to source voltage

    Good day everyone, so I have a problem with my two switch forward converter. As soon as the current increases at the input from around 200mA a transient/spike starts appears at both the turn-on and turn-off of Vgs. The higher I go and push it the bigger the spikes ultimately get, which is...
  8. Koelite

    Two NMOS in series (steady state)

    Hello, I am stuck on an exercise for a while with the circuit as shown below: We have: \[ V_{DD}=3.3 V \\ V_{tn0}=0.65 V \\ \gamma=0.5 V^{1/2} \\ 2\phi _{f}=0.6 V \\ V_{1}=2.85 V \] The question is: What is the best approximation for V2 in steady state? (a) 0 V (b) 0.65 V (c) 2.2 V (d) 2.65 V...
  9. A

    Newbie question regarding PCB fry.

    Hi all, I am new to electronics and designed my first circuit. However I fried one of my PCB and trying to determine the root cause. What I am suspecting is caused by a diode polarity that I missed. The PCB was working fine for about an hour or 2 without any issues. Then suddenly it stopped...
  10. B

    MOSFET configuration doesn't work on very simple circuit

    I have an issue with a very simple small board I designed in EasyEDA pro (I'm a novice so if the answer is easy, my apologies). I'm not sure I correctly connected the MOSFET in the schematic. Reference to Datasheet: https://atta.szlcsc.com/upload/public/pdf/source/20140314/1457707013919.pdf Part...
  11. Rafaelhdz

    Inverter does not deliver the right Voltage

    Hi, I have been working on a duracell 3000 w inverter model drinv3000, long story short, my dad used it with power tools and now it does not work properly, he measured the voltage, and it delivers 104V AC instead of 115. I already checked almost every component on the board (desoldering them...
  12. dr3iz

    How to connect PMOS in parallel

    Hi, we are designing a 48V high side MOSFET switch and we realised that the our mosfet gets too hot. Our solution is to connect additional mosfets in parallel to distribute the load/heat. But I'd like to ask your how to properly connect PMOS in parallel. I read somewhere that the gates should...
  13. A

    Gate-source voltage waveform in brushless motor drive

    What should be the gate-source voltage waveform of the high side MOSFETs in a brushless motor drive with a trapezoidal control method? Are these parts marked in red in the picture above normal? There is no such thing at the bottom side MOSFETs Schematic: When I reduce the value of R47 and...
  14. jbHardwareDev

    Dual mosfet switch problem

    Hi. I plan to make a pcb that drives peltier and heating pad. Only one of those works at the same time. Load elements are parallel to capacitors. I have very little space on pcb so it would be nice if I could use only one inductor as it is in screenshot. I know it would be easier just to put...
  15. dnflskfk

    How to clear glitch

    Hi Everyone I have designed simple P-Channel MOSFET Circuit! it works well. However, when low Source power is applied(1V), glitch occurs in the output signal. I tried R,L,C component, But it didn't work What can I do to get rid of this? Circuit...
  16. I

    Mosfets getting damaged and i don't know why

    Hi, I made a really simple PWM generator but the mosfet placed in the circuit keep getting damaged even though they are not heating up. The load in the schematic is a 20ohm heating element but i also tried to replace it with much led and resistor but the mosfet still get damaged after 1 or 2...
  17. L

    Variable voltage to light a specific led circuit question

    Hello all , I have this circuit that supposed to light a specific led when varDC/DC is 20V And another led when varDC/DC is 15V and so on .. My question is , why do I have to add the mosfet and the voltage divider at the exit of the comparator (the red mark)?? it seems to me that I can...
  18. pranay1803

    Not Getting Desired output for 2:1 Mux (using MOSFET) in LTSpice

    I was trying to design a 2x1 MUX using a CMOS logic. I have used a 180nm library for the mosfets and made the circuits using Transmission gates. For simulation purposes, I have considered Width of PMOS as 3 times the width of NMOS. When S = 0 then the output should be D0 and when S = 1 the...
  19. Younes Thabet

    Can IGBT gate drivers drive Si, SiC MOSFET, and vice versa?

    Hello All, For example, this gate driver from Ti (UCC21520) can drive GaNFET, IGBT, and MOSFET. But can it drive SiC MOSFET? Or maybe the IGBT Gate Driver (NCV57000) from onsemi, can it drive Si/SiC MOSFETs? why not a generic gate driver that can drive all switching devices? Thank you,
  20. genxium

    Quick doubts on FinFET

    There're many articles and videos in the internet saying that FinFET has a big advantage in transistor density, however it's difficult for me to find an example about how one FinFET's fins are actually connected to other electrodes such that the density is increased compared to using MOSFET. I...
Top