current

Hi readers, When I used this IRF 3205 which has high capacitance between the Gate-Source of the mosfet, whenever I add a lower pull-down resistor, the switching becomes faster and faster (visible nice square wave). For my case, for IRF 3205 to fast switching at 20kHz (nice square wave), it would...

Hi, is there anyone having this PS 2501 optocoupler library from LT Spice. Pardon Me, I couldn't find on the internet :). Please attach it below. Thank you

Dear readers, Above is taken from here . Can anyone recommend transistor Q1 (npn) and Q2 (pnp) to me for driving a mosfet at a 100kHz or higher. What are some of the common best fast switching Q1 and Q2 that can handle high current and high frequency PWM at its base ? Thank you :)

Dear Readers, I got this PS2501 optocoupler datasheet at here. In the image shown, the rise time and fall time is microseconds and I am afraid it's not suited for my needs as it will produce some switching losses in H-bridge circuit running at 100kHz minimum. Are there any very-high speed...

Hi readers, :) I found this at Click here This is an example of a disconnect and reconnect circuit using NE555. This means that the state of load will be (High, then, Low, them High). However, when I simulated using LT Spice it just give me (Low and High only). Does anyone know how to make the...

Hi People :), The reason why I will be needing an oscillating dc waveform is because I need it to be fed into the input of a comparator to produce high frequency square wave dc signal. I built this Wein Bridge Oscillator and it works fine to produce quite a high frequency sine wave. However, I...

Hi readers:), When decreasing R1 value, output frequency will increase. However, I get bad waveform when high frequency. How do I get a good square wave (100kHz) using this LM 741 chip that I bought? Simulation is attached below for your reference and modification to the answer :)

I have a similar question to click here. However, in my case i am using ne 555 for logic gate inverter :). I have generated the complementary PWM and it works totally fine. My question is how to add a dead time between the pulses. From click here, people suggests to use an RC network, how do I...

Hi People :), This is a design I saw at here. Does this highlighted part a tiny step-up voltage converter after it has been stepped down by the transformer in order to prevent voltage drop when a heavy load is connected? Thank you

Hi People:), I am trying to build a synchronous step-down converter but my LT spice simulation shows poor efficiency. The picture above is at Here . I have attached my LT spice below for reference. May I know if this is the right way or anyone can correct my LT spice file and send it in the...

Lithium ion cell are charged at 5V and 2A max. Following Ohm's Law, 5V/2A would mean at least a 2.5 Ohm internal resistance of battery. However, Lithium ion internal resistance is only about 0.28 Ohms. How is that possible :)?

I have a relay but rated at 3A, 30V DC only similar to this. When I connect the Pole and NC directly using a lithium ion battery (4V), a fire occur and it shortcicruicted. However, when i measure the resistance betwwen 2 pins (Pole and NC), it reads 16 Ohms. What should i do :) ? Thank you for...

Hi, if I use a 5V 30Amps Power Supply Unit to plug into the input of this Lithium ion battery charger module, is it fine since it will draw a limited output of 1A to charge the battery which it requires right ?

Hi People :), This is a step up dc to dc converter. This schematic inputs a 15V and outputs a 22V DC. However, I want the input range to be between 3V to 50V and all gives the same constant 22V DC output current. How can this be done with UC 3845. I have attached the schematics below and spice...

Hi readers:), Click here . This link refers to making a lithium-ion battery charger using a BC 547. Question: How efficient is this circuit in (%) that is useful output power/ input power to charge a battery? I am planning to build a 4.2V charger but with a much higher ampere limit by...

Hi readers, is there a P-channel Mosfet with Vds of -400V but has very low Rds(On) because I want an efficient mosfet ? I a planning to power a 400V device and its negative terminal must be connected to ground (That's the reason why i use PMOS and not NMOS). I find a lot of NMOS that can...

If I have a 4W transformer that has high inductance, thick windings, (4V ,1 A) and converted to DC via a rectifier, in order to charge a lithium ion battery (low internal resistance) , will the output will still be slightly less than 4V or will it be very low (close to 0 which makes it...

Hi readers :), Vin is fed with the PWM signal coming from an op-amp to be amplified and fed into the load R1 (1 Ohms). The purpose I design this is I want the voltage source to be a constant 5V which is independent of the load (1 Ohms or 100 Ohms). So basically, this circuit has an op-amp which...

Hi readers, is this the correct way to power a PMOS mosfet? I am unfamiliar with PMOS but quite familiar with NMOS. Question: How to use PMOS to power a 10 Ohm Load? Thank you I attached LT Spice files below. Help me understand by attaching or posting a new schematic :) Thank you and have a nice...

Hi readers, I am doing an Op Amp voltage regulation of voltage drop across load. As you can see from diagram, I have a fluctuating_Vin (0V to 50V) and I want the voltage drop at load (100 Ohms) to be the same (14V) at all times no matter whether input voltage is 20V or 30V or 50V? Note: I...