# Search results

1. ### DSPIC33F Advance PWM fonctionnality (will giv all my points)

Hi everyone, I am working with the DSPIC33FJ16GS502 for a little while. I would like my PWM to trigger an ADC conversion but without success. Anyone know how to do ?? I've been looking around the Special event trigger and the dedicated trigger but without succes. I know my ADC interrupt...
2. ### How to choose a LCR Meter

diy lcr meter Hi everyone, I want to buy an LCR meter, I am a young SMPS engeneer and I want to test the transformer, inductor and capacitor I am using, my switcher are operating from 20K up to 1MHz. I also like to construct guitar and power amp, so I want to check the impedance of my pickups...
3. ### Inductor meter, physical principles

make inductor meter Hi, I would like to make an inductor meter. my circuit is just a mosfet driver 6A driving an inductor with a square wave and a resistor to sense the current. The frequency may go up to 1MHz. I got op-amp to output the differntial voltage and current (these a rated 3,9GHz)...
4. ### Wire Gauge For SMPS transformer

wire gauge for transformer How do we choose the wire gauge in SMPS transformer. I know the skin depth formula but I would like to design, let said a transformer operating at 500Khz with 6A output, the formula give me a wire AWG 30 (Rac=Rdc) according to...
5. ### Help me with designing a power supply +60/-60 4A

Power supply +60/-60 4A Hi everyone, I would like to design a SMPS +60/-60 4A and I need great help from all of you, I test different approach but without too much succes. I tried the push-pull, the foward converter and etc, but the problem occurs mostly when it come to plug the circuit in the...
6. ### Problem with 400V peak when the transformer in SMPS push-pull is turned on

hi every body, I design a SMPS push-pull the problem is when the transformer is switched a peak appear ... a least 400V, what can I do to avoid that ? change frequency ?
7. ### High speed transformer

Hi everybody, I want to design a high speed transformer, what are the characteristic to consider, inductance, wire size ... I have difficulty to understand the mutual inductance, how do I calculate it ??? My transformer is for Switched mode power supply so it will will run higher than 30 kHz...
8. ### Looking for detailed info about NE572

Hi, does anyone knows the NE572, I would like to understand it more and furthermore make a compressor. I would like to know how to controle the gain stage and how the rectifier work. I also had difficulty to to have a great signal a the out put of my op-amp ... thanks a lot sec
9. ### drop of tension at transistor base

I would like to know, how do we calcul the drop of tension a the transistor base (in common collector circuit) example if I inject 10V in a resistor of 100 Ohm, why at the base the voltage is going to be around 8V ??? is it because of the base resistor (Rin)? please help me, I'm a bit mixte...
10. ### Designing a bandpass elliptic filter

I need help to design elliptic filter !!! I would like to build a bandpass elliptic filter for audio signal. what does a basic circuit look like ? and what are the equations to set the center frequency and to chose the capacitor value ?
11. ### anti feedback circuit for audio application

anti feedback circuit what a circuit need to cancel the feedback, input signal ... but does it need a memory or something like this, does anyone can help me understanding anti feedback circuit thanks !!
12. ### How the Vbe multiplier works in a push-pull amp?

Can someone help me understanding how the Vbe multiplier work in a push-pull amp. And how the value of the resistor are chosen ? thanks !!
13. ### Help me with designing a push-pull amplifier

Hi everybody, I would like to build a push-pull amplifier (minimum 100W) and I miss few thing (almost everything) to achieve my project. I will need a lost of help from all of you. My first question is, mosfet or darlington ? Second, how do I desing the circuit to avoid the...
14. ### I don`t want radio in my circuit

I have made a wah pedal for my guitar, I use a proximity sensor to change the sound. My problem is I receive fm station. Here is the schema of the sensor to resolve this probleme. what sould I do ??
15. ### Phase Shift 10 degree ?

Hi every body, I would like to create an analog latch and I got few questions. This device would act as an normal latch but instead of 0 or 5V output, it would be variating from 0 to 8V dependently of the input signal. I think about a delay and then a comparator(sin, delay) to active the latch...
16. ### References about designing an analog multiplier based on op-amp/transistor

Hi, a would like to make an analog multiplier based on op-amp or/and transistor. Can anyone refer me web pages or help me. thank
17. ### Help me with amplitude comparator project

I wrote a topic but I don't know if it is in the right place please got see it at 70 points reward for the one that help me the most
18. ### Help me with amplitude comparator project

I don't know if the name is right but here is my where I rush. I got 2 sinusoidal signal, on the fisrt one (yellow) it is my oscillator. see TEK008 The seconde one is my antenna (blue). At is normal fonction the signal goes like the (TEK009)picture when somthing is approching the antenna the...
19. ### What are the conditions for a FET to act as a variable resistance?

can anyone explain me the ohmic region in BJT, JFET and MOSFET. I wanna do an active filter with a FET that change the cut-off frequency. I want to know what are the conditions for a FET to act as a variable resistance ? Added after 30 minutes: should I use UNJ to fix this probleme ?
20. ### RF motion detector for humans/animals

Is it possible, by having an emetter and right in front of it (2 meters) a receiver, to detect any kind of human or animal motion ? thank a lot