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  1. A

    Uc3825a based smps trouble

    Hello I am trying to repair a smps power supply based on UC3825A Problem is the resistor R49 & R34 get burst as soon as i start the smps I am not able to find out the issue SYS_ECON is a 0-5v given from MCU desired by user to control 0-180v smps output
  2. Anditechnovire

    Battery charging

    Please I have some couple of 3.6v 3Ah cylindrical li-ion battery, but since I bought them, charging it became a huge problem. I first connected a single one to a 2A infinix phone charger (made in china. According to the ratings, it capable of adjusting output current and voltage to load)thinking...
  3. Anditechnovire

    Switching power supplies

    Please am studying about switching power supplies, starting from the simple ones. I've just concluded on joule thief and blocking oscillator, now am progressing to Self oscillating flyback converter(or RCC) and am finding a bit difficulty on how the transistor switches OFF. It seems the...
  4. E

    Help in identifying component

    I am repairing a power supply. Please I need help in identifying the white color cylindrical component. It is labelled T1 on the PCB.
  5. S

    Synchronous Buck Converter with Negative Feedback Loop

    Hello, I am in the midst of creating a synchronous buck converter. The requirements of the converter is the following: Vin = 30V - 50V Vout= 3V - 5.5V Io >=12 A Now the power stage works perfectly with ideal as well as realistic components. After investigating that the power stage works, I...
  6. sr13579

    SMPS is bouncing while connected with Peltier Cooler

    I have a peltier cooler TEC1-12706. I used an SMPS which can give 12 Volt and 20 Ampere. While I am connecting the peltier and cooling fan(Parallel) the cooling fan is bouncing along with the smps(It seems like smps is restarting). I assume people will say the smps is damaged. But it is working...
  7. Shadow_warrior

    Ripple in output voltage

    I am working on an Active Clamp Forward converter. Schematic is given here: Specs: Output voltage-5V Input voltage 26..42V frequency=500KHz Output power=10W It is working fine in open loop, but in closed loop I am getting a ripple in output Voltage of 2.5Volts Peak to peak. Voltage...
  8. polashd

    Effect of change in frequency or duty % on transformer output

    In case of a smps transformer of 1:2 primary and secondary turn ratio roughly the output voltage will be double & current will be half of input. My questions are what effect will be on output, if 1) Frequency increase or decrease (when duty % is constant) 2) duty % increase or...
  9. S

    Need help Bose Soundtouch 30 smps switches off when tweeter speaker connected.

    I am trying to repair a Bose Soundtouch whose smps shuts down. Unfortunately I do not have a circuit diagram and Bose do not provide one. This set has two ic's, TDA3100d2 to power the tweeters and TDF8599B to power the woofer, both of which are getting power (24 volts) from the same smps...
  10. R


    hello guys , Here is the situation, I am working on a 90 watts , 1050 mA , 72 V flyback based constant current smps which is used for outdoor LED lights, Mosfet used 12A 800V O/P diode used - Average forward current 8 A , Peak revers voltage 400V In this design diode and Mosfet are getting...
  11. F

    driving motor and simulation

    Hi, I work as inverter and dc / dc designer, but I'm new in three-phase motors' subject. I should make a project sketched in the figure. the characteristics of the motors are in the picture. I say the pilot will be in open loop. how are the discrete components (MOS or igbt) dimensioned in...
  12. T

    Frequency of high voltage diode

    Hi I want to buy 2CL2FM . http://www.hvgtsemi.com/upfile/pdf/2012110817253555456.pdf Trr =100 ns I want to find out the real switching frequency of the diode. Can I apply it in the smps with 100 khz of switching frequency? Regards
  13. B

    Power supply design in automotive for 12V and 48V battery system

    Hello all , I wish to design a switch mode power supply , dc-dc buck-boost converter, ('with Vin - from 12V to 48V ) and Vout from 2V to 20V with Iout - upto 6A, There are many IC's available from Ltspice and Texas Instruments. I have design the block diagram , but I am not sure what should be...
  14. learning

    SMPS Power Supply for LA 4440 IC

    Are this Chinese made SMPS power supply compatible with LA 4440 IC? I mean that can I use it for any audio amplifier or Bluetooth mp3 FM module? Please tell me! If I can use it, then please tell me how I can do it?
  15. E

    Vizio m65-c1 Power supply board

    Having a problem finding the problem on the power supply board. The board turns on and off in a 2 hz pattern. Checked the input capacitors and they are all good and never drain even after remove the input supply. Tested all the mosfets and they check out good. Checked the opto isolators and...
  16. E

    Help with my simple SMPS design

    Hello, I have a little problem. I chose a project for school which I've managed to get working... All the circuitry before and after the SMPS is working properly, my only concern here is, that the SMPS is only working at an efficiency of around 54%. I've added my schematics for the SMPS...
  17. L

    SMPS: Substituting SBD/Power Diodes 1A for 1.5A and Filter Cap for +20% safe?

    This is my first post :) I'm not going to be begging for help to be babied all the way. I did Dick Smith Fun-way electronics kits (Australia) as a kid, but when you are working with mains you have to be very careful making the smallest changes to a circuit design. Hence I'm asking for a few...
  18. Ragooman

    Rusty on Noise problems from SMPS

    I'm a little rusty on noise problems from switching power supplies. And I hope someone can offer some advice. There's this new system which relies on a small +12v smps. This system has a separate controller board mated with a motor controller using board connectors. And the 12v smps connects...
  19. riccardo

    AC-DC PSU 15V, 2A - Where to buy a compact module?

    Hi, Does anyone know of something to convert 240V mains to 15V DC at upto 2A? I want it to be as compact as possible. I've been looking for PCB mounted modules but the price and size of them seems ridiculous. For example; Farnell sell a VTX-214-030-115 for £20. You can buy a whole bench PSU...

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