power adapter

  1. somdutttah

    Need help with Power Adaptor voltage

    I have a 12v rated adaptor but the output voltage it is giving is 13.7v which is very high to charge a 12.6v 3s lithium battery pack. So need help to understand this circuit and how to make this circuit produce 12.6v
  2. darrenrahnemoon

    Designing an Inverting Boost-Buck Convertor Issue

    Howdy! I'm trying to design a boost buck convertor from a 3D printer power module and I am using Multisim to simulate it before starting but I think I'm having issues with the biasing. (EE student noob here so bear with me!) My requirements are Vin 12V-30A Vout 0-50V (inverted) For the PWM I...
  3. D

    Power diagram? (looking for a power supply for this)

    Guys I’m just starting off and I need to find a power supply replacement for this device.. I’m confused as to what this diagram is saying it’s not an input and output , it’s a non static power supply ? What exactly is it saying trying to find the power supply box that will work with it …
  4. S

    5V to 1.5V voltage conversion

    Hi, I am trying to replace a battery powered circuit with a AC to DC adaptor circuit. I have a 5V adaptor but the device requirement is 1.5V. So, what is best way to reduce this voltage? Is using a resistor good enough? If so can you help me in understanding how to choose the value of resistor...
  5. Maurooo

    Help for connection of lithium battery with Heating Pad (Newbie)

    Hello everyone I am working on a project in which I have to connect a 12v resistor (Polyimide Heater) with 150 watts of power to a manufactured lithium battery. The battery is 12v and 17600 mah (with a BMS 3s 20a module). (Reference images) So the idea is to be able to connect and disconnect...
  6. D

    What type of AC power cord connection is this?

    My kids lost the power plug that goes from the wall outlet to the AC-DC transformer shown below for a video display. Can anyone tell me the name of this style of V-shaped female connector so I can order a replacement? I have searched a bit online and can't find this particular style.
  7. P

    Step up 5vdc to 72 volt ac/dc

    1. I use a medical therapy device that needs 72 volt ac input. 2. Need to drive the medical device from a 5 volt dc Powerbank for mobiles that are readily available in markets 3. For that, I need to somehow step up the powerbank output from 5vdc to 72volt (either ac or dc) 4. The max load...
  8. C

    AC-DC Power supply failure

    The attached image is my failed 120VAC 1.0A -> 30VDC 0.5A power supply. I'm trying to figure out what I need to change to fix it without changing everything. I'm not an electronics expert, but looking at the board it has a transformer, one big capacitor and two smaller ones, a transistor...
  9. B

    What does these two block in mppt represent?

    from the mppt, these two blocks (1; 2 mppt figure) what their function according to the code (DutyRatio https://paste.debian.net/1225049 ) ? mppt figure :
  10. A

    How to chose power adaptor

    I am having 12v power jack on the board, which inner dia 2mm and outer dia 5.5mm...now I need to chose adapter for this jack...what should I take care..what should be ideal plug dia of the adaptor? I am using PJ-102A part. Thanks Ash
  11. MrsssSu

    Will voltage across transformer drop when charge a lithium ion battery?

    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...
  12. MrsssSu

    Convert triangle wave to sine wave.

    Hi readers, the IN node has triangular wave converted from square wave pulse. This Op-Amp acts as integrator. However, when I attach the same integrator circuit to convert this triangular wave (IN) to sine wave, the Output (OUT) I got is still quite triangular and not quite a good sine wave...
  13. MrsssSu

    Amplify Flip Flop signal from NE 555 timer using transistors

    Above is the graph across R7 (Load). Hi readers, Flip Flop with Ne555 timer means turning on an led and another one off, as shown in picture, and this alternate on and off pattern continues. This video can be found at Click Here . I have succeeded in amplifying one of the 2 signal as shown in...
  14. MrsssSu

    How Power Supply Limit its Current Output ?

    To view my We_bench power supply schematic Click here In the picture above, how does the power supply limit its max current and it has been fascinating for me to figure out how. Does anyone have a clue on this? I just know that the capacitor and diode help to rectify the AC output of...
  15. MrsssSu

    20V max DC motor, how do hairdryer work on cool air without heating filament ?

    Hi readers, Hairdryers (240V AC) actually works on a design which current passes through the heating filament (Maybe consume 220V) to produce a lot of heat whereas through the DC motor (Maybe consume 20V). I have always been curious about this Question: Hair dryer has an option of choosing the...
  16. MrsssSu

    Charging circuit modifications

    Hi. above is a charging cut-off circuit. As you can see in my demo. when voltage source is 5V, the load (R9) has 5W power. When voltage drops to 4V, the load (R9) has 0 W (cut off). However, my lithium ion charging pin for my battery is 4.26V. Thus, when battery fully charged at 4.2V, the...
  17. Jorne

    AC adapter broken after repairing cable [solved]

    Hello, I had an old AC adapter (230V AC to 14V DC). There was a small part where the insulation of the cable was damaged. You could see the copper coming through. So, I cut the damaged part away, soldered the wires back together, and insulated them with heat shrinks. However, when I then tested...
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