Questions tagged [power-supply]

An electronic device which supplies electrical energy to a load. Can be AC or DC input. Typically DC output.

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3answers
600 views

Efficient 60v to 12v DC-DC

I'm on the process of building a new version of my ebike electronic systems and I'm searching for a way to lower the voltage of the battery (13s = 54,6v fully charged) to 12v/5v for the accessories ...
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2answers
50 views

What does an U244B IC’s input voltage do?

I’m new to electronics and I’m trying to connect a U244B ic on a breadboard. One pin says it’s an input voltage (pin 7). It works without anything being connected to the input and with battery ...
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2answers
55 views

AGND VS DGND on PCB?

Could someone please tell me the difference between analog ground and digital ground on pcb? It would be easier if you explained it with a example!
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1answer
27 views

Best way to power 2 motors with 1 power supply?

I have 2 identical DC motors rated at 12 volts each. I also have a 12-volt power supply. If I put these in parallel, would the motors draw their required current, or is it limited to the current drawn ...
1
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2answers
161 views

Feeding microcontroller and linear actuators (motors) with the same power supply

I have already made a diagram using a motor controller. The details of the actuators are: Input voltage: 12VDC Max Load: 750N(168.607lbs) Stroke Length: 16 inch Travel Speed: 12mm/s Duty Cyle: 25%. ...
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1answer
36 views

sanity check, current distribution

This is a really basic question I know, I am just doubting myself for some reason. I am trying to make a power distribution board. I have a 12v power supply rated to 20A. If I arrange my DC Jacks in ...
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4answers
145 views

Removing output voltage ripple in high voltage outputs

I am looking to reduce the voltage ripple on a DC/DC converter operating at 5kV. I have looked extensively on the internet and have found multiple ways to reduce output voltage ripple, an ...
6
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2answers
1k views

How does this circuit start up?

I'm trying to understand how CI HT7A6322 starts up. Relevant part of the datasheet says: Control circuit power supply. Also provides a charging current during start up due to a high voltage ...
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1answer
54 views

Suitable substitute for a hard to get IRF440 in a switched power supply?

I am repairing a HP 6023A lab power supply for a friend. The problem was that the power fets had failed. This is what the relevant schematic looks like: The incoming 120VAC or 240VAC is rectified and ...
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0answers
91 views

Using a resistor on one branch of a parallel circuit affects the other branch?

I've wired in one doorbell button to an 18v AC PSU which is working fine, but upon adding a second to the circuit it didn't work properly. I found later that the second type of doorbell needs a '25 ...
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2answers
42 views

Power a 12V Solenoid and a RPi Zero with the Same Wall Socket

I'm building this circuit using an RPi Zero and this 12V solenoid. I would like to be able to power the RPi and the solenoid from the same wall socket using a single power supply. For example, I've ...
0
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2answers
384 views

Running 9v battery in parallel with Power Supply

I am putting a 9v powered circuit into an electric guitar. It will be powered by a 9v power supply through a cable, and also have a backup 9v battery on board the guitar. I am wondering if I could run ...
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0answers
34 views

Powering long-distance sensor bus

I need some help with my project. I'm building an outdoor sensor network with a bus topology. Every sensor node is a 3.3V system which contains an MCU + the sensors + transceiver. For communication, ...
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2answers
609 views

Excessive noise in amplifier circuit when switching from DC power supply to AC-DC adapter

I'm working on breadboarding this amplifier circuit before transferring to a perf board. When we power it from an adjustable DC power supply set to 12V, the audio output sounds clear. When we switch ...
2
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2answers
1k views

Restoring old SR-50 Calculator, odd Charger Voltage

I have an old Texas Instruments pocket calculator, for fun decided to get it working again. It is strictly a NiCd powered calculator, no alkaline recommended. The charger is the 9130, says output 6 ...
6
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1answer
86 views

“Temporary boost” supercap

I have a 12VDC load (up to 10A) that functions correctly down to 8VDC. Sometimes (frequency: many seconds max, many minutes typical) the power source has a very brief (few milliseconds) drop to 7V. ...
3
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1answer
725 views

Generating negative voltage rail using P7805 DC-DC converter

I need to create a negative voltage rail (from positive supply rail), say -5V to keep a P-MOS transistor in ON-state even when the voltage on its [S] source is 0V. So I found this schematic in an ...
15
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8answers
5k views

What is the right way to float a home lab?

I just got myself some new toys for my lab at home like 30V DC power supply, KKmoon signal generator and a Rigol DS1052E. I want to float everything, because I don't want to spend any money on stuff ...
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0answers
27 views

How to select power source for robot actuator with known torque requirement

I am building a robotic actuator that will be backdrivable, this robot will have pretty low RPM. I will be using brushless DC motors. I am trying to figure out requirements for the power source. I ...
0
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1answer
64 views

Overcurrent protection [on hold]

I'm designing a bench power supply using Arduino with some sensors and modules, for overcurrent protection i was thinking to add a relay to cut the output when it hits the current limit. but relays ...
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0answers
37 views

How to turn off a stove using a diy in-circuit timer? [on hold]

I cooked for decades exclusively with a microwave, and it's main feature is that I can set it and forget it. I am now using a two-plate stove and can't ignore it. But I do. And it has burnt many ...
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3answers
561 views

Single Supply in Op-amps

I am using in a project TL081 operational amplifiers and an INA118P instrumentation amplifier. Both need a ± 15 V Symmetric Power Supply, however I have seen some projects in which it uses single ...
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3answers
478 views

How would you detect vampire/standby power?

Is it possible to detect when a device is consuming power in a stand-by or nominally off state? For example if I leave my charger plugged in, detect that a small amount of current is being drawn and ...
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0answers
10 views

Build 9V powerbank from a generic USB-C PD (or QC3) powerbank [duplicate]

I need to use a powerbank with device with these requirements: 9V, 500ma. New USB-C with PD feature can deliver higher voltages than standard 5V and 9V (upt to 2A) is one of these. As far as I know ...
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1answer
39 views

Touch IC TTP223 is hanged at 5V after some times work

I used TTP223 IC which is operated at 5V , i use touch ic output(When High)to turn on the led and (When low) to dim the led. LED is operated by the External 5V and used only touch ic output as signal ,...
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1answer
92 views

How does such an USB step-up 5V-12V work? [on hold]

I just bought a cheap USB 5V to 12V step up converter: Surprisingly, it works very well. There is few place for electronic components (maybe in the USB connector?), how can we do a 5V to 12V ...
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1answer
59 views

Circuit with dual power supply

Doing some reverse engineering to a PCB, I drew this part of the circuit. Looking into the datasheets, I found out the comparator (LMC6772) is able to drive the SCR (S6S2) by itself. But the designer ...
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1answer
58 views

How to draw ~1A from Li batteries without damaging/over-stressing them?

I have designed a micropump driver powered by 2x AA (Li) batteries, the pump is piezoelectric and requires 27V. The pump requires a switching waveform, at the battery side this draws (including ...
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0answers
31 views

How turbocharger mobile charger works?

I have found a turbocharger from a motorola device which has 5V, 9V and 12V outputs. I want to use this charger to run raspberry pi 4. I need to know how tutbocharger changes the voltage? I am scared ...
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0answers
11 views

How to power a ln R-Pi? [closed]

I bought a R-Pi some days ago. We all know raspberry pi needs 5V 3Amp to operate. I have these options for the power source: I have an SMPS (Detached from a Desktop PC) which have 5 V and 15 Amp ...
0
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1answer
53 views

How can I power a 3.3v circuit with a 9V power supply and two AA batteries?

I have a circuit that runs on 3.3v. I want it to be able to operate on two AA batteries down to about 2.2v (or until batteries are dead), and also with a 9V power supply. When the power supply is ...
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2answers
408 views

MC34063 with external FET. Why?

Follow on from : earlier post Below is an LTSpice simulation of an MC34063 step up (5v to 9v) circuit. As you can see, this particular circuit is working correctly, and delivering about 300mA. The N-...
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0answers
39 views

low power high efficient unregulated ac/dc converter

I am needing to graph an ac voltage onto a computer screen. The voltage is proportional to the moisture content of soil. The ac voltage is close to 0 when the soil is extremely dry and around 100 vac ...
0
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2answers
83 views

Power supply circuit capacitor selection

I'm planing to use this circuit for my op amp test but I don't understand capacitor selection Why C1 and C2 selected 2200 uF but C3 and C4 selected 1000 uF? (C3 is 1000 uF picture is wrong) I tried ...
0
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1answer
55 views

Is isolation required for MOSfet gate driver's and microprocessor's power supply?

I have designed a 62W , 24V-5V buck converter operating at 250KHz. I am using TI's UCC27200A gate driver and Infineon's Optimos 4. The problem is that the driver doesn't have any kind of isolation ...
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1answer
48 views

Creating a 5 volt (ish) power pack from 18650 batteries

I want to create 5V power supply for a portable lighting project, using 18650 batteries. The power supply needs to provide power to an arduino (which can take 3.3V to 13V input) and some addressable ...
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0answers
45 views

Can a power supply breaks in this way? [closed]

in the last month the power supply of the same machine breaks 3 times. I wonder if it is possible that the machine itself is breaking them. The technician told me it’s impossible because the power ...
0
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1answer
155 views

5 volt power supply directly from 120 volt

I would like to use a microcontroller to drive a TRIAC (Z0103MA0,412). The TRIAC will be switching a 120 volt a/c resistive load. I would like to derive a 3 volt or 5 volt CD power supply directly ...
2
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0answers
139 views

How do airplane in-seat power detection circuits work?

Airplane in-seat AC line-voltage power outlets have limited available current/power. I remember reading that laptops or laptop power adapters can somehow detect this and inform the laptop that it ...
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0answers
58 views

which component in this power supply results in the generation of -VCC (-12 volt)? [closed]

This power supply board has 3 output voltage pins.....but it is not mentioned on the board what the output voltage is of this power supply....The 1st pin is +VCC ; 2nd pin is GND and the 3rd pin is -...
2
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2answers
84 views

PSU drops both current and voltage when connecting to an LED

I'm connecting a DC PSU to a high power LED. I'm setting the maximal current, and a voltage. For the first few seconds, I'm in the c.c mode (voltage drops from its initial value to a lower one). But ...
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0answers
8 views

EP53F8QI Short to GND fault

We have a design with an EP53F8QI that multiple ICs have been burned both at room temperature and +80 °.C. We are using it to create a +3.3V and on fault we have found that the +3.3V supply is shorted ...
1
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1answer
98 views

Mechanical Switch Causes Transients from AC-DC Power Supply

I'm having trouble getting rid of output transients from this Mean Well PSU right after the AC input is switched. https://www.meanwell.com/Upload/PDF/RPS-500/RPS-500-SPEC.PDF The PSU is a RPS-500 ...
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1answer
71 views

Connecting and disconnecting the power supply

I have learned that powering a chip without ground is quite dangerous and might cause permanent damage to the chip or the board in general. I have also seen that happening many times in non isolated ...
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2answers
108 views

Why don't people power LED strips in parallel instead of using amplifiers?

The common pattern to run long LED strips seems to use separate transformers and amplifiers in between the individual strips. Why not use a single transformer, controller and appropriately thick ...
31
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3answers
14k views

How can I detect a power outage with a microcontroller?

I have the following power supply configuration: AC MAINS -> UPS -> 24V POWER SUPPLY -> 5V VOLTAGE REGULATOR -> PCB (microcontroller). What's the best solution to detect the power outage on the mains ...
0
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2answers
414 views

Transient Power Supply with LM317 and LM2576

I have a power supply to power up a 8W LED board and a raspberry pi. I have used a 24VAC (12-0-12V) 2A transformer to feed the bridge. I have also used a LM317 to provide a voltage of approx. 15.8V ...
0
votes
1answer
24 views

Tp4056 Module 12V input

I want to build a lithium ion battery charger with tp4056 module but most of my power supply's voltage is 12-19 V Datasheet says input voltage is 4.5-5.5v and current 1A Can I connect 1-3 tp4056 ...
0
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3answers
132 views

LM723 based bipolar power supply solution question

Why TL081 and 2N3906 may get very hot? The simulation of the TL081/2N3906 shows the normal working temperature, but I measure +62 ºC
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1answer
60 views

Rf Quiet variable power supply from switch mode?

Is there a circuit diagram somewhere for turning an ATX switch mode power supply, or one of those cheap switch mode psus on eBay, into a variable and RF quiet power supply? I’m assuming it is ...