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

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1answer
19 views

How can I make an uninterrupted switch from battery to fixed power for a mobile computer?

I have a computer being powered off a Lipo battery, and I would like the ability to transfer the power supply from the Lipo to a fixed DC source (eg. power supply) without having to turn it off and ...
0
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1answer
46 views

bypass a low voltage shut off [on hold]

Is there a way to disconnect or bypass a low voltage shutdown operation? I have a factory made electronic shooting gallery (toy) that runs on 4 AA batteries. I want to run it to a steady 6VDC supply ...
0
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1answer
36 views

Using a multi tap transformer

I'm new to electronics I have need some help with a power supply design I am designing. I currently have a 0-30 volt, 2 amp multi tap transformer that I am using for the above mentioned power supply ...
0
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1answer
38 views

USB power/battery source switch

I'm building a circuit to switch between a USB 5V source and a battery source that ranges from 2V - 3.3V. The rest of the circuit runs on 2V - 3.3V so the USB 5V source is passed through an LDO before ...
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2answers
52 views

Stepping down 12VDC linear power supply to 9VDC

I have a +/-12VDC power supply that I have built up for testing simple audio circuits. It works just fine for me now but I would like to add a permanent +9VDC leg to it. I have never seen a scenario ...
0
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0answers
57 views

How to come up with -5v DC & -12v DC for ATX PSU [on hold]

This maybe a known answer to many but this is the first time I have ran into an issue where i needed to make a -5vdc / -12vdc connection. I am speaking of the ATX power supply connections: Notice ...
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1answer
53 views

125 ma slow blow fuse glow

i have been troubleshooting a guitar amp that blows the 125 ma slo blow fuse upon startup. The fuse does not blow when the amp is brought up to 115 VAC with the Variac. However when starting the amp ...
0
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1answer
44 views

Triple Step-Up Power Supply

I need 5V, 12V, and 30V power supplies for an RF front end tuner. I'd like to power them with a single AC adapter, either 12 or 18V. Obviously it needs to be pretty clean to function with RF. The ...
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1answer
38 views

Transformerless power Supply - 24VDC, 120V AC and 230V AC

I want to know if it is possible to design a power supply for a circuit that can operate from DC and AC using the same input terminals. Thus, the output should be xxV DC (5-24 or whatever is decided ...
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0answers
64 views

Electrical Outlets changed from Outside adjacent to inside plugs [on hold]

This is the second time I have dealt with WiFi being hacked and electrical plug issues. Moved to new home. Recently noticed red lines drawn on ground directly below several different elec. outlets. My ...
0
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1answer
32 views

What is the name of contractors designing high power supplies with relay logic? [on hold]

I have been designing a 3 phase power supply with distribution strip and redundant contactors with failure detection (I posted a question not long ago related to that, it's based on relay logic), and ...
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0answers
37 views

What circuit is used to power up a 3W LED light

What circuit should I use to power up a 3W common anode RGB LED direct from mains (220V)? I am working on a 3W rgb led which has 3 diodes connected in parallel with their + terminal as common anode. ...
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2answers
45 views

Metal Halide Bulb with Instant On?

Is it possible to produce/obtain a metal halide (MH) bulb with the possibility to turn it off and on instantly - again and again? Most MH products require 30+ minutes to restrike.. Why is this? ...
0
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1answer
36 views

Power for 24VDC 5A Motor

I have a 24 VDC 5A motor. I wish to power it with two 12V motorcycle batteries in series for about one hour. Can I hook the batteries up directly or will I fry the motor? Does the CCA of the batteries ...
0
votes
1answer
30 views

no-load DC output voltage of DC wall-wart circuit

I have this question and I believe the answer is 12.73 from the equation V(N) = V(Rated) * sqrt(2). Is this the correct formula and can someone show me how we arrive at it if it is. I am unsure ...
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2answers
35 views

Latching switch turning back to off on power loss

I can't twist my head around the proper use of my latching switch problem. In detail, the latching (or maintained) switch should switch a 48V DC source power supply for a cisco router. The 48VDC power ...
0
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1answer
33 views

SIM800L power interface

I would like to use SIM800L for M2M. I have power of 5V 2A for powering uC board and would like to add gsm module. It seems that SIM800L has rather strange voltage input rating: 3.4V - 4.4V. What ...
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0answers
22 views

difference between a linear power supply and linear CONTROLLABLE power supply

Since i am new to power electronics (practical) stuff i just want to make sure that my understanding of "difference between a linear power supply (AC->DC) and linear CONTROLLABLE power supply ...
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1answer
70 views

Charging capacitor with higher voltage power supply

I have a maxwell 1200F 2.7V ultracapacitor which I charge using a 16V supply and a voltage divider in parallel with the capacitor. It's a really slow charge. I also have a 4V supply which has higher ...
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0answers
12 views

Reprogrammable Remote Power Supply Raspberry Pi Monitor and Control

I currently have a reprogrammable power supply (HCS-3400) hooked up to be controlled remotely from an control/monitor app provided by the power supply company, Manson. The supply is connected via USB ...
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0answers
41 views

high voltage power amplifier [closed]

I am trying to find a power amplifier which can amplify 24V car battery to as high as 3000V for a short period of time (can reach 3000W or more). Is there any product on market? Or anyone has a design ...
1
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1answer
44 views

What type/topology of SMPS is this?

I'm researching designs for a simple bipolar output switching power supply and came across the design below in a ST datasheet for the MC34063A. However, there isn't enough information in the ...
0
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1answer
39 views

How to wire a RCBO/GFCI correctly (in series with the upstream RCBO/GFCI)?

For one of my projects, I need to add a RCBO/GFCI for the protection of the users. I know that there is a RCBO somewhere up the chain, therefore I am facing a confusion: there is a non-zero resistance ...
0
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1answer
72 views

Floating vs Grounded Source, and Decoupling Capacitors

I am confused about the following: in my lab, we all run electromagnets off of pretty beefy power supplies. Everyone else grounds their supply. Mine is floating. I do not have even a remotely good ...
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0answers
47 views

MC34063 issue. Switches off every cycle

I am using MC34063 in step down configuration but the converter switches off every cycle. Following are the calculations and specifications: Vin - 9 to 12V Vout - 5V Imax - 0.3A Rsc - 0.36 ohms L - ...
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2answers
97 views

Practicality of this LM317T PWM Voltage and Current control circuit

Ive been trying to design a LM317T power supply with a PWM (Arduino MCU etc) adjustable voltage and current limit. After various circuits, videos and tutorials i have designed the following circuit in ...
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2answers
65 views

reducing mechanical vibration from a PSU

I have a keyboard synthesizer which emits a 60Hz hum due to mechanical vibration of its PSU. The vibration is magnified by the metal chassis of the synth which acts as a soundboard. It’s very annoying ...
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1answer
65 views

Why do wall plug power supplies use audible switching frequencies?

Every plug-in power supply ("wall wart") I have ever used starts off silent, but eventually starts to emit high frequency switching noise. It usually happens only when the charger is on, but not ...
1
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1answer
51 views

Pin of micro USB connector in Smartphone

The image below shows a Micro USB connector in a smartphone. I understand what the first 5 pins of the USB are i.e. USB_DM, USB_DP, USB_ID , VBUS and GND. The pin S1 is connected to VBAT (battery ...
0
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1answer
39 views

Switching and protecting batteries from external power supplies

my device can work from external power source as well as from two AA batteries, so voltage in this case is 3V, but external supply is 5v. I need to protect my circuit and power supplies in case of ...
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votes
1answer
55 views

AC-DC Adaptor flashes on & off

i have bought an ac-dc adaptor to power my mini-water pump. When i give power to the pump it start & goes off immediately and it's repeating like that till i plug it off. Adaptors LED is also ...
1
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1answer
49 views

Significance of Vf terminal in Li-Ion Battery

i was going through some propriety schematics that i can't post the battery used in the schematic is a li-ion battery of 3.8V/2.1Ah/ from samsung, which gives out three pins ...
0
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2answers
55 views

Can I safely substitute a DC converter for the Macbook's AC adapter?

I want to go from this: to this: The converter would be this: http://smile.amazon.com/dp/B00HVCWGNE or something like it. Does this sound safe? The step up converter would be set to a specific ...
2
votes
3answers
136 views

CR1632 (3v) vs. Two AA's

Kind of a newbie at this, so forgive me if this is a stupid question. I've disassembled a small lifeline alert pendant transmitter that normally runs on a CR1632, can I replace it with two AA's? Are ...
0
votes
1answer
38 views

Looking for confirmation on power supply project

First time poster - this site's been really helpful for me, so thanks to all of you. I'm working on my first electronics project not from a kit, and am attempting to make a variable power supply. I'm ...
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0answers
42 views

led light engine design

i want to know -How to connect the led in series and in parallel according to the given watt? if we have:-7watt-170ma current,45volt,current tollerence-160 ma we have led of:- (1) 0.2watt (2)0.5watt ...
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2answers
72 views

How to detect a plug is connected to socket

I have a plug and socket. Before I turn on power supply from a contactor, I need to detect if the plug is connected to the socket via a microcontroller. Any ideas on how to do this ? UPDATE: The Plug ...
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votes
2answers
53 views

how to calculate the capacitance for variable power supply 0-20v

I am trying to make a variable power supply of 0-20 V; as we all know it uses a step down transformer, bridge circuit, then capacitors and LM317 regulator But I want to know how the value of ...
0
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0answers
67 views

Simplest way to switch between power sources?

As I mentioned in another question, I have a battery charging setup where currently AC power feeds a AC-to-DC power supply which outputs 48VDC to a battery charger. The limis for the charger are: ...
1
vote
1answer
39 views

Valve heater voltage without separate windings

I want to build a simple single-ended valve amplifier from an old TV. I am facing a problem, that I don't know how to produce the 13V, 300mA supply for the heater.(PCL86) I am using the mains ...
2
votes
5answers
104 views

Superimpose a data transmission on a custom AC voltage line

I hope this question is valid for this forum. I’m not looking for you to give me a working solution, my question is of the nature where I can find literature, other learning resources, which search ...
1
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1answer
52 views

What is a full rectangular output characteristic for a power supply?

From what I understand, a rectangular output characteristic of a power supply refers to the fact that the maximum power is achieved when Vmax and Imax occur simultaneously. Kepco has a power supply ...
1
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1answer
33 views

Enable connected to unpowered regulator on another board

I have an ARM board which uses a VIO of 1.8V and requires that no i/o line be driven before it is fully powered up. It signals this readiness by asserting its "SYSEN" line. My design has SYSEN from ...
0
votes
2answers
60 views

How does single supply transimpedance opamp circuit works

Was going through this webpage and noticed that a trans-impedance amplifier using single supply. However, I am unable to understand how it would work? How would the opamp see inverting ...
1
vote
3answers
97 views

How to automatically switch to backup power? [closed]

To solve the frequent power outages that happen where I live I ended up using a spare car battery I had and a power inverter (one of these). With that I have more that an hour of backup power so it's ...
3
votes
2answers
377 views

Is it safe to implement a split power supply from two identical AC/DC adapters? [duplicate]

If I have two identical AC/DC adapters(Such as laptop adapters) can I achieve this as in the following illustration? Would it be safe?:
1
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1answer
104 views

Is there an IC to make a split power supply from a single power supply? [duplicate]

I'm trying to find the easy but a somewhat stable way to create a split power rails Vcc Vee for the opAmp applications. Any specific known IC for this purpose?
0
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0answers
36 views

separate power supplies risks, is there a difference between USB and SATA?

I would like to confirm that, if you have external powered USB and SATA devices that there is a difference regarding risks to connect them to a computer. As I understand it, in the case of USB, ...
0
votes
1answer
40 views

Supply voltage of LM741 with Virtual Ground

I'm looking for a way to feed LM741 with a battery. I found this example that uses the TLE2425 to create a virtual ground of 2.5V (in the original example was used opamp TLC272): I simulated this ...
1
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1answer
177 views

Use indepenent power sources for Arduino and for breadboard

I am building a breadboard circuit to be controlled by Arduino. The circuit consists of about 20 bright leds simulating a vehicular lighting system (ten leds for headlight, 4 in taillight, 3 for each ...