Questions regarding the safe and effecient design and implementation of AC voltage to DC voltage supplies. Typically Mains to some lower DC voltage.

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0
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2answers
246 views

Multimeter reading 0 and drawing too much from DC power supply

So I've got a circuit that requires both 5V and 3.3V so I bought a 5V 2A AC/DC converter from a store, which I will add resistors to later for the 3.3V. Before I connect it to my circuit, I wanted to ...
0
votes
0answers
19 views

120V ac to normally open alarm signal

I need to monitor the status of our commercial AC supply and the status of our two diesel generators, for this I need to generate three alarm points that will go into our building alarm system as ...
-1
votes
4answers
193 views

How to convert 700V AC to 5V DC 500mA?

I have a device that requires approximately 500 mA at 5 VDC, and I am required to get this power from two legs of a three phase power supply. The voltage between these legs can be between 110 and 700 ...
2
votes
2answers
58 views

What are the safety and device risks associated with not connecting the grounding prong on a 120V AC device?

For example, imagine a device that comes with a 3-prong (grounded) AC plug. What are the risks associated with, for example, plugging this device into a 2-prong extension cord which effectively ...
1
vote
2answers
121 views

What are design considerations for grounding an enclosed AC-to-DC converter?

Here I'm talking about a device that takes 100-240V AC in, and outputs 10-20V DC out. In terms of grounding, I'm referring to the grounding offered by a standard outlet (e.g., a NEMA-5-15R receptacle)....
1
vote
2answers
75 views

Can I use a Triac dimmer circuit to control the brightness of an AC powered LED light strip? [closed]

I am using this Triac circuit to control the brightness of several incandescent lights. The circuit monitors the phase of the 120 volt wall current, then signals an Arduino when the phase crossed ...
0
votes
0answers
19 views

LNK306 based +/- 3.3V AC-DC power supply does not work right

I've been trying to design a power supply using PI's LNK306 using the datasheet and this application note. On page 10, the app note lists how you can create a +/- rail for the power supply. The note ...
0
votes
1answer
38 views

DC-LVDT Output noise filtering

I am working with the DC-LVDT Omega 620-25 http://www.omega.com/pptst/LD620.html Manual: http://www.omega.com/Manuals/manualpdf/M4345.pdf Specs: http://www.omega.com/pressure/pdf/LD620.pdf I am ...
1
vote
2answers
83 views

Is a capacitive power supply safe?

I'm doing a home automation system which uses a RF transceiver(nRF24L01+) paired with an arduino to control the relays. Since these require low power DC to run I was researching on ac to dc when I ...
0
votes
0answers
31 views

LNK304 noise comes when using it's output

I've built a power converter with LNK304 for 230VAC to 5VDC. The schematic I've used is in the datasheet: http://www.mouser.com/ds/2/328/lnk302_304-306-179954.pdf at page 4, figure 5. First of all, ...
0
votes
3answers
36 views

Using thermal overload protection in AC-DC PWM motor driver circut

i'm having some difficulties with calculating the value of the thermal overload fuse in this circuit. The thermal fuse is used to protect the motor and the circuit behind it. The deal problem is that ...
0
votes
2answers
93 views

Isolated AC/DC Buck Converter

Why are there no isolated AC/DC buck converters around? For applications < 10W (say 5V/1A output) and mains input (85 - 264VC), is it feasible to use a standard buck circuit but add a 1:1 ...
1
vote
0answers
84 views

12VAC to 12VDC Converter Requirements for RGB LED Controller

I have an outdoor lighting transformer (operating at the usual 12VAC) that I want to add a strip of LED lights in a new run. The transformer has two legs, each ...
1
vote
2answers
300 views

Purpose of capacitor across transformer in AC-DC power supply? [duplicate]

I have been looking to buy a AC-DC 5v power supply module to power a mains relay in a circuit I am making. I came across a couple of different models on eBay and am trying to understand their basic ...
0
votes
2answers
90 views

AC Adapter gives much more voltage than it's supposed to [duplicate]

Hello! I have this one older AC-DC adapter from Korg (wallwart?)... ...that I have been using for my (guitar) effect pedals for a few years, and I recently found out (when I was doing some ...
0
votes
1answer
59 views

Use 5w/3w 12vdc LED on 60w 12vac cdi ignition

I'm building a vintage two stroke race bike out of a 78' puch maxi. The original points setup is junk and I'm switching to a CDI. I have an LED headlight that I'd love to use for aesthetic purposes. ...
-2
votes
1answer
64 views

Connecting two DC voltage sources in series

I need a 42 volt DC supply to check a motor. All I have is one 30V DC source and a few rated lower than this. Is it possible for me to connect the 30V source and a 12V source in series to get the ...
1
vote
1answer
59 views

Power adapter efficiency standards, any drawbacks?

Supposedly, some new federal regulation is imposing "energy efficiency" standards on small power adapters. How is this going to affect electronics? Are the old types of adapters going away? If so, ...
2
votes
1answer
42 views

Battery charger output power higher than input?

i would like to ask about battery charger i saw at work :) the plate on charger says: Input voltage 3 phase ac Min 400v Nominal 400-415v Max 456v Input current 20A Output 110v DC 9kW 28v ...
0
votes
3answers
347 views

220 AC to 220 DC Converter

I am designing a circuit that will give me an adjustable 220DC voltage. The load is approximately 2kohms, so the maximum current that will flow is 100mA.And I have design restrictions, it needs to be ...
0
votes
4answers
109 views

Oscilloscope and main earth reference

I have AC/DC 3/6/12V out universal adapter with two pins (without earth connector) and would like to use it for powering my arduino project and playing with oscilloscope. Knowing that my oscilloscope ...
0
votes
3answers
172 views

Need to build a compact power supply that runs off the 240V socket and provides 12V, 5V and 3.3V for an Arduino Project [closed]

I want to have an as-compact-as-possible (but no limit on size) power brick/supply that takes power from a UK Wall socket and has multiple outputs with different voltages. Need 12V@2A for stepper ...
0
votes
1answer
67 views

input current vs output current

My old/new laptop adapter specs as given below. I understand the output current for new is 4.5A which is OK when compared to old which provides 3.25A load since it can provide more load. However, ...
0
votes
1answer
57 views

Using AC-DC converter Module

I am trying to use an AC/DC converter module developed by third party. In the data sheet, I see following Is there any way I can do both at the same time?
1
vote
1answer
119 views

Why there are AC timing characteristics but not DC in I2C interfaced chip?

I'm quite newbie in electronics, and I'd like to learn why there are AC timing characteristics to this particular EEPROM (24LC512) that I'm using but none for DC? Does AC timing constraints apply to ...
0
votes
1answer
91 views

2 AC to DC converters in series problem

Hello, I am a beginner at electronics. I have two AC to DC converters ((3),(5) in image). The converter with the number 3 is connected parallel with my room's light bulb. It converts 220v AC to 12V DC ...
0
votes
2answers
166 views

Is there a reason why some ac/dc adapters don't have a grounding pin?

I'm searching for an AC/DC adapter of 6v 300mA, but I can't find one with a grounding pin (E-type). Is there a specific reason for this?
0
votes
3answers
176 views

link voltage and link capacitor basics [closed]

I am currently getting into the topic of electric vehicles and I often come across the terms link voltage and link capacitor. simulate this circuit – Schematic created using CircuitLab ...
-3
votes
1answer
71 views

Computer Power Adapter Proper Volts No Amps [closed]

I have a 4 month old laptop. The other day it stopped charging. When I meter it shows 19.94 volts and 0.0 amps. Specs call for 19.5 volts and 2.31 amps. So the manufacturer (HP) is sending me a new ...
0
votes
2answers
350 views

How to plan my LED circuit, voltage, and resistor

The LED emitters in my outdoor lamps blew out and I need to replace them but I have to rebuild the emitter from scratch because replacement parts are not available. The whole lamp was made in China. ...
5
votes
2answers
918 views

Why are PCB-mount AC DC converters so expensive? [closed]

In a thrown-together prototype, I used a few wall warts to get the various voltages I needed. Now, I'm trying to build a cleaner version with a single plug and put it all on a PCB to eliminate my rats ...
1
vote
1answer
147 views

Need help with stepping down DC volts

I don't have much experience with electronics, I'm simply trying to get (at least what I think) is a fairly simple circuit running. I've got a blower fan that I need to get running. It uses 12VDC at ...
0
votes
1answer
588 views

How to convert low voltage (< 0.4V) AC to DC

I've made a mini generator for a mini wind turbine. An oscilloscope voltage measurement shows a +0.4/-0.4 V sinusoidal AC current. I'd like to convert it into DC, in order to put a charge and detect ...
3
votes
0answers
197 views

Can AC/DC conversion losses from solar panels be avoided with a Tesla Powerwall?

(background: I'm just playing with numbers, trying to estimate how many solar panels would be needed to fully supply the energy for a home and 2 Tesla cars) I've been reading up on solar panels and ...
2
votes
1answer
92 views

Transformer and a relay in series - but function like in parallel, but not exactly

I've been doing some planning to build a home automation system on top of the existing power infrastructure of my house. The first thing would be making my light switches smart. My original plan is ...
0
votes
1answer
224 views

Simplest AC-DC: charging capacitor at needed AC input voltage

To implement a simple AC mains input circuit to charge a capacitor with low voltage DC I think that it should be possible to connect the output capacitor to the AC line through a diode, and a ...
2
votes
3answers
383 views

Feasibility of very high temperature ac-dc switching power supply

I'm involved in a product design (on the mechanical side, to be clear that I'm not an EE) where we need a very compact ac-dc switching power supply that will take 90-300vac, 50-60hz and output 5 watts ...
2
votes
1answer
515 views

wiring AC switch with DC led

This is a follow up to a previous question I had answered. I'd like to show the following diagram. Here, I have laid out (crudely) a diagram that has 120v-110vAC from the wall going to a push ...
1
vote
1answer
77 views

'Dielectric Strength' parameter meaning for cheap inductior coils

Initially I need an inductor to be used in cheap low-power AC-DC power supply. I'd like to use LNK304 solution: When I reached 1mH coil I found Bourns 77F coils: very cheap (only 8 cents at some ...
0
votes
1answer
3k views

5 pin push button switch with LED AC wiring question

Thank you in advance for any help you can give. This is really my first project like this. I built a shelf in my house based on this picture. and I'm integrating an Eddison bulb lamp into the ...
-1
votes
1answer
91 views

Does order matter when it comes to AC power? [closed]

Is there anything about electricity or the electrical design of AC power strips that dictates in what order the devices should be plugged in? When I say, "in what order", I am referring to the ...
-2
votes
1answer
78 views

Is there a rightside up when plugging in an AC to DC power converter? [closed]

When plugging an AC to DC converter into an AC outlet, does it make any difference at all if the wall wort is "upside down" or "rightside up"? Is there anything about the electrical design that would ...
0
votes
2answers
301 views

Convert high voltage AC (10kV, 60Hz) to low voltage DC (5V)

Is there any easy and safe way to convert the high voltage AC (60Hz, 10kV, such as the voltage on the overhead line) to 5V DC that can be used to power up a micro controller (around 1W power)? We do ...
2
votes
1answer
571 views

AC-DC Adapter - Output lower than rating and what's this 'cont' output for?

I have a Canon AC adapter, Model K30321, that I'd like to use in a project. I'm attempting to test the adapter for correct voltage output. Adapter specs: ...
1
vote
1answer
306 views

Is a charged capacitor in a power supply dangerous?

I'm just beginning in hobby electronics and have made a power supply with a bridge rectifier and a smoothing capacitor (4700uF). I want to put a toggle switch in to turn the supply off and on. Should ...
1
vote
2answers
346 views

Parallel connection between distinct DC Bench Power Supplies

I'm using a 30V DC power supply which is said to be 30V/3A with a switch between series/indep/parallel mode. Connecting the supplies in parallel, we have a maximum of 6A. However, in order to execute ...
0
votes
3answers
221 views

Converting small AC output voltage of a piezo element to DC without IC

I've been trying to find a AC to DC converting circuit that will take a piezoelectric crystal as its input. I have the piezo to a bridge rectifier but all the diagrams I am finding have some kind of ...
1
vote
0answers
50 views

Why do some Arduino relay modules can handle up to 250 VAC but not above 30 VDC? [duplicate]

When you look for "Arduino relay module"s, you usually see one form "SONGLE" that says on it: 10A 250 VAC 10A 125 VAC 10A 30 VDC 10A 28 VDC My question:...
0
votes
1answer
166 views

AC DC adapter voltage regulation

I would like to make a dimmer for several ikea desktop LED lights. This one is plugged on a LED driver (adapter) with specifications: Primary:220-240VAC 50/60Mhz, 0.06A Secondary: constant current: DC ...
2
votes
2answers
147 views

Replace transformer with PWM control

This is my first question on stackexchange so if I do anything wrong, please let me know :-) So my situation is the following: I am working on a power supply module where I need 7 separated +28V DC ...