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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1answer
80 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
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1answer
84 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 ...
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2answers
71 views

AC to DC convert circuit 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 ...
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0answers
45 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 ...
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1answer
63 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 ...
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2answers
60 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 ...
0
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1answer
59 views

AC - DC Power Supply Non Isolated

I have been thinking of using LNK305P from Power Integrations to integrate an AC -DC power supply in my next project. The application note containing the circuit is here. What things do I need to ...
1
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1answer
310 views

Converting 100mV AC to 1V DC

Hey guys I am looking for a circuit where I can convert 100mV AC to 1V DC and then feed it to my microcontroller's ADC pin. Can any one suggest any circuit to achieve this? I want to interface a ...
1
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1answer
68 views

Why are some AC/DC adapters light while others are heavy?

I was browsing the thrift store and found a nice pair of JBL 2.0 computer speakers, but they lacked a power adapter. They call for a 12V 1A supply. I have a ton of "bricks" lying around, but no 12V ...
0
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1answer
115 views

Looking for circuit diagrams of current mobile phone chargers [closed]

I am writing an investigation into how a mobile phone charger works and I'm required to break down the internals with a block diagram with component explanations. To help get me on track I'm looking ...
7
votes
3answers
117 views

Connecting two DC wallwarts in series - to produce dual DC supply

I have two 9 V, 300 mA wallwarts and would like to connect them in series to produce +9 V, 0 V and -9 V. This can be done with two 9 V batteries (as seen below), but can I do this with two ...
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2answers
144 views

AC DC circuit mixed. Voltage at a point

I'm Computer Science student and I'm having a hard time understanding this task: Answer is: Va for DC = 0V, Va for AC = -1 - 3j Vb for DC = 4.8V, Vb for AC = 1 - 1j I have a couple of questions ...
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0answers
63 views

Modified Sine Wave Inverter to power MPPT circuit/microcontroller and Laptop?

I am going into uncharted territory for my senior design project. I need to build an MPPT circuit to efficiently charge a 55AH or 75AH battery. The design because of my lack of programming expertise ...
0
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0answers
41 views

High Voltage AC&DC transition on PCB

I'm designing a SMPS and drawing layout onto double-sided PCB. Due to mechanical features of design, both AC and DC current should have transition through vertically attached board. For example, input ...
0
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0answers
69 views

Plugging battery backup and AC/DC converter into the same battery

Today, I took one of the UPS (UPS A) the battery out and directly plugged it to bigger 12V battery (so if the electricity is out it stays long). And I also have AC/DC 2000Watt inverter. That inverter ...
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votes
1answer
89 views

Need to make a laptop charger [closed]

I am not an electrician. My laptop's charger burned when we had high voltage 2 days ago. My laptops charger says Output is: 19.5 V and 9.23 A. I am in a country that you can't easily find those kinds ...
1
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4answers
425 views

Can a current be induced in an HDMI cable that runs parallel to a 120v AC cable for 15 feet?

I just went to go unplug an HDMI cable and got shocked from the end of it! The only possible causes of this that I can think of are that the receiving or sending end of the long (50ft) HDMI cable is ...
0
votes
1answer
36 views

What is the name of the IC that runs a low-harmonic power supply?

I'm interested in building an AC/DC converter for low-harmonic applications. Single-phase AC input, followed by a rectifier and a PWM-controlled boost converter. I know there are ICs which are ...
0
votes
1answer
124 views

Relay that detects 240VAC and switches 12V DC

I'm wishing to detect the loss of AC power (in this case 240V) and when this event occurs have a 12V DC circuit go to earth. This will trigger an alarm for users to react to situation. Can anyone ...
0
votes
1answer
71 views

Equivalent sequence/stepper relay to “FINDER - 20.21.9.012.4000”

I am currently looking at this relay: FINDER - 20.21.9.012.4000. Which is step relay, that makes contact AC output active with coil input DC (12V) [which i need]; and disconnects output when coil is ...
3
votes
2answers
1k views

BeagleBone Black - power supply sensitivity

I've bought a AC/DC adapter which per its specifications should output 5VDC and deliver 3A. I was going to use this adapter to power my BeagleBone Black (BBB) with. However, when I'm measuring the ...
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2answers
237 views

Converting 28VDC -> 14VDC at around 200A How do you pull that off with that kind of current?

Current boat has 110AC air conditioners and some small appliances but the rest of the systems are on 12VDC. Genset ate a jellyfish and has to be replaced, so I'm working out options to upgrade/change ...
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0answers
91 views

What controller for a 400W AC-DC SMPS?

I would like to build a big AC-DC SMPS. I built a little one based on ST's VIPer22A. This is a nice little IC that can give up to a couple watts (my design was 5V 1A). It was easy enough to design ...
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1answer
618 views

Using an AC Fan on DC Battery

I have a 30wp solar panel which charges a 28amp 12 V dc battery. Can I use an ac fan (with less power) on that battery? I am newbie to electronics.
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4answers
291 views

home socket with DC voltage

I'm wondering why, in a standard house, instead of using many low power AC-DC rectifier, there isn't a big (like 12V 20~50A) AC-DC rectifier which supplies some wall socket with a DC voltage? In the ...
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4answers
285 views

How do I get a digital signal from a switch?

I want to essentially drive a relay using a switch. For eg: If the switch (AC Voltage : 220v, 50Hz) is switched on, it sends a digital signal to the relay to switch off.
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4answers
3k views

220V AC to 12V DC transformerless and main isolated converter?

I am trying to build a 220/12V AC/DC max 100mA converter without transformer. I tried so much and burned some circuits. at the end I decide to write here. I searched but couldn't find and answered ...
0
votes
1answer
67 views

Having Two AC-DC converters in series

I have two AC to DC full wave rectifier converters and want them to be in series to increase the voltage. The circuit is basically a generator going into a wave rectifier then a capacitor and resistor ...
2
votes
3answers
246 views

no-load voltage on ac-dc adapter

I recently acquired a toy that uses this transformer: but since I live in a 220V area, I cannot use it directly. I have this generic AC-DC adapter: which in theory is all I need because it has a ...
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votes
2answers
347 views

300 amp 12vdc power supply on a standard(American) wall outlet

I am building a project that will draw around 300 amps at 12vdc, for about 40-60 minutes then it will rest for a few minutes. For this projects application it will be very impractical to build a ...
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votes
2answers
1k views

Switching between AC and DC input

Let's say I need to power a 9v device with an input power source that is either AC or DC and changes almost randomly. Is there any way for me to detect in a circuit when AC changes to DC or vice-versa ...
2
votes
2answers
194 views

Coil-less AC-DC line regulator

I'm trying to fix an AC-DC line regulator that I have build and doesn't work as expected. I'm trying to convert AC 220V mains to DC 5V 10mA without a transformer. To do this I'm using an 1uF 250VAC ...
1
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3answers
282 views

LED blinking array using LC-circuit

Basically I want to create a blinking unit to drive my LED's. The LED's are used to be driven at a frequency of ~1.5Hz (that made me choose the values of L and C). So here is my schematic. (I am ...
1
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1answer
722 views

Does a bridge rectifier care that much for AC frequency?

As I understand it, a bridge rectifier is a set of diodes that play a trick of logic that keeps the polarity positive. So, within the context of a household DC transformer does it matter what the ...
1
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4answers
1k views

Powering 28 LEDs in series by 220VAC - simple stabilizer

I have a home-made thingy that I would like to use as a lightning in my living room. It contains 7*4=28 LEDs (red, 1.86V, ...
2
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3answers
5k views

AC adapter: Input power vs Output power

When I look at, let's say an iPad AC adapter, the input/output rating on the charger states: Input: 100-240V 0.45A (AC) Output: 5.1V 2.1A (DC) I know that the ...
1
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3answers
161 views

Picking an AC-DC Converter to Minimize Cost [closed]

I'm trying to design an AC/DC converter to implement into a project I'm working on. The project needs to be isolated from mains and shouldn't require more than 1A at 5V. My question for you is what ...
1
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2answers
357 views

Thinking about LED light bulbs..as full wave rectifiers

Tw questions on LED bulbs. First Qt: Just something I was wondering. Since LED's bulbs are, by definition rectifiers ( I believe they are full wave) would it be possible to use them as such by putting ...
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0answers
104 views

Is it okay to rapidly switch on and off a DC adapter

I have a thermoelectric coller I've converted to a heater which I usually use a normal thermostat to control. I've just upgraded to a PID-based controller which of course is going to be switching ...
3
votes
2answers
493 views

Why have atx power supplies need selector voltage?

I am studying various ATX power supplies schematics and don't understand the need of the voltage selector as switching power supplies work at range of voltages. In most schematics i see the 110V line ...
0
votes
1answer
98 views

Wiring different DC voltages to use 120V AC

I apologize in advance if this is simple. I've only had an intro to circuits class and all we did was analyze existing circuits, and even that's been a while. For a design project I'm trying to wire ...
1
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1answer
516 views

Can I use the output of mobile charger as a DC source for my circuit?

The title explains it all. Can I use the voltage and ground pins from the mobile charger and use it in my breadboard circuit? Is it safe? If it isn't, what is the thing I need to buy so as to convert ...
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votes
6answers
1k views

How can I run a 7.2VDC battery-powered drill off a 220VAC wall socket with limited part availability?

I have a battery drill, but the battery is useless, so I want to power direct from the outlet. I need convert 220VAC to 7.2VDC @ 4A. I can't use a transformer because the high output current, it ...
0
votes
1answer
548 views

Step-down transformer AC to DC voltage conversion problem?

I got a step down transformer from an old black and white CRT TV that is about 18v 0 18v, 10A AC current output. I wanted to convert AC to DC, so used four 1N4007 diodes as a bridge rectifier. When I ...
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2answers
114 views

which ac-dc adapter work with my device? [duplicate]

lets say I loose the acdc adapter of a device, like a laptop or a wireless router, how do you know that another adapter will work with my device? my assumption is that I have to match the same voltage ...
2
votes
3answers
3k views

Making 12V DC from 6V AC

I've got a 1980 Honda XL 185s that has a 6 volt electrical system. The headlight uses a 6V AC, 30 watt bulb powered from the generator. The other lights (tail, blinkers) operate off of the 6 volt ...
3
votes
1answer
419 views

12V 1A DC input filter

I have to design a power input filter of consumer device. It is powered with desktop AC/DC 12V power supply. Max current consumption - 1A. Device has a full metal enclosure. I am considering putting ...
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votes
2answers
171 views

convert ac to dc circuit [closed]

I want to build real circuit, which converts AC signal to DC. AC signal looks like below: Its period T is about 2 seconds. At the output I want to get DC as shown in the right graph with voltage ...
2
votes
3answers
1k views

Can I use a 3-wire AC adapter in a DC circuit?

I am reading through the excellent book Make Electronics and am in a chapter that suggests getting an AC adapter, cutting off the connector at the end and stripping the rubber outer coating back to ...
0
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0answers
111 views

power supply for 12 volt impact wrench

I want to power up a 12 volt impact wrench (without a car) using the right ac / dc converter but the device reads "13 amp max current"... Should I go with a 13+ A power supply, or I can use this 8.3 ...