Questions tagged [ac-dc]
Questions regarding the safe and effecient design and implementation of AC voltage to DC voltage supplies. Typically Mains to some lower DC voltage.
267
questions
0
votes
2answers
50 views
Step down transformer alternatives
Does anyone know if I can use a Quam TBL 25 volt 4 watt audio transformer to step down 120 volts to 12 volts, later to be rectified to a 12 volt dc power supply? I know 12 volt power supplys are ...
-2
votes
1answer
56 views
What is the power consumption of a 12V adapter running 4 CPU fans?
I have a quick question here.
I am not a ECE guy and just a hobbyist trying to tinker while quarantined.
I have 4 CPU fans (120mm) laying around and I'm trying to re-purpose them as a small fan.
...
0
votes
0answers
26 views
Techniques for measuring the ripple current of SMD electrolytic capacitors
I am currently creating a test plan for an AC/DC converter (90VAC...264VAC -> 12VDC) I've been working on. Since the output electrolytic capacitors are of SMD type, I am trying to come up with ...
0
votes
0answers
18 views
Using an ac adaptor for a dc only tv [closed]
I have a 12 V 1.4 A max dc only TV. How do I get the right ac to dc adaptor for it. I have a ac to dc adaptor for another TV but I am afraid it might blow the solar TV if I use it.
0
votes
0answers
21 views
where to find exact definition of i/p and o/p as used to define insulation resistance for AC DC converter?
Most AC DC converter datasheet use I/p and O/P to define insulation resistance
I am looking for the exact definition of these parameters as used in this context
( I know their definition for ...
0
votes
1answer
61 views
What does it mean for a power supply to have an output range?
I had a power supply blow and I replaced it with one from the same company with the same model number. The new supply has lightly different specification than the old supply. Oddly (to me) it gives ...
1
vote
1answer
44 views
Full charged 12V battery with AC converter “empty” within one second - voltage drops, converter beeps
I have the following setup for solar power, which worked well until recently:
solar panel <--> solar charge controller <--> small (car) battery <--> converter: 12V DC to 220V AC <--> my ...
0
votes
0answers
37 views
Need help wiring a power supply (UK)
First time here so apologies if this question is in the wrong place. Also i'm a bit of an amateur with this sort of things to go easy on me.
I've bought a power supply to power a DC charger for LiPo ...
0
votes
0answers
30 views
Use old battery pack charger as DC power supply?
I have an old charger for NiCd battery packs. It is labeled with:
Input: 230 V~, 50/60 Hz, 33 W
Output: 4.8 - 12 V DC, 1.4 A
I opened it and found a transformer and two circuit boards. I made a ...
0
votes
2answers
100 views
AC TO DC Converter IC
I am using a small circuit which needs 5V DC input and total current consumption of the circuit is 300mA. I have been using the small size ac to dc converter modules, but now i am searching for a ...
0
votes
1answer
42 views
AC-DC Switching Power adapter Unstable Voltage [closed]
I recently bought a AC-DC (14V DC, 3A) Power Supply on eBay to power a Samsung Monitor, and it does power on my monitor. It is not the monitor because another power adapter I have works with it.
...
0
votes
3answers
101 views
Powering small DC load ( 1W ) using 220V AC supply
I am trying to design a small control circuit for controlling large currents (not too large, around 200W, AC 50Hz). I have kept in the AC circuit isolated from the DC control circuit. But the problem ...
0
votes
2answers
108 views
Is It Posible To Have Step Up Power Supply Without a Transformer?
I am trying to design a high voltage low current power supply. My purpose is to design it without a transformer. For example circuit like this :
My input is 220V AC after this circuit I am going to ...
0
votes
1answer
91 views
misunderstanding of Voltage output of a 3-phase rectifier
I simulated a 3 phase rectifier :
I obtained V1 and V2 as plotted below :
I dont understand that waveform as i'm supposed to obtain a DC voltage.
Can someone explain me how it comes that i got ...
0
votes
0answers
46 views
How to ground external AC voltage (18V) to Arduino?
I have a project where I need to read 0-18 Volts AC in Arduino's input (0-5V DC).
So I did a circuit with a diode (half wave bridge), voltage divider, and a RC circuit where I tested some values for ...
0
votes
2answers
68 views
Positive and negative rail for op amp circuit
I need a positive and negative rail to power an op amp
Since it's an op amp for a voltage reference, would using a circuit like this one be enough?
Input voltage is unregulated 37 volts, with 4.7k ...
0
votes
3answers
167 views
Discrete linear voltage regulator
I am trying to make a discrete component linear power supply. This schematic seemingly works but it doesn't work when I build it on my breadboard.
I am taking 110 volts through a transformer down to ...
0
votes
1answer
81 views
AC to DC conversion: is this an appropriate implementation?
I understand that a 20v AC converter supplies 20V RMS AC. I wish to convert this to 20v DC and so have drawn up a schematic for this which includes: the AC to DC conversion, regulation, smoothing, and ...
0
votes
1answer
42 views
Output current and voltage levels regulation in ac/dc adapter
On the picture below is the output circuit of AC/DC adapter. I understand how voltage level contol works, but I don't understand how exactly current limitation works and how should I calculate ...
0
votes
2answers
39 views
Is this a reference of an AC/DC REGULATED adaptor?
I need to choose an 230 VAC / 12 VDC converter which is regulated, that-is-to-say I need the voltage to be 12 V with a current of 0 to 5 A.
I found this one because it is the cheapest (price really ...
0
votes
0answers
87 views
Flyback converter with dual outputs (12V / 5V)
I came across the following flyback converter circuit, which has a dual output (12V and 5V), but I am unable to figure out why the secondary windings are connected in series.
Based on the datasheet ...
0
votes
0answers
50 views
Energy Meter power supply advice/help
I've been assigned to start working on a smart energy meter project, it's been like 10 years since I put any work in AC. I would be sincerely grateful for any constructive advice. Now the 3-phase ...
34
votes
3answers
6k views
Computer power supplies usually have higher efficiency on 230V than on 115V. Why?
As seen here in the example, this particular power supply (and most others too) has higher efficiency when running on 230V. Given that computer power supplies are usually required to output a ...
0
votes
1answer
74 views
How to choose AC/DC adapter - high voltage low current vs low voltage high current
I got an LED light kit, 2 lights, each takes 60W, at 12-30V.
I'm planning to use these lights separately, and need to choose between:
12V, 5A adapter
24V, 2.5A adapter
Both will give me 60W, but ...
1
vote
2answers
55 views
How do I safely connect a light switch button to the secondary side on a board?
I designed a special light controller board. It has a primary side that is connected to AC 230V. There are a certified AC/DC converter module and a relais, bridging the air gap between the primary and ...
0
votes
0answers
32 views
Can I use AC voltage from myRIO to power stepper motor?
I am using easydriver and arduino for a stepper motor provided on this website
The motor is 17HS3401S Stepper Motor and I think this is the correct datasheet found on the internet for the same. ...
1
vote
2answers
74 views
Laying out power electronics on analog signal board, practical advice
to keep this brief I am designing some audio circuitry and also need to design the power supply. The barrel jack in the schematic below sees 18VAC and I am converting that to +/-15V DC rails.
So to ...
0
votes
0answers
41 views
Power Supply Design 230 AC to 80V DC - multisim and real components
I am an young student that was tasked to build a power supply which will convert single phase 230V AC into 80V DC to test specific DC motors (custom made). I only know that under normal operation and ...
0
votes
1answer
35 views
Protection circuitry for AC/DC converter
I'm using the RAC02-GB (Datasheet) as an AC/DC converter and I'm confused about the protection circuit they included in the datasheet:
I want to make sure the AC/DC converter has the proper external ...
0
votes
0answers
68 views
Why does rectifier output is showing DC instead of pulsating DC
I am using below circuit for PFC.
Before connecting coupled inductor's auxiliary output to the IC's Vcc, I wanted to make sure that it is coming properly or not.
So when I probed the red dot in the ...
0
votes
2answers
72 views
Determine the resistor required for a circuit [closed]
If I want to supply power to a device that is rated for about 2V using a DC source of 12V. How can I find the resistor o should use.
0
votes
2answers
86 views
AC/DC Converters in Series with the Same AC Source
Would it be safe to connect two identical AC/DC converters in series if they share the same AC source? My concern is that the negative DC output is grounded somewhere in the converters causing the ...
0
votes
2answers
49 views
Can this receptacle power this power supply? [closed]
My car has a wall-style AC receptacle in it. It is merely marked 110V 150W. It is not mentioned in the ownerās manual. Iām curious if it can safely power this laptop power supply:
0
votes
0answers
67 views
PFC boost converter is not stepping up the voltage
I am making a PFC circuit for AC-DC converter. I am facing a weird issue. As per my design the output of the circuit should be 390VDC, but I am getting 311VDCrms with ringing (overshoot 360V, ...
6
votes
4answers
1k views
Converting 8V AC to 8V DC - bridge rectifier gets very hot while idling
I am tinkering with an Arduino and recently had to convert 8V AC to 5V DC in order to run it.
The project is a custom doorbell, which gets the power from the doorbell transformer (transformer is ...
0
votes
0answers
35 views
AC adapter won't power fan at full speed [duplicate]
I have a spare 92mm case fan rated 12V and ~600mA I've used to build a solder fume extractor. When I was prototyping it, I tested the fan with a 12V 2.5A AC adapter and it worked fine, ran at full ...
0
votes
0answers
83 views
Astable 555 used for AC to DC Halfwave to DC stable conversion, is what I have done correct?
I have this falstad-circuit:
And here it is per request, as a SCH file screen:
I'm trying to use a 555 astable to convert a variable AC with maximum of 12V (coming from Bicycle Hub) to 8VDC, ...
0
votes
0answers
94 views
Use Triac as SMPS to get DC voltage
I want n 12V 1A supply for a project. I want a transformer-less topology.
I was reading and experimenting with readily available traic based dimmers. They use phase control to cut the input voltage ...
1
vote
2answers
486 views
How to find the right smoothing capacitor for rectification circuit
I am creating a power supply which will need to convert the 24vac to 5vdc. I am thinking of using a rectifier to convert ac to dc, then a capacitor to smooth out the voltage, then an LM2596-5 to drop ...
3
votes
3answers
290 views
Why aren't non-isolated DC-DC converters made for high wattage applications?
I am new to electronics. I am presently studying DC to DC converters.
One thing I noticed is that most of the people are using isolated stepdown converters like half bridge, full bridge, or resonant ...
1
vote
1answer
85 views
(230v)AC-DC(12v) wall adapter flashes when connected to dc to dc buck converter [closed]
So I used a common 230vAC to 12vDc (1AMP) wall adapter with dc jack like this
and converted to 5v using a dc to dc buck converter same as based on lm2596s
But the adapter LED starts blinking (...
0
votes
1answer
336 views
SMPS 5V without load, fluctuation on load TOP258PN [closed]
I am using PI Expert Online (this) to design a smps circuit for 5V, 2.5A output. I already have TOP258PN IC with me so built circuit for that.
Change from schematics: I am not using choke and using ...
4
votes
4answers
527 views
Is DC-to-DC (24 V to 12 V) buck conversion typically more efficient than AC-to-DC (110 V to 12 V) conversion? [closed]
While building an online UPS system, I'm basing the choice to eliminate as many AC inverters from the system as possible because of the assumption that DC-to-DC conversion is more efficient than AC-to-...
2
votes
3answers
119 views
Please help me understand how to add AC power to my DC device
I have a device that runs off of three D batteries. I would like to be able to add a power cord so that I can plug it into the wall and run it off of that instead. I would also like to still be able ...
3
votes
1answer
226 views
Different Wattage Solar Panels for Home [different Voltage/Ampere]
My current solar system for home
12V 100W polycrystalline Solar Panel.
12V 75Ah Lead Acid solar tubular Battery.
PWM 12V 10A Solar Charge Controller.
12V Input and 200VA Output Inverter.
Current ...
1
vote
2answers
220 views
Power drop on AC-DC converter due to relay
A uController circuit is powered with an AC-DC converter. This circuit in turn acts on some relays to turn on and off some loads. We have two bi-stable relays and another simple relay (Omron G5DN-1A) ....
2
votes
4answers
195 views
300VDC to 24VDC voltage converter - Cheapest implementation
In an application, 100+, 100W 24V halogen lamps need to be individually controlled and run simultaneously. They stay on for a few seconds at a time and need to have very constant irradiation.
...
0
votes
2answers
66 views
How to insulate DC from earth noise while keeping it referenced to it
I have an AC/DC converter (220 to 24) inside an electrical cabinet. The 0VDC is referenced to earth, like this (couldn't find a symbol for an AC/DC converter in the schematic editor so I made a dirty ...
1
vote
2answers
118 views
AC “chopping” power supply inrush current problem
I've made a simple AC to DC chopping/switching power supply circuit (I'm not sure if it's called that) as shown below. in the left part of circuit (which is the gating/chopping part) when the ...
0
votes
2answers
82 views
3.3v Powersupply
I have been needing a 3.3 volt power supply that can use at least 12-24 volts ac dc in. I have looked online and managed to make this schematic
but I have no idea if it works.
I was hoping if you ...
