Questions tagged [transformerless]
Transformerless power supplies produce a low voltage from AC mains without using any kind of transformer and without providing any safety isolation.
67
questions
-1
votes
4
answers
210
views
6 amperes in transformerless power supply [closed]
Can we get more than 5 to 6 amperes in a transformerless power supply by choosing these values:
Don't take the values in drawing as exact.
C bunch in parallel could be polarized motor cap (100 uF/...
- 171
0
votes
0
answers
72
views
Glue gun series dropping capacitor
I have a 40 W on label glue gun for 230 V socket, PTC element could be 20 W as some manufacturers use 20 W instead and label it as 40W .
I want to add a voltage dropping capacitor to increase its ...
- 171
0
votes
1
answer
165
views
What’s the explanation on why the outlets wires are on the same coils?
Working on fixing a once upon a time good soldering station so I thought.
Inside the soldering station there’s two transformers, first one for the soldering iron that has an primary of 115 V and ...
0
votes
0
answers
58
views
Why does my power supply circuit not function correctly when connected to a load circuit?
My transformerless power supply on the left side of the voltmeter outputs 24V/12V until I connect it to my load circuit on the right. The voltage coming out becomes and stays at 1.5 V at most and I ...
- 1
1
vote
4
answers
273
views
Do voltage multiplier circuits and transformerless power supplies have functional similarity? [closed]
I saw diagrams of voltage multipliers like in the picture below. To my understanding, it seems like they have the same function as transformerless but the use of a voltage multiplier is to increase ...
user320546
3
votes
3
answers
227
views
Confusion about DC output voltage in this circuit
I am building a transformerless power supply to power 60 RGB color changing 2 pin LEDs in series from 230 VAC mains. These LEDs need DC to function properly.
In the circuit below, I understand that ...
- 31
7
votes
5
answers
1k
views
Converting 24 VAC to 5 VDC with small output current
I have a transformer which outputs 0.33 A at 24 VAC. I would like to rectify this down to 5 VDC and minimal current, 50 mA being the maximum. I came across the following schematic which seems to be ...
- 85
-2
votes
1
answer
185
views
Is it possible to make a 220 VAC to 12 VDC, 5 A transformerless power supply?
I need to make a power supply that takes 220 VAC and outputs 12 VDC and can handle 5 A.
Where I live there are no flyback transformers for sale and importing them is a big hassle.
I have some ideas ...
- 287
1
vote
1
answer
488
views
Simple transformerless 3.7VDC to 220VAC [closed]
I am looking for a circuit design that could be capable of inverting 3.7VDC to 220 VAC. The maximum current draw is below 50 milliamps, and this circuit shouldn't have problem like voltage drop as ...
- 79
0
votes
0
answers
53
views
Problem with how circuit work in china transformerless voltage sensor pilot lamp
I want to actually understand the circuit completely but for the specific, i want to really understand how this circuit can actually output ac voltage in OUTPUT_SENSOR point and the waveform is ...
0
votes
3
answers
245
views
How does this "single-ended push-pull with transformerless driver" work?
I'm studying the circuit block below in an Italian textbook, "Dispositivi e circuiti elettronici", by M. Gasparini, D. Mirri.
The circuit is called "single-ended push-pull with ...
- 163
1
vote
4
answers
513
views
An inverter without a transformer?
I am trying to build an inverter without a transformer. I want to use a 12 V battery connected to a boost converter which will boost the 12 V to 120 V, then simply attach an H-bridge to the 120 V ...
- 146
0
votes
1
answer
417
views
Rectified 230VAC to 24VDC
I am building a simple motor control application, driving a series wound motor that runs on rectified 230VAC. Originally, it was controlled by a pendant switch connected to a 7 pin connector. The idea ...
- 115
0
votes
0
answers
173
views
How to build a simple 12VDC-12VAC transformerless inverter using transistor
I am looking for a circuit diagram or an explanation on how to build a 12VDC-12VAC inverter circuit without using a transformer or an inductor of any kind.
I want this circuit to be as simple as ...
-2
votes
2
answers
518
views
Can we make a transformerless 220V to 12V converter without a Zener doide?
I saw many circuits have a Zener diode, but a guy from Youtube lighted up a 12V LED without a 12V Zener diode in the cicuit.
How is that?
- 169
0
votes
3
answers
963
views
Capacitive dropper power supply for LED - zener/decoupling capacitor?
Let's say you have a standard capacitive dropper power supply like the following (from Wikipedia):
I understand that these work well for driving LEDs since they act like a constant current source. I ...
- 79
1
vote
2
answers
542
views
Capacitor protection in transformerless power supply
I am designing a capacitor based transformerless power supply for a WiFi-based device which will be on for 24x7, with an input of 230VAC at 50Hz.
For almost 80% of the time, the device would consume ...
- 71
1
vote
1
answer
374
views
Voltage dropping capacitor doesn't drop the voltage?
I am going to make a transformerless power supply.
Here I am using a 105J 400V polyester capacitor to drop the voltage.
I connected the capacitor and AC main in series, but when I measure the voltage ...
- 11
0
votes
0
answers
62
views
Is it possible to connect a switching buck converter to a simple transformerless power supply?
Many cap based transformerless power supplies intended to use with 5V circuits, use a 5.6 zener diode to regulate ouput voltage. I'm using below circuit and the calculator here [which is based on the ...
- 1,807
1
vote
1
answer
90
views
Why using capacitor in transformer less ac to dc converter
I saw many transformer-less power supplies using capacitive resistance of a capacitor.
But I don't know exactly what the reasons are for using capacitors instead of normal resistors .
I guess two ...
0
votes
1
answer
454
views
What kind of power supply is best for IoT application?
I am trying to make some IoT devices to fit in wall outlet. There is an issue with power supply. I have to feed my circuits from 220V outlet and there is a limitation in size.
I tried to use some HLK ...
- 17
0
votes
2
answers
627
views
6.2 V zener shows lower voltage (Multisim)
I have this circuit with a 1N4735A 6.2 V zener diode. I am trying to figure out why am I measuring 5.1 V across it. The circuit is a transformerless power supply with more or less 60 mA of maximum ...
- 1
2
votes
2
answers
659
views
Capacitor Vrms vs Vpeak Rating in Transformerless Supply
Why is it that when calculating for voltage across the capacitor in transformerless power supply we need to use peak voltage not RMS voltage value.
To be clear I am referring to the rating of C1 in ...
- 29
0
votes
0
answers
136
views
Capacitive Power Supply Torch
I'm an amateur at electronics circuitry and concepts. I have designed a simple capacitive power supply using few web images and brief lessons. I understand that this type of transformerless power ...
- 91
2
votes
1
answer
594
views
Adding ethernet jack and transformer to device designed without one
I'm attempting to add an RJ45 Ethernet jack to a commercial device without one by replacing an embedded WiFi module, which, according to its datasheet, is connected to the rest of the system as ...
- 151
-1
votes
1
answer
285
views
Transformer less Power supply's waveform is Noisy
Hi I want to measure the mains voltage using transformerless power supply. the output of the supply is fed to an optocoupler and later read by a microcontroller.
The problem i am having is that the ...
- 101
0
votes
5
answers
1k
views
Resistor & capacitor are getting too hot
I made a transformarless power supply with capacitor. When i connect it on ac, it light the leds. But after some second the 100ohm resistor and 470uf capacitor get too hot. Its too hot that i could ...
- 3
-1
votes
2
answers
145
views
How to obtain 360vdc from 240vac for audio use without a transformer?
I'm in the process of creating a tube guitar amplifier with an output power of ~6w (fender vibrochamp AA764) which requires the use of 360-400vdc. How could I obtain such a voltage from mains without ...
0
votes
1
answer
147
views
+/- 96 V transformer less power supply design
I know this is a dangerous practice, but obtaining a transformer to make a vacuum tube power supply in my country is prohibitively expensive. So i have to go for transformer less psu. I am just making ...
- 33
1
vote
1
answer
481
views
Modify Transformerless Power Supplies
Based on this article:
https://hackaday.com/2017/04/04/the-shocking-truth-about-transformerless-power-supplies/
I have some rf wireless plug outless which use transformerless power supply.
I would ...
user213858
-1
votes
2
answers
92
views
Prevent transformerless powerless supply going full voltage on O/P in case of open circuit
I would like to automate two of my lights using Nodemcu and a 5 V relay board. I am planning to power the relay and Nodemcu with a transformerless power supply. Is there a way to prevent full voltage ...
user189789
-2
votes
1
answer
118
views
What resister I want to use to drop voltage for LED? [duplicate]
I am going to connect 10 led in series without a transformer.
Now I want to know the value of resister to connect 10 led in series
and please give the calculation method
thank you.
0
votes
1
answer
367
views
What types of signals can a dynamic microphone generate?
And what design generates what type of signal property?
For example there are dynamic mics with or without output transformers. Do they differ in the type of signal outputted?
Do most dynamics ...
- 3
9
votes
7
answers
7k
views
Transformerless power supply
I'm looking for building a power supply circuit that will convert 230VAC to 5VDC in order to power up an Atmega328P. I also want this to be as small as possible.
I know a transformer is one option ...
- 123
-3
votes
1
answer
110
views
Transformerless supply [closed]
I am desigining a transformerless supply with two cap in series .if I measure the voltage across 1st cap it is 80 volts and same for other but net voltage measure across these two caps are 240 How and ...
-1
votes
3
answers
417
views
2kV AC step down to 5v without using transformer [closed]
I'm doing an industrial project, i need to step down the high voltage of 2kV to 5V, is it possible to step down to around 5V without transformer, is there any other alternatives? please suggest me :)
- 9
2
votes
2
answers
4k
views
ATtiny13a capacitive power supply
I would like to power my Attiny13a MCU with a transformerless capacitive power supply. The MCU itself needs only a few milli amps and it will drive 2 LEDs at 15mA each through it's digital pins. So I ...
- 678
-2
votes
2
answers
219
views
Capacitive Power Supply Zener Resistance
I am designing a Capacitive power supply, I found someone who did the circuit shown in the figure. I don't know what is the usage of the 47 ohm resistor in series with the Zener diode (12V MELF ...
- 477
0
votes
2
answers
1k
views
Polypropylene capacitor power supply [duplicate]
I found some articles talking about transformerless power supplies, and I have uploaded the schematic of such a circuit. Does anybody have an idea about the pros and cons of such a power supply? Also ...
- 582
-4
votes
2
answers
1k
views
LM317 output voltage to 0 V with transformerless negative voltage created through a buck converter
I try to construct a shut down pin or a feature which can set the output of LM317 or LM78XX with negative voltage that is created through a transformerless buck converter.
A buck converter having ...
- 1
1
vote
1
answer
236
views
Identifying unknown components in transformerless power supply
So my dad found one of these voltage converters lying around.
I was quite curious what components it had as it is very lightweight (transformerless) and boasts a good 1600W @ 110vac (14.5A) on the ...
1
vote
1
answer
982
views
Safety of zener diode based non isolated power supplies
Are the following zener diode based non isolated power supplies safe to use with a touch based application?
I would assume, the circuits are safe if they completely sealed (including the touchpad). ...
- 305
1
vote
1
answer
319
views
Capacitive power supply - Bleeding resistor reliability considerations
We are using a capacitive power supply for one of our applications.
The X2 capacitor (330nF in this case) provides good reliability with respect to failing safely/open and good over-voltage ...
- 10k
21
votes
8
answers
5k
views
Two resistors in series
I know the summation equation for two or more resistors in parallel or series, and I know two parallel resistors will give more power.
But sometimes I saw some circuits that used two resistors in ...
- 1,838
0
votes
2
answers
2k
views
TVS selection guidance to protect against overvoltage on AC line
I used this link to generate a 5VDC (1A) from the 220Vac power source, the circuit itself works perfectly fine but I want to make sure that the overvoltage on the AC line won't damage my board.
I ...
- 19
4
votes
3
answers
5k
views
Designing small size AC/DC to provide 3.3 V for MCU [closed]
I have designed ESP8266 based light switch, that is controllable via web page or a push button. Light is being switched with use of Triac (TIC206) through optocoupler (MOC3041). Prototype works as ...
- 181
6
votes
2
answers
1k
views
Reducing volume for a split-phase 230VAC@60Hz sealed power supply providing 5VDC@50mA
I'm a hobbyist interested in re-designing and implementing a DC power supply providing a \$+5V_{DC}\pm 200mV\$ output with a current compliance of \$50mA\$ (I could live with \$30mA\$ successfully) ...
- 77.4k
0
votes
1
answer
2k
views
How to calculate output voltage of a non polarized capacitor?
How to calculate output voltage of non polarized x-rated capacitor (230VAC 5A 50/60Hz)? (which depends on input voltage) as like as the calculation of output current here tutorial
table here tested ...
2
votes
2
answers
2k
views
Isolation of the transformerless power supply
One of the disadvantages of transformerless power supply is the isolation problem because of the absence of the transformer. My question here is : Doesn't the capacitor in series at the input do the ...
- 1,491
0
votes
1
answer
270
views
Can tranformerless inverter topology be used in UPS with a regular battery (12V 7Ah)?
While searching for transformerless inverters in the IEEE site, most of them seem to be about grid connected Photovoltaic inverters. Removing transformers will increase the efficiency at the cost of ...
- 161