Questions tagged [capacitive-power-supply]
The capacitive-power-supply tag has no usage guidance.
11
questions
0
votes
2
answers
104
views
Why is the Relay "Chattering"?
I have this circuit which measures if there is under/over voltage from the AC mains voltage and it consist of two parts:
Part one: measuring the input voltage (I had it cropped because it is not the ...
0
votes
1
answer
242
views
Why are SMD components not good for high power applications?
I have been using this capacitive power supply to drive a circuit (an OP amp and relay), but what I can't understand is that when I tried using an SMD resistor (R2) after some testing (turning on and ...
0
votes
4
answers
440
views
Why is the LM7812 getting hot in this circuit?
I have made this circuit. It works fine with normal Zener diode, however when I replaced it with the LM7812 it works fine but as time passes the regulator keeps getting very hot although the load is ...
0
votes
2
answers
180
views
What is the alternative for a capacitive power supply? [closed]
I am trying to make a UPS, which will need to pass safety regulations. I need to detect:
When the mains AC voltage is present
When the mains AC voltage is under/over voltage
I thought of using a ...
5
votes
1
answer
289
views
Any thoughts on a supercapacitor battery project?
Just some insight: I am fifteen and have been researching capacitors for a while now.
I have come up with the idea of building a supercapacitor power supply unit solely to power some small electronics ...
1
vote
2
answers
359
views
Transistor keeps failing in a capacitive dropper circuit with TRIAC
I'm trying to build an automatic night light circuit based on some designs I found online.
Here's the circuit I built:
The problem is that the transistor BC327 ...
- 161
10
votes
4
answers
1k
views
Night light broke after trying to dim LEDs
I purchased a cheap night light that plugs directly into a 240V wall outlet. It has three color changing LEDs.
The problem was, those LEDs were way too bright. I decided to modify that night light a ...
- 1,097
4
votes
3
answers
1k
views
Use of different diodes in a bridge rectifier
I'm repairing the circuit for a motion-activated LED light. The PCB uses a capacitive dropper circuit as the power supply. Photos of the PCB and the corresponding reverse-engineered power schematic ...
- 1,298
1
vote
1
answer
107
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 ...
2
votes
2
answers
770
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
1
vote
2
answers
1k
views
Connecting DC Common Node (Ground) to Three Phase Neutral
I know I shouldn't. But I just wanted to ask due to a specific requirement. I also searched the forum but couldn't find any similar question. Please give me a link if there's any.
I'm asked to modify ...
- 35.5k