• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Electric shock through simple series capacitor mains power supply

Status
Not open for further replies.

Willen

Well-Known Member
Hi,
Look at the attached sample circuit (from the internet) first below. Many cheap devices are being controlled by such power supply like some mains LED lamps, simple colorful flashing LED lamps, torch lights etc. As my experience, in a tourch the power supply was charging its 6V battery of a tourch. I was touching battery's poles but during turning ON and OFF the switch was making little loud sparking and noise (actually all the such power supply makes sparking and noise always during switching ON and OFF or during plugging IN or OUT). And exactly as sparking, I was feeling shocks in my fingers! What and how was that shocking?
 

Attachments

Last edited:

Willen

Well-Known Member
Ops, then what happels if the LEDs or some IC are getting power through the circuit? Probably the load circuit may not be alive more than few months, specially in the place like mine where mains power failure is more than 50 times every day.
 

JimB

Super Moderator
Most Helpful Member
How many times does it have to be stated here and on other electronic forums, that transformerless mains power supplies are dangerous.

Such power supplies must only be used when there is NO POSSIBILITY of touching the wiring or components.

JimB
 

Willen

Well-Known Member
I am not making these supplies but many cheap devices I bought have such power supply. So I am worrying about them. If their output is very rough and not stable, it's dangerous to human but also dangerous to its load circuit/device? Probably the device powered by such supply won't be working more. So feeling like to add some components before and after the power supply like mains filter etc. What you prefer to add specially before the power supply as mains filter? (I have fuse, NTC, power resistors and inductors )
 

schmitt trigger

Well-Known Member
You mentioned it correctly: cheap devices.

The only reason that transformerless supplies exist is the low cost. They are dangerous, they are unreliable, they have poor performance, but hey! who can't resist a bargain?
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top