Electronics Design

Dangerous battery charging circuit

I saw this circuit at Facebook at https://www.facebook.com/share/p/1AC9zDA8gR/ I hv been seeing circuits like this i will be wondering what a hell are they publishing like this without shame ! Dangerous, do not use ! This is what I call an “automatic house ingnitor circuit” Lithium battery exploder circuit That looks like a one way

USB charger bad

Another bad and potentially dangerous circuit from Facebook. This is supposed to charge LiIon battery from USB power. Identified problems: – no current limiting – can overcharge the battery – red charging LED will be always on when there is USB power coming in – green charged LED will not turn on when battery is

Bad LED dimmer

https://www.facebook.com/share/r/1MqEUa6oyN/ A bad design that for most control range LEDs are off, then there is some brightness control and then turn a little bit more and you have your LEDs fried. Trying to control LED brightness without series resistor by adjusting voltage going to then is a bad design. The LM317 should have been configured

Bad SSR circuit

I saw this bad circuit posted to Facebook: It at quick glance looks like a FET based solid state relay (SSR) design to control 230V AC. But actually it is not suitable for the application at all. If you connect the circuit like shown, it will not work as planned and many components will be

Bad AI circuits

Still, Ai is not capable enough to create correct diagrams on its own. I wonder if it is posible to post working circuits to Facebook…… mostly only AI crap seems to be posted Example from https://www.facebook.com/share/p/16vJCdn37B/ The left side circuit is almost correct, but for example the control button has only one wire in it,

Transformerless LED supply idea

I saw the following circuit design posted to Facebook. Source: https://www.facebook.com/share/p/1HuYVvXHcf/ What is wrong with this design: No isolation from mains, potentially electrocutes if you touch any part of exposed LED strip. The circuit will only give around 220V/30000ohms=0.00766.. mA current that can light one normal LED but not any long LED strip like shown

Bad amplifier design

I saw this at Facebook at https://www.facebook.com/share/p/1YitRKKmxy/ Can burn loudspeaker and transformer due DC flowing Dc quite probably saturates transformer core-> lots of distortion and very little sound Even if works the transformer is expensive and limits sound quality Very low impedance sound input is less than 30 ohms – which means this circuit does

Touch switch

I saw this circuit at https://www.facebook.com/share/p/16HFEwzkcQ/ The diodes try to charge and discharge the mosfet gate based on static electricity of user touching. Depending on the amount of charge you happen have it might not work at all, might work or could fry the mosfet (they are static sensitive components). FETs are extremely vulnerable to