levitation device troubleshooting

[roger harrison]

I am building a levitation device from a schematic on the internet that uses a 7805 regulator a ah3503 hall sensor a mic502 and a lmd18201 a coil a resistor a led and capacitors. I got it to work for a few minutes but decided to make it a little better?? (big mistake) I have put it together 20 more times even with swapping out all new ic's but it still doesn't work. I've rechecked my breadboard a thousands times but can't find any wiring mistakes. There is a short addendum on the website about locating the capacitors close to different ic's?? Could that be my problem? When I plug in the power about 16 volts pulled down to 5 volts with the 7805 the coil reacts to the magnet I am trying to levitate just like a plain old electromagnet. But when I place my hand close to or touch the wire coming out of #3 "DIR" of the lmd18201 going to #7 "OUT" of the mic502 I can feel it start to sort of buzz and sometimes reverse polarity? Can any one come up with a solution or find a better levitation schematic that is more robust or reliable?

 

[DerStrom8]

Aren't you forgetting something? Where is your schematic? Where is the detailed photo of your setup?

Pulling 16V down to 5V with a linear regulator is wasting a LOT of power, which means the 7805 will get VERY hot. I hope you have it on a very large heat sink with a fan blowing across it.

Have you probed around your circuit to measure the power rails? As Dave Jones of the EEVblog always says, the first commandment of electronics troubleshooting is "Thou shalt check voltages".