Register to reply

Did I just fry my IC555 ?

by LordVader88
Tags: ic555
Share this thread:
LordVader88
#1
Dec20-12, 08:08 PM
P: 7
Hi, 1st time poster, long time student/hobbiest of math, physics, most sciences. Just getting serious about electronics lately so I made my 1st 555 circuit ever

I made this blinker , it's a short vid with a very simple schematic in it, he draws it as he goes towards the end. I'm using 5V from an old printer PSU, I used 2 series of 2x 4.7kΩ, the circuit only uses "capacitance" in one place.
http://www.youtube.com/watch?v=oQrrxiFLoBQ

I had it working fine and I was trying different capacitors and series/parallel caps.

Then I put a 33kΩ between the neg side of the single cap and pin 1 of the 555 (should of had it before the cap to make a little RC series), and it blocked the current almost completely.

So I took it out and now the circuit won't blink anymore. If I place a short where the cap goes (between pin 1 and 2) the LED lights up and says on. But if I use a cap, the LED lights up for the correct amount of time, but never comes back on. Then if I reverse the cap (not ideal I know), the LED will light up for the correct time.

So I can get the LED to light for the right time, but it never comes back on.

The resistors all still measure correctly, so what happened?
Phys.Org News Partner Engineering news on Phys.org
DIY glove-based tutor indicates muscle-memory potential
Tricorder XPRIZE: 10 teams advance in global competition to develop consumer-focused diagnostic device
Study shows local seismic isolation and damping methods provide optimal protection for essential computing equipment
NascentOxygen
#2
Dec21-12, 07:30 AM
HW Helper
Thanks
P: 5,360
Replace the IC. If the new one works where the old one wouldn't, I leave you to draw your own conclusions .....
LordVader88
#3
Dec21-12, 08:13 AM
P: 7
only 1 I had, I made another 555 circuit and it doesn't work right either

So I'll have to make some 741 circuits, at least I have a few of them


Register to reply