See my post #38 in this thread: http://forum.allaboutcircuits.com/showpost.php?p=179831&postcount=38

This blows my mind! How the hell did I miss this post? I remember the 555 with Darlington Outputs but I missed this one with the FETs. I could have saved myself a lot of time by just posting your link!! This has been a long thread.....

 

This blows my mind! How the hell did I miss this post?

That happens to me all the time; it's easy to miss the last post or two on a page of a multi-page thread.

I remember the 555 with Darlington Outputs but I missed this one with the FETs. I could have saved myself a lot of time by just posting your link!! This has been a long thread.....

Funny though that you arrived at a very similar solution to what I'd posted a few days ago.

I didn't bother with the pull-down resistors on the gates. However, it would be a good idea to put a 10k resistor across the rails, just to drain off any residual charge when the power to the flasher is turned off. LEDs can glow for quite a while at low intensity when supplied by a capacitor.

 

well got it working beautifully on my breadboard, now if only I could remember how to solder. Seems I fried something when soldering it all together and gotta try again. This project has been headache after headache.

Thank you guys for all your help.

 

well got it working beautifully on my breadboard, now if only I could remember how to solder. Seems I fried something when soldering it all together and gotta try again. This project has been headache after headache.

Thank you guys for all your help.

Just remember to apply the iron first for a duration of one second and then the solder. Many people do the opposite which almost always leads to a cold solder joint. Also, after you apply the solder, take it away and hold the iron for a couple more seconds to make sure it's heated up. That's all there's to it!

Austin

 

Remember, cleanliness is everything. If your soldering iron tip isn't clean and tinned properly, you're already starting with a big disadvantage. If you're using a pencil iron, it should be rated between 20-35 Watts. Don't use a "soldering gun".

Isopropyl alcohol (90% or better) applied with an acid brush works well for cleaning components. Careful, it's flammable - and burns with a nearly invisible blue flame. Don't use the 70%; too much water in it. If you don't clean the parts after plugging them in a PCB, your finger oils will keep the solder from flowing.

Use small diameter 63/37 solder. If you feel you must, use a tiny bit of rosin flux. Don't forget that finger oils on the solder will make soldering harder.

If your component leads have oxidized from excessive handling or sitting around for awhile, 3M Scotchbrite pads work great for getting the corrosion off. I keep a few kicking around my workbench.

Don't forget that those power MOSFETs are very sensitive to static. Just one tiny "zap" and they're toast. If you can walk across the floor and get zapped on a doorknob or light switch plate screw, you need to be extra careful about ESD.