runklem

LM358 arrived today and did the trick. Guess it pays to actually follow the directions. Thanks to all.

Thanks for the amp info. Naturally Radio Shack doesn't carry it, so I'll be spending $5 in shipping for a $0.35 part from an online place... oh well. The price for toys I guess. Thanks

Wow, talk about overloading a transistor! (my brain transistor) :o I haven't any idea what you just said...but do you have a solution?

For what its worth, the kit's book says its a TLC272 dual op amp.....?.... r/

Thanks for the replies. As for the amp, I don't know anything beyond it being called a 272. It came with my sons electronics kit, which I have ransacked for this project (don't tell him). As for the transistor. It can't be completely fried as the circuit still works now, with a single LED module. But, that fact that it is failing (non-permanently) with the larger load is certainly possible. Assuming its the transistor, does anyone have a recommendation on what to replace it with? I am not an electrical engineer, but merely someone who can follow directions fairly well and have enought electronics knowledge to just get myself into trouble (case in point, now). I'm not much good beyond V=IR.... So if my current requirement has gone up, then I need more voltage(?), which means taking out the voltage regulator and letting the 12v flow in? Would this not kill the transitor and/or amp?.....Thinking as I type now...what if I let in the 12v, but put a resistor of some magnitude in front of the transitor?...... Thanks

Doh! just lost the whole email 'cause I couldn't attach a .bmp..... ok, take two: Here is the hyperlink to the original project: http://www.electronics-lab.com/projects/motor_light/020/index.html Attached, hopefully, is a schematic of what I did..or my best attempt at a correct schematic. In case its unclear here is what is different from my project and the original. I replaced the LM358 op-amp with a 272 dual op amp (because its all I could find). I also added a 7805 voltage regulator on the incoming voltage, since I've got 12v in. This steps it down to +5v. Finally, the load is 10 LED "modules" wired in parallel. Each module is actually two LEDs w/ resistor wired in parallel. Disregard the R6 in my schematic, that is meant to represent the built in resistor on each LED, not an additional resistor before each module. My voltage source is the 12v battery on my motorcycle. I have the leads screwed directly on the battery with inline 15 amp fuse for safety. Again, the thing works fine on my workbench when hooked to just one LED module. Its stays constant on when hooked to the 10 modules. Any help is appreciated. Thanks

Hi, just built the LED Pulser project from your site, but am having problems. I added a 5 VDC regulator to the V+ as my intention is for this to drive some LEDs on my motorcycle to produce what can best be described as a "breathing" effect for red LEDs around the engine. Anyway, it works fine when hooked up to a 9V battery and one of my LED modules (2 red leds in parallel), however when I hook it up to the motorcycle and 10 modules (in parallel with each other), I get a constant on. No dimming or pulsing effect at all. Not being nearly as smart as I think I am, I am at a loss of what to do to fix this. Obviously changing the amount of LEDs has caused something to go awry but I don't know what to change/modify to overcome this. Please help.