tobarger

I swapped the IC chips with TLC555 Cmos and the voltage at C8 is better but still only about 1.8v. This is still not near enough to light the LED. With 5vdc applied to the circuit the voltage at C8 is also low.

Thanks audioguru, I appreciate your time and patience. Its rare to find someone thats so knowlegable and quick to help as yourself, you made my day. Thanks again. Tom

Thanks for responding audioguru, 1) What size of battery cell did you try? 1.5v AA and also tried 5vdc straight from a power supply. With 5vdc C8 only charges to approx. 3.5v. Used a logic probe to ring out the chips, IC1 pin 3 is definitely oscillating but I lose the signal on the other side of C2 at pin 6 of IC2. IC2 does not seem to be working (inverting). From my understanding, unless the outputs of both ICs are very close to 180 degrees out of phase the voltage multiplier will not operate effectively. Am I correct in this assumption? When I tried to simulate the circuit in PSpice IC1 is oscillating fine, the output of IC2 is not inverted but slightly shifted out of phase approx. 45 degrees. Then when I add all the diodes and capacitors to the output of IC2 I can't get any meaningful waveforms anywhere in the circuit. 2) What is marked on your Cmos 555's? NE555N S8123 3) Did you use 220uF for C8? Yes, electrolytic Thanks again for your time.

I have been trying to get this circuit posted on your site to operate for three days now. I've followed the schematic and instructions to the letter. Checked and rechecked all connections, replaced components and rewired over and over again. I've even tried to simulate the circuit with PSpice to no avail. I can't get C8 to charge above .7v with a 1.5v battery, so LED D7 will never light. Also,am using CMOS 555 timers as specified. Do you know of any problems with this circuit? Can you give me any advice or information about this circuit? Has anyone else tried to build this circuit? Any assistance will be appreciated. Thanks Tom